The 1st Annual TSBE EngD Conference - reading.ac.uk...In November 2009, Jeremy ... Processes and NPD...

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The 1st Annual TSBE EngD Conference

University of Reading

Whiteknights Campus

July 2010

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Proceedings of 1st TSBE EngD Conference

Held at Henley Business School, Whiteknights Campus, Reading,

RG6 6UD

6th July 2010

© TSBE Centre, University of Reading 2010

Organised by:

Technologies for Sustainable Built Environments Centre

Physics Building

Whiteknights PO Box 220

Reading

Berkshire

RG6 6AF

No responsibility is assumed by the publisher for any injury and/or damage to

persons or property as a matter of products liability, negligence or otherwise, or

from any use or operation of any of the methods, products, instructions or ideas

contained in the materials herewith.

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Preface

This is the first Engineering Doctorate (EngD) Conference hosted by the Industrial Doctorate Centre Technologies for Sustainable Built Environments (TSBE), University of Reading. It is the first of a series of annual EngD conferences that will be organised by the Centre for the Research Engineers (REs) to present their research findings to University academics as well as an industry audience. These proceedings include the abstracts of twelve papers which will be presented at the Conference and that of one paper which will be presented as a poster. The papers are prepared following the standard Conference format and have been reviewed by other academics in addition to the relevant supervisors. Each paper represents the current progress in the RE’s research project and a plan for continuing the research. The full papers will be published in an electronic format and distributed to the Conference delegates after the Conference. The aim of this Conference is to develop the REs technical presentation skills to expert audience, encourage debate and respond to critique and advice for developing the research to the next phase. It is hoped that these papers could then be developed for publication in international conference proceedings and learned journals in the relevant fields. I would like to express my gratitude to all those individuals who contributed to this Conference, without their dedication and enthusiasm it would not have been possible to hold this Conference. These include the REs who worked hard to prepare the papers after only a few months into their project work, the project supervisors (from the University and the sponsoring companies) who gave encouragement and support for their researchers, the academics who reviewed these papers, and for the sponsoring companies who initiated the research projects and provided support throughout. In addition, I would like to thank our two Keynote Speakers Professor Jeremy Watson, Arup and Gavin Walker, Peter Brett Associates, LLP for giving up their valuable time to participate in this Conference. My thanks also go to the Centre staff Jenny Berger and Emma Hawkins for their dedication and hard work in organising this Conference. Finally, I hope that all the participants will find this event stimulating and enjoyable. Professor Hazim Awbi Conference Chair TSBE Centre Director

University of Reading

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Key Note Speaker AM Professor Jeremy Watson, MSc DPhil CEng FIET FRSA Professor Jeremy Watson is Arup’s Global Research Director, responsible for Arup’s Research Strategy and the Research Consulting Business. In November 2009, Jeremy was appointed Chief Scientific Advisor to the Department of Communities and Local Government. Jeremy has held research and technical management roles in industry and academe including service with the DTI, DIUS and EPSRC. His specialities include Strategic Technology Development and Transfer, Innovation Processes and NPD Management. Jeremy is a Chartered Engineer, Fellow of the IET, Fellow of the Royal Society for the Arts, a Senior Member of the IEEE and Visiting Professor at the Universities of Southampton and Sussex. Jeremy is a Board member of the UK Government Technology Strategy Board, a founding member of the Institute for Sustainability, and a member of the HEFCE Research & Innovation Committee. In May 2010 Jeremy was appointed to the Board of the CIB. Technical & Business Challenges in Realising a Sustainable Built Environment Talk for TSBE EngD Conference, University of Reading, July 6th 2010 The drivers for achieving sustainability in the Built Environment are becoming well known; 45% of emitted CO2 is due to buildings with 27% of this from domestic homes. The need to mitigate anthropogenic climate change has motivated the introduction of UK legislation requiring an 80% operational carbon reduction by 2050 for both existing and new build. Closer deadlines of 2016 and 2019 set hurdles for zero carbon domestic and commercial new build. Also of vital importance are needs to adapt to both inevitable climate change and increasing energy costs. These enormous challenges, particularly of retrofitting ~22 million existing homes, has highlighted some key technical and business challenges for research and commercial communities. Within these challenges lie exciting opportunities for transformational research and positive economic outcomes. The talk will cover scope and dimensions of the challenge, key knowledge, method and competency gaps, and ways forward to help business understand needs and opportunities.

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Key Note Speaker PM

Mr Gavin Walker, BEng (Hons) CEng MIStructE MRSPH

Whitefield School champion, 200 metres

Gavin left school at 16 with 3 O levels. Armed with “Rotring” pens, a set square and stencils this trainee draughtsman spent his formative years on the drawing board and blessed with a boss who sent him to study the British climate down holes, up ladders, along scaffolding, and off to polytechnic. Ten years later he emerged as a Chartered Engineer with a desire to build, to influence, and to impact on the world.

Twenty years further on he is still yearning, learning, and practising the appliance of science as Director of the Built Environment at Peter Brett Associates, one of the UK's leading independent multi-disciplinary consultancy firms with a £40m turnover. He is now supported by a multi talented skills base with structural, civil, water, mechanical, electrical, geotechnical, transport, environmental, and hydrological planning and engineering teams. Academic training and the art of engineering has allowed Gavin to satisfy a thirst to make a difference and he intends to continue to do so for a while yet, starting today.

Don’t Shoot The Messenger – A Year in The Life of a Practitioner.

Talk for TSBE EngD Conference, University of Reading, July 6th 2010

Climate change has been described as the greatest long term challenge facing mankind today. The predicted time scale to irreversible change is short. Energy planning and implementation is in the midst of a revolution, and some have said we are at war.

This talk will describe the daily challenges addressed in a planning and engineering design office since 28th September 2009, the inauguration of the University of Reading TSBE centre. This will describe the state of play in the construction sector and review the opportunities both lost and gained. We may venture to propose improvements that could be made and our aspirations for the year ahead.

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Contents

Defining a Standard Carbon Cost Model for Electronic Software Distribution D. R. Williams

Adopting High Levels of Renewables: An International Perspective on Approaches M.L. Kubik

Vertical Axis Wind Turbines (VAWTs) in the Built Environment and Computational Fluid Dynamic (CFD) Simulations R. Nobile

Review of Domestic Hot Water Demand Calculation Methodologies and Their Suitability For Estimation of The Demand for Zero Carbon Houses. R. Burzynski

Sustainable Data Centres – Approaches and Challenges S. Luong

Aspects of a Sustainable Community Development Framework T. McGinley

Selecting Key Performance Indictors (KPIs) for Sustainable Intelligent Building H. Shah

Use of Soft Measures to Reduce Private Vehicle Use Among Commuters M. H. Ismail

Bats and Breathable Roofing Membranes: Mechanical Stability of Membranes under Bat Usage Conditions. S. Waring

The Carbon Life Cycle Of Buildings: A Review of the Current Carbon Emissions Reduction Strategy for Buildings. H. J. Darby

Introduction to Energy Use in Food Retail Spaces E. K. Mottram

Raising Energy Awareness in Refurbished Non-Domestic Buildings: Challenges and Opportunities M.M. Aghahossein

Abstracts for Posters

Study of Parameters Affecting Performance of Solar Photovoltaic (PV) Systems of Various Designs Operating in the Field P. Burgess

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Proceedings of Conference: TSBE EngD Conference, TSBE Centre, University of

Reading, Whiteknights Campus, RG6 6AF, 6th July 2010. http://www.reading.ac.uk/tsbe/

Defining a Standard Carbon Cost Model for Electronic Software

Distribution

D. R. Williams1*, D. Strange2, Y. Tang3

1Technologies for Sustainable Environments, University of Reading, UK 2Microsoft UK, Reading, UK

3Informatics Research Centre, University of Reading, UK

* Corresponding author: [email protected]

This paper focuses upon defining a method and set of parameters in order to

successfully calculate the environmental impact of Electronic Software Distribution

(ESD) when compared to its physical alternative. Little focus is given to the

environmental impact of this service due to its complexity. This model has

successfully identified parameters that can act as requirements for the calculation

of ESD impacts allowing comparable results to be calculated across many scenarios.

In a review of recent model methodologies and results on the impact of electronic

distribution, this paper surmises that a focus upon the data centres that serve the

hosting and fulfilment of an ESD service is of prime importance. Using three real

world scenarios and using the Life Cycle Analysis (LCA) methodology, methods of

calculating the carbon emissions have been developed. The development of this

model uses the PAS 2050 standard as guidance for model sections. This study

includes the carbon embedded within a server and its creation and transport, which

is a departure from the PAS 2050 methodology.

Keywords: Environment, Green IT, Software, Carbon, Service.

ABSTRACT

This paper focuses upon defining a method and set of parameters in order to

successfully calculate the environmental impact of Electronic Software Distribution

(ESD) when compared to its physical alternative. Little focus is given to the

environmental impact of this service due to its complexity. This model has

successfully identified parameters that can act as requirements for the calculation

of ESD impacts allowing comparable results to be calculated across many scenarios.

In a review of recent model methodologies and results on the impact of electronic

distribution, this paper surmises that a focus upon the data centres that serve the

hosting and fulfilment of an ESD service is of prime importance. Using three real

world scenarios and using the Life Cycle Analysis (LCA) methodology, methods of

http://www.reading.ac.uk/tsbe/

mailto:[email protected]

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calculating the carbon emissions have been developed. The development of this

model uses the PAS 2050 standard as guidance for model sections. This study

includes the carbon embedded within a server and its creation and transport, which

is a departure from the PAS 2050 methodology.

Keywords: Environment, Green IT, Software, Carbon, Service.

1. INTRODUCTION

Quantifying environmental impacts that result from changes in lifestyles,

paradigms and human activities is essential to aid businesses and individuals plan

and understand what difference their changes will make. This paper focuses upon

developing a method to calculate the environmental impact of Electronic Software

Distribution (ESD). ESD is a service by which a digital program is transmitted over a

computer network, such as the World Wide Web, to a consumer.

Measuring the impact of ESD over its physical alternative is often difficult and

complex as Abukhader and Jönson (2003) submit in a review of previous studies

conducted up to 2003. Past studies have indicated that electronic distribution could

benefit the environment if the correct hardware and software infrastructures are

setup. All previous studies concluded that the variance in model results is too large,

and that it is difficult to measure the exact impact; Weber et al. (2009), Seetharam et

al. (2010) Moberg et al. (2008) and Toffel and Horvath (2004) have all completed

recent similar studies in different e-commerce areas. WSP (2007) & WSP &

Accenture (2009) have completed models directly applicable to ESD. These models

found large benefits of using ESD over physical distribution (~90% savings) and will

be used as foundations for this investigations model.

The Carbon Trust (2010) created a Life-cycle assessment (LCA) model that is used to

calculate carbon footprints of various products. This tool has no option to calculate

ESD, however the models equations, principles, databases and design are the result

of continuous improvement and ratification with academic consultants. This model

will therefore be used as a guide.

The lack of academic attention in this area means that commercial solutions have

been created which do not undergo the rigour of academic review and

improvement and can be subject to scenario specific conditions and assumed

parameters. Modelling any process is difficult as Gard and Keoleain (2003)

demonstrated in a LCA of a digital and traditional library that highlighted how

sensitive modelling parameters are, and how they can wildly influence results. This

investigation aims to create a model foundation that can be used in many scenarios

that use ESD and will aim to identify key model parameters to focus upon when

calculating impacts of ESD compared to physical distribution.

The key objectives of the overall investigation are to create and assess a

methodology to measure the carbon emissions for three online service scenarios

and to identify key focus areas for an ESD model. The first of a user purchasing and

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downloading a software package from an online store, secondly the user purchasing

via an online store but getting sent the package and finally the user purchasing

online, downloading the software and getting sent a backup DVD disk.

2. BACKGROUND

Many studies on the environmental impact of transmitting bits instead of moving

atoms have been completed since the invention of modern computer systems.

During the past 10 years many studies on digital downloads have been completed,

and the following studies are those that will be analysed as they share

commonalties with the ESD scenarios being analysed.

The inclusion of different download scenarios is important when assessing overall

impact of ESD to physical alternatives. A large result variance was found by Weber

et al. (2009) who analysed the impact of delivering music via the internet or

purchasing a CD from a retail store using a LCA methodology using many scenarios.

The study performed a full life cycle analysis and showed a potential cut in CO2

emissions of between 40-80% when the download option was used. A limitation of

their study was due to the lack of equivalence found between downloading a CD

and purchasing a CD. This investigation differs however as software and purchasing

software can be safely assumed in this situation as software does not contain album

artwork and in many cases the software media is used only once in its lifetime. This

limitation would however be assumed when focusing upon gaming software.

Different hardware setups and power saving technologies can swing a carbon

footprints value by 270%, therefore this study will place a large emphasis on

understanding what hardware technologies are being utilised. This issue was

demonstrated by Seetharam et al. (2010) where an LCA investigation discovered the

differences in shipping a DVD movie to a consumer as opposed to streaming a DVD

over the internet. It was found that currently the CO2 impact of streaming would be

205% higher than standard shipping but with future improvements in hardware,

the footprint could be 65% less than shipping. The model assumed many values and

parameters throughout but also highlighted the efficiencies that can be gained over

electronic distribution when the file size is very large (> 8GB).

Many methods of calculating internet transfer usage exist. Moberg et al. (2008)

performed a study on changing Sweden’s financial invoicing system from paper to

digital platforms. This study implemented innovative ways of calculating internet

transfer usage and is useful to compare against as its results on internet usage are

current and unlike other studies. Moberg et al. (2007) showed how using different

technologies to read a newspaper can also dramatically change the environmental

impact, highlighting again that the hardware being used is important in the

calculation methodology.

WSP, a respected US based worldwide environmental consultancy performed two

key studies to this investigation. The first was an evaluation of how ESD via the

internet is different from a user purchasing a hard copy of Microsoft Office 2007

from a store (WSP, 2007). This study attempted to follow the PAS 2050 LCA

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methodology (see Section 3) and resulted in the download scenario avoiding 93% of

emissions. WSP & Accenture (2009) conducted a similar study comparing the

benefits of distributing Microsoft software to its Volume Licence customers (large

enterprise software packages) via ESD compared to the traditional route of sending

software via the post. The reduction in CO2 emissions was found to be 91% and as

previously discovered the distribution section for the digital download scenario

contained over 90% of the overall footprint. Table 1 highlights the areas covered

and results from the 2007 study. As found in previous studies, for digital download’s

the distribution (via servers) of the software is the largest area of importance to

focus upon.

Table 1 - Results from WSP (2007) study comparing ESD and Purchased product scenarios for Microsoft Office 2007.

Digital Download kgCO2eq

Full Package Product kgCO2eq

Avoided Emissions kgCO2eq

Materials 0.02 1.09 -1.06 Distribution Process 0.47 6.37 -5.90 End of Life 0.00 -0.60 -0.60

Total Emissions 0.50 6.86 -6.36

From the WSP & Accenture studies the largest source of emissions result from the

digital distribution process. It is therefore apparent that the most important area to

focus upon when analysing ESD is the data centre’s power consumption which

includes servers and associated cooling, storage and networking equipment.

Calculating this section is difficult as the power used by a data centre and its

associated modems, routers, hubs, switches and internet backbones is difficult due

to the variety and variability of hardware specifications and software used to run

them.

The detailed makeup of a data centre is often a guarded company secret and thus

assumptions on the server hardware and associated networking equipment are

often used. Koomey (2008) provides a brief history of data centre power calculation

studies completed and Koomey (2007, 2008) performed in depth analysis and

derived average power consumption values for the world, world region and by

server class (Table 2). This study used publicly available server data from server

manufacturers to determine server power usage using basic industry recognised

assumptions. The server calculation methodology from this paper can be applied to

any data centre setting and thus provides a good foundation to understand current

power consumptions. This methodology, however, excluded the power consumed

by data centre data storage and networking equipment and related cooling and

auxiliaries, which is of prime importance when providing a user with software

stored within a server base. Roth (2002) includes a method to calculate the data

storage and the US Environmental Protection Agency estimated power used by data

storage and networking equipment (EPA, 2007), which can both be used in this

study as good foundations.

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Table 2 - Average power consumption per server type from 2000 to 2005. (Koomey, 2008)

Average power used per server (World)

Units Volume Mid-Range High-end Average

2000 Watts/Server 183 423 4874 236 2005 Watts/Server 222 607 8106 257

The Power Usage Effectiveness (PUE) (aka Site Infrastructure Energy Overhead

Multiplier (SI-EOM)) is an industry standard measure to determine how energy

efficient a data centre is. The PUE is calculated as a ratio by dividing the amount of

power entering the data centre complex by the power used to run the servers and

computers of the datacentre thus the smaller the PUE the more efficient the data

centre. The PUE has become an IT marketing tool for many companies with

Microsoft quoting a PUE of 1.25 at their Dublin datacentre (Microsoft, 2009) and

Google claiming a monthly PUE of 1.10 for one facility (Google, 2010). The PUE can

thus be determined for a data centre and applied to the power consumed by servers

and storage equipment to work out the cooling and auxiliary power demands. The

PUE has been used in WSP (2007) and WSP & Accenture (2009) as a way to simplify

the model, this technique will be used in this model also.

Virtualisation refers to the technique whereby more than one server session can be

run on one physical server in unison. A server without virtualisation will run at

about 40-60% efficiency (Koomey, 2007) thus virtualised systems use a physical

server’s hardware more efficiently as more is being completed. Measuring is very

difficult as virtualisation techniques mean that the amount of virtualised servers

vary with demand. Little academic work has been completed in this realm however

Abaza et al. (2009) provides a good technique to work out maximum potentials

based upon server hardware. The amount of virtualisation is thus another

indication of how efficient a server is and thus needs to be factored into the model;

this is something not covered by previous studies.

3. METHODOLOGY & DATA

To assess the three scenarios and to identify the key parameters, LCA methodology

will be utilised. LCA is an established technique to analyse a product from its

creation to its end of useful life (Finnveden, 2010). PAS 2050 LCA requirements will

be adhered to and the principles of creating a model that can be used in many

situations to allow users to compare results will be a key model design feature. PAS

2050 was drawn up by the Carbon Trust and Defra and is an internationally

recognised specification for the assessment of the life cycle greenhouse gas

emissions of goods and services and specifies basic requirements for an LCA. This

requirement specification means that organisations can undertake an LCA and

compare it to a competitor or alternative product knowing exactly what to take into

account and what to leave out, i.e. the boundaries are pre-set making the overall

LCA process simpler and less time consuming.

To begin creating the model structure, each scenario must first be understood. Each

scenario was detailed by analysing the processes of the online store of a large

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software company. This analysis involved many interviews and worldwide

communications to fully understand what occurs during digital and physical

distribution as well as the website hosting stage. The resulting process maps were

placed into a functional flow chart following the LCA methodology of splitting the

sections into five key stages; raw material extraction, manufacturing and

production, distribution and transportation, operations and maintenance and

disposal and recycling

The resultant process maps were then analysed and the principle rules of PAS 2050

were applied to identify the scope of the subsequent LCA. Using models from WSP

(2007, 2009) and from the Carbon Trust (2010) as section examples the filtered

process maps were split into sensible sections and placed onto a spread sheet.

Each section of the overall process was detailed to include its main inputs and

outputs. The equations used for each sections input and/or output calculation were

a combination of WSP (2007, 2009), Carbon Trust (2010) and Weber (2009); each was

analysed and modified when appropriate. For each calculation, an emission factor is

used to relate that process to a CO2 equivalent value. Many emission factors exist,

however the Carbon Trust (2010) produces a list of PAS 2050 certified emission

factors or lists PAS2050 certified calculation sources and methods. This certified list

was used to produce a list of emission factors relevant to the study. PAS 2050 factors

are used as they include ‘cradle to grave’ emissions thus simplifying the overall

model as details about processing energy from each stage is not needed.

4. INITIAL RESULTS

Figures 1 & 2 describe the sections of each scenario that were taken into account

within the model.

Figure 1 describes the processes that all scenarios share; when the user uses their

computer and logs onto an online store to purchase software. The transfer of

information over the internet for this process is assumed to be comparatively small

therefore it is excluded however the time that the user spends using their computer

is accounted for. The data centre that hosts the website and fulfils the download is

accounted for in terms of both energy and components. It is contentious to include

the embedded energy for servers in this section as it may contravene PAS 2050

rules. This was included as the data sent to and from a user cannot reach a user’s

computer in any other way and servers, although highly variable, are standard

enough in design to assume components and construction methods. Following PAS

2050 guidelines to not include embedded energy, the user’s actual computer system

is not accounted for in the model. This is because unlike servers a website could be

accessed in a number of different ways, PC, MAC, Phone, Laptop etc. The Digital

Distribution route for a user to download from the online store is also included in

Figure 1. Commonly online stores will use a different server and data centre to

fulfil downloads and thus in this scenario an additional data centre is accounted for

using the same calculation method as digital purchasing. This process includes a

calculation of internet transfer as the software sent is assumed to be of a size that

could impact on carbon emissions.

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Figure 2 highlights physical distribution for a software item. This section comprises

a standard LCA and thus this section takes into account the software packaging and

raw materials, associated transport, final distribution and end of life calculation.

The results of this section follow the results of the WSP (2007, 2009) study closely. A

large amount of detail is required for this section.

Using the process maps an initial model was calculated. From an initial set of

results ~42% of the overall emissions for digital distribution only come from the

server fulfilment stage (power usage). The following model parameters were

identified as important to calculate this section (and thus the server hosting section

also);

Server Plate Ratings and Observed Server Power for each server being used

Virtualisation Ratio per server (i.e. The server may host 10 virtual servers)

The amount of virtual server sessions per measured process (i.e. The online store may use 5 of the 10 virtual servers)

Percentage of the process being used by the measured activity (i.e. The download activity may be using on a certain percentage of the server session)

The time of the activity being measured

The size overall data being transmitted

The Network Equipment Ratio for the data centre in question

Number of times the measured process is performed (i.e. The process may be interrupted and restarted)

Data centre PUE

For digital distribution, internet transfer accounted for only ~1% of total emissions

and the user download and user purchasing together accounted for ~5% of the total.

Materials and associated transport and end of life for the servers accounted for ~10%

of total emissions.

For the physical distribution model, ~65% of total emissions come from the material

stage and 15% coming from the online stores server hosting stage. Distribution and

End of Life sections accounted for ~8% and 9% respectively. For this section

important parameters to focus upon are the materials section which needs to

include a detailed inventory of the packing type and related items such as booklets

and the amount of DVD’s sent. Like digital distribution, understanding the

parameters of the hosting server is also important for this section.

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Online Store – Digital Purchasing & Digital Distribution (Scenario 1,2 & 3)

ManufactureRaw Materials Distribution End of Life

Raw Material Sourcing, extraction

& processing

Transportation

Server & IT Equipment Materials

Manufacture

Transportation

Data Storage and Networking Equipment

Data Centre IT Equipment Materials

Hosting Server

User Purchasing*

Data Centre Cooling and Auxiliaries

Postage DownloadDownload with

backup

Fullfilement Server

Internet Transportation

User Download

* This section falls under the Operational section of the LCA

Figure 1 – The use of the online hosting server is common to all scenarios and involves the user spending time online whilst purchasing the software. When the user selects the download only or download with backup scenario, the use of the fulfilment server and the internet transfer to the user are taken into account.

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Online Store – Physical Distribution (Scenario 2 Only)

ManufactureRaw Materials Distribution End of Life

Material Landfill & Recylcing

Extraction, processing and

transport

Manufacture of base Materials

Transport

Packaging (Plastic & Cardboard)

Printed Materials

Labels

DVD & DVD Pressing

Package Assembly

Distribution Centre(Regional)

Transport

Transport

Transport

Distribution Centre(Regional)

Figure 2 -- If the user selects physical distribution (Scenario 2) then segements will be calculated which include the packaging and raw materials for the DVD box and the DVD itself.

5. DISCUSSION

From the background literature, previous models and this studies initial models

result, it is clear that the most important parameters for all scenarios modelled are

those involved with the hosting and fulfilment server sections. This result is not

ideal as gaining information on data centre setups is very difficult and thus limits

the models usability within the wider community. However, the results of the

initial model suggest that when focusing upon digital distribution assumptions

about internet transfer can be made as the total impact on the overall footprint are

relatively low compared to the data centres use. This is positive as attempting to

predict the path way of data across a network (i.e. from the UK to the USA) and

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determining the proportion of the network that the process is using would be a

difficult process to complete.

From the set of model parameters highlighted as important to calculating server

emissions for an activity running on a process, it is obvious that measuring this is

going to be a difficult task. Many data centres include process monitors and

standard assumptions can be made however, further work needs to be completed in

measuring and reporting process usage by servers in order to hone results.

This framework for the calculation of ESD sets out an academic solution to a

problem only partly attempted by software companies (WSP 2007, 2009). This

model has taken best practice and industry solutions to provide an independent

analysis of the area’s most likely to produce the largest emissions and provides a

requirement specification for physical distribution that allows comparisons to be

drawn to ESD. Including sections on virtualisation and the actual utilisation of the

server for a specific ESD process is a new feature and will allow the implementation

of energy saving technologies to improve the carbon impact from a server and thus

lessen impacts over time. However, important assumed areas such as PUE values

must now be studied and verified if the model is to be utilised and developed.

The next step in this investigation will be to use real world data on the model and

attempt to test the models outputs against actual emission outputs to gauge how

successful the model has been. The model will is also being reviewed by PAS 2050

consultants and will be adjusted appropriately for eventual use in the wider

community.

6. REFERENCES

Abaza, M. and Allenby, D. (2009). The effect of machine virtualization on the environmental

impact of desktop environments. The Online Journal on Electronics and Electrical Engineering,

1(1):49-51.

Abukhader, S. M. and Jönson, G. (2003). The environmental implications of electronic commerce:

A critical review and framework for future investigation. Management of Environmental

Quality: An International Journal, 14(4):460-476.

BSI (2008) PAS 2050:2008 Specification for the assessment of the life cycle greenhouse gas emissions of goods

and services. [Online]. Available: www.carbon-label.co.uk

Carbon Trust (2010) Carbon Expert Tool. [Online]. Available: www.carbontrust.co.uk

EPA (Environmental Protection Agency). (2007). Report to congress on server and data center

energy efficiency. public law 109-431. Technical report, US EPA, ENERGY STAR Program.

Finnveden, G. (2010). Life cycle assessment. [Online]. Available:

www.eoearth.org/article/Life_cycle_assessment

Gard, D. L. and Keoleian, G. A. (2002). Digital versus print: Energy performance in the selection

and use of scholarly journals. Journal of Industrial Ecology, 6(2):115-132.

Google (2010) Data Center Efficiency Measurements. [Online]. Available:

www.google.com/corporate/green/datacenters/measuring.html

Koomey, J. G. (2007). Estimating total power consumption by servers in the u.s. and the world. [Online].

Available: www.swisscom.ch/NR-IT/NR/rdonlyres/FF3B4BA3-7FF0-4BC8-9FD1-

20F8063BA991/0/green_it.pdf

Koomey, J. G. (2008). Worldwide electricity used in data centers. Environmental Research Letters,

3(3):034008+.

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Microsoft (2009) Greening the Dublin data center. [Online]. Available:

www.microsoft.com/environment/

Moberg, Ã., Johansson, M., Finnveden, G., and Jonsson, A. (2007). Screening environmental life

cycle assessment of printed, web based and tablet e-paper newspaper. Technical report,

Centre for Sustainable Communications, Sweden.

Moberg, Ã., Borggren, C., Finnveden, G., and Tyskeng, S. (2008). Effects of a total change from

paper invoicing to electronic invoicing in Sweden. Technical report, KTH Centre for

Sustainable Communications, Stockholm.

Roth, K. W., Goldstein, F., and Kleinman, J. (2002). Energy consumption by office and

telecommunications equipment in commercial buildings volume i: Energy consumption

baseline. Technical report, US Department of Energy.

Seetharam, A., Somasundaram, M., Towsley, D., Kurose, J., and Shenoy, P. (2010). Shipping to

streaming: Is this shift green? In Proc. of First ACM SIGCOMM Workshop on Green Networking.

Toffel, M. W. and Horvath, A. (2004). Environmental implications of wireless technologies: news

delivery and business meetings. Environmental Science & Technology, 38(11):2961-2970.

Weber, C., Koomey, J. G., Matthews, S. (2009). The Energy and Climate Change Impacts of Different

Music Delivery Methods. [Online]. Available: www.intel.com/pressroom/kits/ecotech

WSP (2007). Calculating business value and environmental benefit of digital software

distribution. Technical report, WSP.

WSP & Accenture (2009) Demonstrating the Benefits of Electronic Software Distribution: A study

of greenhouse gas emissions reduction. Technical report, WSP & Accenture.

Keywords:

Environment, Green IT, Software, Carbon, Service.

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Adopting high levels of renewable electricity: an international perspective on approaches

M. L. Kubik1*, P. J. Coker2 and C. Hunt3

1 Technologies for Sustainable Built Environments, University of Reading, United Kingdom

2 School of Construction Management and Engineering, University of Reading, United Kingdom

3 AES, Richmond upon Thames, United Kingdom

* Corresponding author: [email protected] ABSTRACT A significant contribution to meeting greenhouse gas (GHG) reduction targets in Europe is anticipated to come from renewable electricity generation. Some countries, such as Spain, Germany and Denmark are particularly advanced in this respect. Others, such as Ireland, have a significant renewable resource and have set ambitious renewable targets for the future, but currently only have small amounts of renewable generation capacity installed. This poses a question: what can be learnt from maturing renewables markets for developing markets like Ireland? This paper reviews the progress of Spain, Germany and Denmark in developing their renewable capacity, commenting on their current status, electricity market structures, policy approaches and expected future developments. Particular focus is given to wind, as this is currently seen as the most mature renewable technology and is likely to make up the bulk of renewable capacity installed over the next decade. Using this established background, Ireland is compared with Spain, Germany and Denmark, and important similarities and differences between these markets are established. Keywords: Renewable energy, variability, Europe, electricity market

1. INTRODUCTION

In recent years, the worldwide renewables sector has seen substantial growth emerge from a mounting global consensus on the threat of climate change; annual renewable energy investment, for example, increased fourfold to reach US$120 billion between 2004 and 2008 (REN21 2009). The European Parliament passed a binding climate and energy package in December 2008, requiring EU member states to commit to supply 20% of EU energy consumption with renewable resources by 2020 (European Commission 2010). In addition to combating climate change, the measure is intended to increase the EU’s energy security while strengthening its competitiveness on the world stage.


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Table 3 - Summary of countries considered

Country Population

Annual net electricity consumption (TWh), % from renewables

Installed Wind (GW), % wind penetration

Spain 47.0m 262.4 (22.1%) 19.1 (14.5%) Germany 81.8m 547.3 (16.5%) 25.8 (7.0%) Denmark 5.5m 35.8 (29.3%) 3.5 (20.0%)

Ireland 4.5m 25.1 (11.9%) 1.2 (4.0%) As indicated by Table 1, Germany and Spain are world leaders in their cumulative volume of installed wind energy capacity, behind only United States and China, and lead the EU league table by a considerable margin (GWEC 2010). Denmark on the other hand, has one of the highest wind penetrations in the world, and has experience meeting demand using variable output generation without compromising energy security. Each of these markets has developed uniquely, evolved from different policies and different drivers. Understanding these backgrounds can provide valuable lessons for policy design and market development, and is important to understand these different drivers when attempting to compare studies carried out in different markets. The approaches of Spain, Germany and Denmark were chosen partly for their respective advances in renewable energy integration, but also because they are commonly bound to Ireland by EU directives concerning rules for driving competitive markets (e.g. Directive 2003/54/EC). The UK market status and policy arrangements are not explicitly studied in this paper, but they do come into the discussion with respect to energy policy in Northern Ireland. Ireland1 has a significant renewable resource and has set ambitious renewable targets for 2020, but to date has only relatively small amounts of renewable generation capacity installed. It is well placed to learn from the developments in Spain, Germany and Denmark, as it is expected to follow a similar surge in growth. This paper examines each of these markets in turn, highlighting their current status and their progress in integrating renewable energy, and comparing this contextually to Ireland. The general market structure and the policy incentives they have adopted are also identified, followed by suggestions of expected future progress. Particular focus is given to wind, as this is currently seen as the most mature renewable technology and is the target of the bulk of research. However, many of the concepts that apply to wind integration, for example, grid connection costs, apply equally to other forms of variable output renewable energy.

2. SPAIN

2.1. Market status

Spain is ranked as the world’s fourth largest wind energy market, with an installed capacity of 19.1GW supplying 14.5% of the country’s annual electricity demand in 2009 (GWEC 2010). A recent study suggests that the Spanish wind energy sector contributes more to GDP than other key Spanish industries such as fisheries or

1 Ireland in this paper refers to the whole island of Ireland (i.e. the Republic of Ireland and Northern

Ireland combined) as they share a common electricity market. Where statistics refer to the ROI or NI

specifically, this is clearly identified in the text.

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wine (Deloitte 2009). Furthermore, Spain is also ranked second in the world for installed PV, contributing 3.3GW of the world total of 13GW in the latest 2008 estimates (REN21 2009). Though European guidelines and legislation have played a role in Spain’s renewable energy development, there was also early internal acknowledgement of the socioeconomic and environmental benefits by the Spanish government, and renewable energy promotion has been a national policy priority for over a decade. A detailed energy plan was produced in 1999, together with the introduction of a flexible feed-in tariff (Sáenz de Miera et al. 2008), where renewable generators are paid a guaranteed and favourable price for some or all of the energy they supply. Spain’s wind integration has also been aided by a number of technical innovations. For example, the establishment of a centralised Control Centre of Renewable Energies (CECRE), which allows the system operator (SO) to curtail wind generation in real time, to reduce the problem of excessive generation (Ofgem 2010, pp.39-40).

2.2. Market structure and policy

Spanish electricity trading consists of a number of markets2: the day-ahead market, an intra-day market consisting of six intraday trading periods, and an ancillary services market, where balancing services and reserves are traded to ensure system reliability against unplanned deviations from scheduled generation or forecast demand. Participation in these markets is optional, as participants are instead allowed to enter physical bilateral contracts for trading electricity. The Market Operator (OMEL) is responsible for constructing a merit order dispatch (selecting the most cost effective plant to meet predicted demand using optimisation software), based upon generator supply bids and demand information from retailers. The System Operator (REE) studies the feasibility of the merit dispatch and modifies it to deal with any practical constraints. Units used to solve the transmission constraints are paid their original bid, whereas the units which are displaced from the dispatch do not receive any payment at all. Though a liberalised energy market, Spain is dominated by a small number of large utilities, such as Endesa and Iberdrola. In 2006 these utilities produced 25.3% and 20.5% of total consumed electricity respectively (Conejo 2007). Spain is also rather isolated, with little interconnection with France and the rest of Europe.

The costs of renewable generation are accounted for in the annual calculation of the electricity price, thereby ensuring that the additional cost to consumers is proportional to their electricity consumption (GWEC 2010). Renewable generators in Spain are granted priority grid access and priority feed-in. There is a choice of two policy support mechanisms, which renewable generators may switch between freely every 12 months.

a) A technology specific fixed feed-in tariff b) A technology specific fixed feed-in premium, on top of the fluctuating

wholesale electricity market price.

The scheme was originally introduced in 1998, but has undergone several revisions by Royal Decree, including the introduction of an upper and lower limit to revenue from the feed-in premium (Klessmann et al. 2008). Under option (a), renewable

2 For a fuller description of the Spanish market structure, see Crampes & Fabra (2004).

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generators are not exposed to market prices and are under only limited balancing obligation3. Under (b), participants are fully responsible for balancing and must pay for any deviation from their forecasted schedule. Imbalance prices are also capped for all generators in Spain, and dual imbalance pricing is used. A high charge is applied for deviations from the schedule that increase overall system imbalance and a zero charge for those that reduce it (Klessmann et al. 2008).

Renewables receive guaranteed grid access in Spain. Any distribution level connection costs are paid in full by the developer, and a negotiable component of any transmission costs where necessary. These negotiations are seen as “a major obstacle in the grid connection process” (Klessmann et al. 2008, p.3652), as it is often unclear what transmission reinforcement would be necessary without the connection of a renewables project. The Transmission System Operator (TSO) tends to pay the majority of the cost, with around 20% paid by the developer.

2.3. Future developments and challenges

The Spanish Renewable Energies Action Plan is currently being drafted for the period of 2011-2020, which will set out the targets for each of the renewable technologies over the course of this period. Though still subject to change, it is forecast that the contribution by renewable energies to gross electrical generation in 2020 will be 42.3% of demand (La Moncloa 2010). Grid demand in Spain is growing fast, but network reinforcement is slow due to long negotiations and ambiguity over who should pay for transmission reinforcement. Network congestion is hence likely to be a future barrier to renewable development. 3. GERMANY

3.1. Market status

Germany remained the market leader in European wind capacity at the end of 2009, with 25.8GW of wind installed supplying 7% of net annual consumption (GWEC 2010). Germany also leads the world in installed PV capacity, with 5.4GW installed at the end of 2008 (REN21 2009). At 547TWh, electricity consumption in Germany was the highest in Europe in 2007, with the combined total of all installed renewable technologies (including also hydro, geothermal and waste combustion) supplying 16.5% of this consumption (EIA 2008). The renewables industry in Germany was estimated to have created 235,000 jobs by 2006 (BMU 2007), and this number is expected to have risen still further in the past few years based upon continual renewable sector growth.


The German market was liberalised in 1998, with significant restructuring and intense price competition that led to mergers and acquisitions. Today, only four major players remain; Vattenfall, E.ON, RWE and EnBW. Unusually for Europe, the German transmission grids are owned and operated by these four major utilities, rather than a state-owned entity. They each function as TSO for their region and

3 All generators operate to a schedule, and are expected to deliver any electricity they have agreed to

produce. Normally, any unplanned deviation from this schedule has an associated imbalance penalty.

For renewables under option (a) a technology specific tolerance applies to deviations from the generator’s

forecast schedule (e.g. for wind and solar any deviation of ±20% from the forecast begins to incur a

balancing charge per MWh).

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are responsible for balancing and scheduling. The generators and retailers from all regions are all participants of the European Energy Exchange (EEX), Germany’s wholesale electricity spot market. This consists of a day-ahead market and intra-day trading with Austria, France and Switzerland.

A simplistic single tariff feed-in law was passed in the form of the Electricity Feed Act (StrEG) in 1991 (Wüstenhagen & Bilharz 2006). In 2000, the Renewable Energy Sources (EEG) act was introduced to replace StrEG; guaranteeing priority grid connection and access for renewables and a technology and site specific tariff that can last for up to 20 years (Büsgen & Dürrschmidt 2009). It was later amended in 2004 and 2009, the latter with new higher rate tariffs to stimulate market growth. Under the feed-in tariff, renewable generators do not participate in market trading, nor are they responsible for balancing. Their electricity is given priority and sold at a fixed price. The TSOs take the responsibility for forecasting, scheduling and balancing. Klessmann et al. (2008) also refer to a responsibility to transform fluctuating renewable load profiles into a standard load profile. The financial implications of this are supervised by the regulator (Bundesnetzagentur) and the costs are passed on to the customers via a Use of System Charge (UoSC). The TSOs claim to provide these services competitively, but in reality this process is not transparent. As transformation costs are passed on, there is no direct incentive to reduce them. The regulator has challenged transformation pricing in the past (Klessmann et al. 2008).

Renewable generators in Germany only have to pay for connection to the nearest grid connection point. Unlike Spain, all necessary network reinforcement costs are carried by the TSO, who again pass the costs along via the UoSC. Currently, all new renewable installations have to be equipped with technical provisions for curtailing output, to ease the burden on transmission constraints in exceptional generation situations (Swider et al. 2008). Renewables curtailed in this manner would currently not receive any compensation for loss of production. Though currently rare, as renewable penetration levels rise and over-generation events become more likely, this will become an increasingly problematic occurrence.


The German government’s electricity sector target for 2020 is 30% of generation to come from renewables (GWEC 2010). However, the German Renewable Energy Association has forecast that by 2020 the quantity of power coming from renewables will be 47% of gross production, including 25% coming from wind (BEE 2009). The current conservative/liberal government has announced that it is reconsidering proposals put in place by the earlier social democrat/green coalition to phase out nuclear power, and plans to publish a new energy concept in autumn 2010, mapping their pathway to a 100% zero carbon energy supply (GWEC 2010).

Similar to Spain, transmission line reinforcement grows slowly relative to the number of new generators seeking connection. An existing “repowering bonus” for replacing turbines over ten years old with turbines at least double their capacity is expected to become increasingly relevant in the coming years. By 2015 more than 6GW of operating turbines will be more than 15 years old; repowering is expected to have a significant renewal influence on these.

Finally, a concerted effort to increase offshore renewable projects is to be made, with connection lines for offshore clusters to begin construction. The government

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have given developers additional incentive to invest by increasing the feed-in tariff and minimising grid connection costs (Swider et al. 2008).

4. DENMARK

4.1. Market status

Denmark supports a much smaller population than Germany and Spain (see Table 1), and has much lower gross annual consumption; 35.8TWh compared to 547.3TWh and 262.4TWh respectively (EIA 2008). It had 3.5GW of installed wind at the end of 2009, supplying around 20% of annual electricity demand. Past Danish policy has promoted home insulation and seen significant growth in the use of distributed CHP. The Danish Energy Agency estimates that 55.4% of thermal electricity production was generated in combination with heat during 2008 (DEA 2009). Consequently Denmark is leading in terms of integrating distributed production into the national electricity production system (Lund 2005).

The Danish government banned the construction of nuclear power stations in 1988, following the Chernobyl disaster, and introduced legislation to aid the promotion of renewable energy. Wind today is one of Denmark’s largest export industries, and is projected to become their largest industry in terms of turnover in 2010. Danish wind manufacturers Siemens and Vestas accounted for almost 90% of Europe’s new installed offshore capacity in 2009. Employment in the wind sector was estimated to be 28,400 in 2008 (GWEC 2010).


The Danish electricity market is part of the Nordic wholesale electricity market or “Nord Pool”, consisting of four interconnected Nordic countries (Denmark, Sweden, Finland and Norway) and regulated by NordREG. The market was fully liberalised in 2003 and hence exposed electricity trading and production to competition. It consists of two parts: “Nord Pool ASA”, a forward market, and “Nord Pool Spot AS”, which operates a physical day-ahead spot market (Elspot) and an intra-day balancing market (Elbas). In Denmark, between 60-90% of electricity is traded in Nord Pool (Kristiansen 2007).

The Danish TSO (Energinet.dk) sends power bids on behalf of participants to the Nord Pool Spot market in Oslo. A ‘coordinator’ then compiles a joint list of all power bids in the Nordic countries, sorted by price, and an unconstrained system price is calculated one day ahead of dispatch (Kristiansen 2007). System constraints are applied to this single system price to determine a local price for each price area (of which there are two in Denmark: DK1 and DK2). There are significant advantages to the flexibility of this interconnected system. It allows Denmark access to secure energy when renewable energy output is low, and can sell output when renewable supply outstrips demand. However, prices in the Nord Pool can be volatile; they are strongly dependant on the reservoir content of hydrosystems in Sweden and Norway and the level of wind generation in Denmark.

Renewable energy in Denmark was first actively encouraged in 1990 (a second plan was produced in 1996), with a Danish energy plan setting targets for wind installation and a supporting feed-in tariff. In 1999, an Energy Act was passed which planned a transition from the feed-in model to a quota based tradable green certificate (TGC) market, similar to that adopted in the UK. The reason for this shift was an expectation that the TGC model would be made standard at an EU level, and

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that the feed-in model that Germany introduced would not be allowed. It turned out that negotiations reached a compromise that allowed the continuation of present national models (Meyer 2003) and this led to policy uncertainty for a number of years in Denmark. Danish feed-in tariffs were reduced substantially for wind in 2002, and the market stalled until 2008, when a new support framework was introduced (GWEC 2010). The current policy mechanism for wind is a feed-in premium scheme, with an additional compensation for balancing costs. All other renewable technologies remain supported by feed-in tariffs.

The 1999 energy bill sets out the rules on grid connection charges. Renewable generators only have to pay the costs covering connection to the nearest grid connection point. The costs for grid reinforcement are met by the distribution system operator (DSO) and the TSO as with Germany. For offshore developments, the connection charges are shared among all electricity consumers, again similar to Germany (Scott 2007).


The Danish government established a dedicated Ministry for Climate Change and Energy and new energy strategy in 2007 (‘A visionary Danish energy policy’). This targets 30% of total energy (i.e. not just electricity) consumption to be supplied with renewables by 2025. This is expected to require a 50% wind penetration on the grid system.

There is an expectation that future development of renewables in Denmark will focus on large offshore projects which are currently in planning (IEA 2009). Another aspect of development is the government’s repowering scheme, introduced in 2005. As with Germany, this is to replace turbines over a certain age with larger capacities, the uptake of this scheme is expected to grow in the coming years.

5. COMPARISONS WITH IRELAND

5.1. Market status, future developments and challenges

Ireland has one of the smallest electricity markets in the EU (25.1TWh), but it possesses some of the best renewable energy resources in Europe, with an “exceptional” wind resource (four times the European average), “excellent” wave resource and “significant” tidal energy (Rourke et al. 2009). In 2008 renewable generation accounted for 11.9% of total annual electricity consumption in the Republic of Ireland (ROI), with 1,161MW of installed wind. Total energy use in 2008 was 96% dependant on fossil fuels, with 89% of this energy coming from net imports (Howley et al. 2009).

Compared to Spain, Germany and Denmark, Ireland is a long way behind in terms of installed capacity and in renewable penetration. However, both the ROI and Northern Ireland (NI) governments have set ambitious 2020 targets for decarbonising their electricity supply: 40% of electricity consumption to be supplied by renewable resources in the ROI; and 30% from renewables in the UK, with a further 10% expected to be met by nuclear. A significant proportion of this is anticipated to come from wind. These targets exceed the progress made over the past 20 years by Denmark in reaching a 20% penetration level for wind, and will require strong governmental support and rapid growth of renewable generation in Ireland. However, Ireland has the advantage of being able to learn from best practice from other countries, to take advantage of technology improvements, and

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the falling costs due to economies of scale in manufacturing renewable generation. There is no reason why these renewable targets are not achievable if sufficient foresight and planning is given to making this transition from an existing fossil fuel based electricity market.

One of the most significant challenges to adopting high levels of renewable generation is that major sources, like wind and wave power, are described as “variable” or “intermittent”, as their availability is not constant and secure power delivery is not guaranteed. Though much topical research has been conducted, renewable penetration levels over 20% are often not considered and the impacts of market structures in particular are not well known (Kubik et al. 2010).

5.2. Market structure

The electricity markets for the ROI and NI used to be separate, but an all-island single electricity market (SEM) structure for trading wholesale electricity was established on the 1st of November 2007. The SEM operates a capacity payment and gross mandatory pool system that all large (>10MW) generators must bid into. The capacity payments are paid monthly for simply making each MW of capacity available to the network, and for each trading day the market operator (SEMO) selects the most cost effective plant to form an unconstrained schedule to meet forecast demand. The SOs (EirGrid for ROI and SONI for NI) are responsible for applying system constraints and providing generators with a final constrained schedule of how they should operate during each trading period (renewables are given priority dispatch). Plant selected to run is typically paid at a system marginal price for the quantity that it is asked to generate.

This approach is somewhat contrasting to Spain, Germany and Denmark, where forward markets and physical bilateral contracts are used to cost effectively schedule most electricity trades under market based competition. The impact of market structure on the integration of high levels of renewables (and vice versa) is not well researched and is an area of particular research interest to the authors.

Many European countries, including Spain, Germany and Denmark have liberalised their energy markets in response to EU directives, moving from vertically integrated utility monopolies to a market where generation and supply are open to competition. The same is true for Ireland, which in 2000 had 98% of generation in the ROI owned by semi-state owned company ESB. Following the various EU liberalisation directives and the formation of the SEM this had fallen to 30% in 2008 (ESB 2008).

In physical terms Ireland shares some similarities in particular with Denmark. Both possess a similar market size and a strong renewable resource potential, as well as interconnected but separate transmission grids that are part of a common wholesale market (NI & ROI and DK1 & DK2, respectively). Denmark forms an interesting insight into how Ireland may develop, with high levels of distributed power in the form of CHP and wind. However, it is much better interconnected to other countries than Ireland and uses this as a mechanism to deal with the high levels of wind it has on the grid, an approach Ireland cannot emulate.

5.3. Renewable policy

Each country covered in this paper has taken a slightly different approach to policy promoting grid decarbonisation, though all currently offer some form of the feed-in

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tariff. Ireland’s policy drivers are somewhat complicated, as it operates under two different policy incentives in NI and ROI. In NI, a quota based system (the Renewable Obligation, or RO) is used, in line with the UK based policy. In the ROI, a feed-in tariff was introduced in 2006, providing a guaranteed 15 year price covering most renewables. Recently, a set of terms and conditions has been proposed to extend the feed-in to cover offshore wind, marine and other emerging technologies. Curiously in the ROI, the feed-in tariff is not paid to the generators but rather to the suppliers because of the mechanics of the market. This creates competition between suppliers to form Power Production Agreements (PPAs) with generators (IWEA 2010).

Each government’s approach has demonstrated advantages and limitations:

The German feed-in is a low risk approach for investors, as renewable generators are not exposed to power trading and receive guaranteed payments. In Germany, balancing and transmission reinforcement costs are paid by the TSO and passed on via a UoSC. While setting very favourable conditions for development, a criticism of this approach is that it provides no incentive to minimise costs, as they are all passed on.

Spain offers a choice of a fixed feed-in or a feed-in premium; around 97% of wind generators chose the latter in 2007 (Klessmann et al. 2008). Renewable generators are expected to pay some balancing costs if they fall outside an acceptable threshold of accuracy, and are expected to contribute some of the costs of transmission reinforcement. This can be described as a medium risk approach; renewable generators have an incentive to minimise costs and to make larger profits, but still receive a guaranteed minimum. The main criticism of Spain’s policy is ambiguity over renewable generators’ contributions to grid reinforcement costs.

A different support policy is the quota based RO, which requires suppliers to source a certain percentage of their electricity from renewable sources. In the UK (including NI), it is implemented through trading of Renewable Obligation Certificates (ROCs), separate to normal electricity market trading. The reason for this approach is that a free market philosophy is the best mechanism for minimising the costs of meeting the renewable quota for the year. However, it exposes investors to high levels of risk as there is no guaranteed profit on either trading renewable electricity or ROCs.

Various analyses of the above policy mechanisms show agreement that the fixed feed-in has been the most effective in the past (e.g. Swider et al. 2008), with particular praise for the German model. There have been suggestions that the German business ethic places high value on self regulation, and this is a contributing factor to the success of their feed-in tariff in absence of a state-owned SO.

CONCLUSIONS

This paper has reviewed the progress of Spain, Germany and Denmark in developing their renewable capacity and compared this to the situation in Ireland. A number of key comments may be drawn from the findings.

The level of risk to potential renewable investors is important to policy design. Low risk policies (e.g. the German fixed feed-in) provide best incentive to invest, but do not encourage minimisation of cost. Conversely high risk

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policies (quota based schemes like ROCs) encourage minimum cost, but are less attractive to investors.

All electricity markets have some structural variations, and the Irish capacity and pool structure in particular is notably different to the other European designs discussed in this paper. The implications of the SEM structure on integrating high levels of renewables are not well known, and are an area of particular research interest to the authors.

The main weakness of the Spanish approach is uncertainty over connection costs. For Germany it is the ambiguous manner in which renewable electricity is converted into a standard load profile and how this cost is passed on via a UoSC. In Denmark the largest barrier to renewable development was an extended period of policy uncertainty. It is therefore advisable that Irish policy makers consider these weaknesses and avoid making the same mistakes.

High levels of interconnection have been an important factor in Denmark mitigating some of the challenges of developing a wind penetration of 20%. Despite its similarities, Ireland will struggle to emulate this as it is geographically isolated.

Ireland remains a country with a great potential for future renewables development. However, its 2020 target is ambitious; a 30-40% renewables penetration level is greater than has been seen in any liberalised energy market to date. Further research is required to understand the implications that particular market designs will have on the adoption of high levels of renewables and vice versa. However, Ireland has access to better technology, lower turbine costs and a wealth of best practice experience that Spain, Germany and Denmark did not at the outset of their renewable drives. There is no reason to believe these ambitious targets are not achievable over the next decade if sufficient foresight and planning is given to making the transition from an existing fossil fuel based electricity market.

ACKNOWLEDGEMENTS

The authors wish to thank Mads Lyngby Petersen from Energinet.dk for his clarifications on the Danish market and Nord Pool.

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Vertical Axis Wind Turbines (VAWTs) in the Built Environment and

Computational Fluid Dynamics (CFD) Simulations

R. Nobile1*, Dr A.Mewburn-Crook2, P. Humphries2

3Dr M. Vahdati, 4Dr J. Barlow

1 Technologies for Sustainable Built Environments, University of Reading, UK 2 Wind Dam Ltd, Devon, UK

3School of Construction Management and Engineering, University of Reading, UK

4Department of Meteorology, University of Reading, UK

*Corresponding author: [email protected]

ABSTRACT

In the last few years, the use of wind energy in the built environment has

received an increasing interest from public, political and business sectors, as

several studies have shown that Vertical Axis Wind Turbines (VAWTs) are

more suitable for urban areas than Horizontal Axis Wind Turbines (HAWTs).

The advantages of VAWTs over HAWTs are mainly: omni-directional without

a yaw control, aesthetics to integrate to buildings, more efficient in

turbulent environment and low sound emissions than HAWTs.

The aim of the paper is to give an overview about the present work that has

been done in the field of diffuser augmented wind turbine (DAWT), review

the concepts behind VAWTs and present few results obtained from

Computational Fluid Dynamics (CFD) simulations for the airfoil of an

Augmented Vertical Axis Wind Turbine (AVAWT).

Keywords: Vertical axis wind turbine, Horizontal axis wind turbine, Computational fluid dynamics, Built environment, Diffuser augmented wind turbine.



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A review of domestic hot water demand calculation methodologies and their

suitability for estimation of the demand for Zero Carbon houses.

R. Burzynski1*, M. Crane2 and R. Yao3

1 Technologies for Sustainable Built Environments, University of Reading, UK

2 SSE Utility Solutions, Thatcham, UK

3 School of Construction Management and Engineering, University of Reading, UK


ABSTRACT

In 2006 a typical UK household used about 26% of its total energy consumption for

hot water preparation. Zero Carbon houses, which are to become a mandatory

standard from 2016, are characterised by a very high level of thermal insulation,

significantly reducing their space heating requirements and bringing the

proportion of hot water energy to a much higher level. Therefore, for such

buildings the accuracy of hot water demand estimations becomes much more

important than for a typical residential building. This paper presents results of a

review of methodologies used to estimate hot water demand in the UK dwellings.

Special attention is given to the suitability of the methodologies for the demand

estimation in houses built to the Zero Carbon standard. The paper also presents an

outline of the Greenwatt Way Zero Carbon housing development with its energy

performance monitoring programme. The monitoring will help to verify practically

the suitability of the existing hot water demand estimation methodologies for

modern houses.

Keywords:

Domestic Hot Water, Water Efficiency, Sustainable Solutions, Sustainable Homes

1. INTRODUCTION

In October 2008 the UK government announced very ambitious targets to reduce

greenhouse gas emissions by at least 34% by 2020 and 80% by 2050 against a 1990

baseline [1]. This commitment is spread across all industries including the housing

sector. In 2008 final energy consumption in the UK domestic sector increased by 3%

compared to 2007 and by 15% since 1990 [2]. According to DEFRA’s statistics [3]

energy consumption by end user in the residential sector accounted for 28% of

carbon dioxide emissions in 2006. Space heating and hot water alone in residential

buildings accounted for 13% of the UK’s greenhouse gas emissions. The UK Low


13

Carbon Transition Plan [4] envisages that by 2050 these emissions are to be reduced

to almost zero by improving energy efficiency and utilising more low carbon energy

solutions.

According to the DECC’s statistics [5] energy used for hot water preparation

constituted about 30 % of the total domestic heat consumption in 2007. These

statistics have been derived from data collected from all the UK households;

therefore they are not necessarily applicable to modern houses built to the Zero

Carbon standard, which will become a mandatory requirement from 2016. Zero

Carbon houses are characterised by a very high level of thermal insulation with

significantly reduced space heating requirements. Therefore, the proportion of

energy used for hot water preparation out of total dwelling heat demand is

expected to be close to 60%. Resultantly, the accuracy of the hot water demand

estimations becomes more important for the design of an efficient heating system.

There are a few methodologies commonly used for estimation of hot water demand.

Unfortunately, none of them has been practically verified for houses built to Zero

Carbon standard yet.

2. REVIEW OF HOT WATER DEMAND ESTIMATION METHODOLOGIES

Domestic hot water consumption is a key variable for the design and planning of a

heating system. However, it is not possible to precisely calculate the consumption

as in practice it can significantly vary. Two similar families living in identical

neighbouring homes could use significantly different amounts of hot water.

Another important parameter of hot water consumption is the rate at which water

is drawn from the heating system. This is usually presented as a histogram of the

consumption on a typical day (working and weekend day). Figure 3 and Figure 4

present patterns of such demand from monitoring projects first in UK and second

in USA.

Figure 3 Average daily hot water consumption in UK [6].

Figure 4 Average weekday/weekend daily hot water consumption profiles for 15-unit building in USA [7].

13

In both figures it is clearly visible that the hot water demand has two peaks. For UK

first peaks is at about 9 am and the second one lower than the first one at about 6

pm. For the example from USA first peak on a working day occurs around 8 am and

the second one, higher than the first one at around 9 pm.

Some good practice guides provide rough estimations of the amount of hot water

required by a household. For example in BSRIA’s Rules of Thumb handbook [8] it is

recommended to estimate daily consumption based on number of bedrooms.

According to this book for a single bedroom, two bedroom and three or more

bedroom dwellings the amount of hot water should be estimated at 115 litres, 75

litres and 55 litres per bedroom respectively. Alternatively, BS6700 [9] recommends

that hot water (60°C) consumption of a dwelling should be estimated between 35

litres and 45 litres per person per day. Yao and Steemers [10], based on data

provided by Marsh [11], envisage that the energy consumption breakdown of a

typical UK household will comprise of bathing/shower - 16%, washing hand in a

basin - 21%, dish washing - 34% and clothes washing - 29%. In contrast the

breakdown of the energy consumption in typical American family as reported by

Harvey [12] reveals that 51% of total hot water consumption is used for showers, 23

% for baths, 10 % for dishwashers and 16 % by washing machines (excluding system

standing and distribution losses). Harvey also concludes that even if showering and

washing habits of people living in sustainable houses do not change the hot water

consumption for showering and washing can be halved if water efficient fixtures

replace standard ones.

However, the most commonly used methodology for estimating domestic hot water

demand has been defined in BRE Domestic Energy Model (BREDEM) [13].

This methodology was also used to establish the Government’s Standard

Assessment Procedure for Energy Rating of Dwellings (SAP) which is enforced by

Building Regulations to assess energy and carbon (CO2) performance of new and

existing domestic buildings.

In the BREDEM the estimation of hot water demand and related energy demand is

based on the expected number of occupants (N) which is in turn related to the total

floor area (TFA) of a dwelling. However, as the authors of BREDEM indicate that this

relationship is only a rough indicator, as there is a large variability in practice. In

the most recent version of BREDEM 12 (updated in 2001) the standard number of

occupants, N is given by Equation 1.

if TFA ≤ 450 N = 0.0365 TFA - 0.00004145 x TFA2,

if TFA > 450 N = 9/(1+54.3/TFA)

(Equation 1)

Where: N is the assumed number of occupants and TFA is the total floor area of the

dwelling in m2.

Furthermore, the annual, daily hot water usage (Vd,average) is defined by Equation 2.

13

Finally, assuming a 50°C temperature rise (from 10°C of mains water to 60°C within

a cylinder and a 15% loss of energy between the tank and tap), the hot water energy

at the tap Qu is given by Equation 3.

The authors of BREDEM state that the above demand function applies to an average

household, but the following adjustments to Qu can be made to account for

different levels of usage: above average +20%; below average -20%; well below

average -40%.

The aforementioned equations were slightly adjusted when implemented to SAP

2005 methodology. Equation 4 from SAP 2005 revision 3 allows calculating the

number of occupants.

if TFA ≤ 420 N = 0.035 x TFA - 0.000038 x TFA2,

if TFA > 420 N = 8 (Equation 4)

The annual, daily hot water usage (Vd,average) is defined by Equation 5.

Hot water energy (Qu) at the tap is given by Equation 6.

The Energy Saving Trust report [14] on the field monitoring of over a hundred

domestic hot water systems confirmed that the current BREDEM/SAP model of the

consumption (based on the number of occupants in a dwelling) is appropriate.

However, the assumption of a 50°C temperature rise of hot water in the cylinder

was found to be incorrect. The monitoring data shows that the average temperature

rise of water in the cylinder was about 36.7°C, which is significantly lower than the

one assumed in BREEDEM. This was partly due to a higher than assumed cold water

feed temperature (mean value 15.2°C) and a lower than assumed hot water

temperature (mean value 51.9°C).

Vd,average = 25 x N + 38 [litre/day] (Equation 2)

Qu= [(52 x N) +78] x 8.76 [kWh/year] (Equation 3)

Vd,average = (25 x N) + 38 [litre/day] (Equation 5)

Qu = [(61 x N) + 92] x 0.85 x 8.76 [kWh/year] (Equation 6)

13

It is worth mentioning that the 10°C difference in water temperature results in 20%

energy savings in. Hot water consumption of the dwellings monitored in the EST

project would be over-predicted by BREDEM by approximately 35% [14].

Further investigation has also been carried out of the relationship between the

number of occupants and the floor area using data from English House Condition

Survey [15].

All aforementioned findings led to further changes of SAP. The recently introduced

2009 version of SAP has improved algorithms for all three parameters: number of

occupants, daily hot water demand and the hot water energy.

The algorithm for the number of occupants N is currently more sophisticated and is

expressed by Equation 7.

if TFA > 13.9: N = 1 + 1.7 -exp (- -13.9)²

)] +

-13.9)

if TFA ≤ N = 1

(Equation 7)

Where: N is the assumed number of occupants and TFA is the total floor area of the

dwelling in m2.

Annual, average, daily hot water usage Vd,average has also been slightly adjusted by

reducing the fixed consumption by 2 litres. Current algorithm is presented by

Equation 8. Monthly variation of hot water demand may be calculated using factors

from Table 4.

Finally, hot water energy (Qu) at the tap is given by Equation 9.

Where: nm is a number of days in month m4, Vd,m is a daily use of hot water

adjusted by factor from Table 4 and ΔTm is the temperature rise for month m from

Table 5.

4 For February the number of days is fixed to 28.

Vd,average = (25 x N) + 36 [litres/day] (Equation 8)

3600/19.412

1, mm

mmdu TnQ V

[kWh/month] (Equation 9)

13

Table 4 Monthly factors for hot water use

Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Annua

l

1.10 1.0

6

1.02 0.98 0.94 0.90 0.90 0.94 0.98 1.02 1.06 1.10 1.00

Table 5 Temperature rise of hot water drawn off (ΔTm, in C)

Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Annua

l

41.2 41.

4

40.1 37.6 36.4 33.9 30.4 33.4 33.5 36.3 39.4 39.9 37.0

SAP 2009 also introduced a provision for reducing annual hot water usage by 5% in

cases where the dwelling is designed to achieve a water use target of not more that

125 litres per person per day (all water use, hot and cold) [16]. However, this

provision will always have to be used since the new Approved document G [17]

requires all new dwellings to have wholesome water consumption not greater than

125 litres per person par day. In addition to that, some boroughs, especially in

London, require from the developers to build new houses to a minimum of Code

Level 3 of the Code for Sustainable Homes (CSH) with Wales and Northern Ireland

also making this obligatory for all new housing supported by public funding [18].

Such houses should be designed and built in such a way that the water

requirements should not exceed 80 litres per person per day. This is often achieved

by installing grey and rain water recycling systems along with low flow water

fixtures. Some developers have even greater aspirations than Code Level 3 and have

started building houses to the Code Level 5 and Code Level 6 (Zero Carbon).

The impact of all of the aforementioned changes to the BREDEM/SAP

methodologies of the hot water energy demand of dwellings of total floor areas up

to 150 m2 have been presented in Figure 5 and Figure 6. Figure 5 clearly shows that

there is quite significant difference in the results of calculation of occupancy for

dwellings of total floor area more than 100 m2. It is also surprising to see that the

occupancy seems to be limited to about three occupants even for very large

dwellings. The second chart shows that even for small dwellings there is noticeable

reduction in estimations of hot water energy demand calculated using BREDEM

12/SAP 2005 and SAP 2009 methodologies.

However, it is rather difficult to evaluate whether the new algorithms and

additional provision of a 5% reduction of “standard” hot water demand would be

sufficient to reflect a potential reduction of hot water demand in houses build to

high level of the CSH.

13

Figure 5 Changes in estimations of occupancy as function of total floor area for discussed methodologies.

Figure 6 Changes of hot water energy demand estimations as function of total floor area for discussed methodologies.

3. MONITORING OF ENERGY PERFORMANCE OF GREENWATT WAY THE ESPERIMENTAL ZERO CARBON DEVELOPMENT

Expecting significant changes in energy consumption of new houses that can affect

energy supply business in UK, SSE, one of the UK’s major energy utilities, has

developed a Zero Carbon housing project called Greenwatt Way. The main aim of

the project is to study energy usage and individual occupant’s interaction with

energy efficient Zero Carbon homes. As part of this study, the hot water demand

will be monitored and the results will be used to verify practically the suitability of

the existing hot water demand estimation methodologies for modern Zero

Carbon/Sustainable houses.

The development is located in Slough, about 20 miles west of London and is shown

in Figure 7. The site consists of ten dwellings; two 1 bed apartments (45 m2 each), a

terrace of three 2 bed houses (80 m2 each), a terrace of three 3 bed houses and two

3 bed detached houses (94 m2 each). There is also a renewable Energy Centre and an

Information Centre. The project partners combined conservative architectural

design with the latest construction methods, technologies and sustainable features

available in order to deliver Zero Carbon housing to Level 6 of the Code for

Sustainable Homes.

Occupancy per TFA

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

15 30 45 60 75 90 105 120 135 150

Total Floor Are of Dwelling [m2]

Occu

pan

cy

N-BREDEM-12 N 2005 N 2009

Hot Water Energy Demand

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

15 30 45 60 75 90 105 120 135 150

Total Floor Are of Dwelling [m2]

En

erg

y [

MW

h/y

ear]

QBREDEM-12 QBREDEM-12 -40%

Q2005 Q-2009-5%

±20%

13

Figure 7 Aerial view of Zero Carbon Housing project in Slough.

Figure 8 Integrated renewable energy centre with district heating scheme.

The homes are equipped with modern hydraulic interface units (HIU) which provide

energy for space heating and hot water. The schematic of the HIU and its key

components is presented in Figure 9. Low carbon heat is supplied to each HIU from

the site’s renewable Energy Centre (Figure 8) via a low temperature district heating

(DH) scheme. The district heating scheme is built with a pre-insulated twin pipe

system which aims to reduce heat loses.

The district heating scheme operates at a flow temperature of 55°C and the domestic

hot water is supplied at 43°C via an on-demand heat exchanger in each house. The

radiators and hot water heat exchanger in all homes are directly connected to the DH.

The heat loads in the house are designed to achieve the lowest possible DH return

temperature to minimise heat losses and maximise the heat pumps coefficient of

performance.

40 kW

10 kW District Heating

Space Heating

Hot Water

10°C

43°C

55°C

35°C

55°C

20°C

Figure 9 Key parameters and schematic of Hydraulic Interface Unit (HIU).

13

The research programme includes several work streams with an initial monitoring

programme of two years and includes:

Modelling and monitoring of the energy performance of the renewable energy centre, district heating scheme and domestic heat and power demand.

A post occupancy evaluation of the tenants.

An evaluation of the whole house mechanical ventilation with heat recovery system (MVHR).

A demonstration of hot fill washing appliances and energy efficient smart kit.

An electric vehicle car share scheme for residents.

Monitoring of water usage.

4. CONCLUSIONS

The review of methodologies used to estimate hot water energy demand of the UK

dwellings shows that there is a limited number of methods used for this purpose.

The most advanced one was derived from BREDEM model. The methodology has

been recently verified and updated using data from the hot water monitoring

project from more than 100 UK dwellings. Generally the update resulted in

significant decrease of hot water demand estimations per square meter of dwelling.

However, the data collected during the monitoring project did not cover CSH Level

3 and higher Code Levels houses. Therefore, it is still some uncertainty whether

currently used models are accurate enough to model hot water demand in Zero

Carbon houses. The monitoring programme of the Greenwatt Way project should

help to verify and improve the suitability of the methodologies for modern Zero

Carbon/Sustainable houses.

13

5. REFERENCES

[1] DECC, Climate Change Act 2008, DECC, Ed., ed. London, 2008.

[2] DECC, UK Energy in Brief 2009, DECC, Ed., ed. London: National Statistics,

2009.

[3] DEFRA, The environment in your pocket 2008, DEFRA, Ed., ed. London:

National Statistics, 2008.

[4] H. Government, The UK Low Carbon Transition Plan, ed. London: The

Stationery Office, 2009.

[5] DECC, Energy Consumption in the UK. Domestic Data Tables, 2009 Update ed:

A National Statistics Publication, 2009.

[6] Energy Monitoring Company, Measurement of Domestic Hot Water

Consumption in Dwellings, DEFRA 2008.

[7] E. Vine, et al., Domestic hot water consumption in four low-income apartment

buildings, Energy, vol. 12, pp. 459-467, 1987.

[8] K. Pennycook, Rules of Thumb, 4th Edition ed.: BSRIA, 2003.

[9] British Standard, Design, installation, testing and maintenance of services

supplying water for domestic use within buildings and their curtilages

Specification, in BS 6700:2006+A1:2009, ed: BSI, 2009.

[10] R. Yao and K. Steemers, A method of formulating energy load profile for

domestic buildings in the UK, Energy and Buildings, vol. 37, pp. 663-671, 2005.

[11] R. Marsh, Sustainable housing design: an integrated approach, Ph.D thesis,

University of Cambridge, 1996.

[12] L. Harvey, A handbook on low-energy buildings and district-energy systems:

fundamentals, techniques and examples: Earthscan, 2006.

[13] B.R. Anderson, et al., BREDEM-12 Model description, 2001 update: IHS, BRE

Press, 2002.

[14] EST, Measurement of Domestic Hot Water Consumption in Dwellings, DEFRA

2008.

[15] BRE, A review of the relationship between floor area and occupancy in SAP,

Building Research Establishment 2009.

[16] DECC, The Government’s Standard Assessment Procedure for Energy Rating of

Dwellings, DECC, Ed., Version 9.90 ed. Garston: BRE, 2010.

13

[17] Secretary of State, Building Regulations, Approved Document Part G -

Sanitation, hot water safety and water efficiency, UK Government, Ed., ed:

NBS, 2010.

[18] DCLG, Code for Sustainable Homes - Technical Guide, DCLG, Ed., May 2009 ed,

2009.

13



Sustainable Data Centres – Approaches and Challenges

S. Luong1*, K. Liu1, S. Chong2

1Technologies for Sustainable Built Environments, University of Reading, UK 2Capgemini UK, Sale, UK


ABSTRACT

Data centres are increasingly becoming an essential component for many

organisations. With the emergence of highly sophisticated and integrated IT

services the market is demanding for more computing and storage power. This

means that data centres are expanding at a remarkable rate in response to demand.

While this may bring more business for an organisation they have started to realise

their environmental objectives and the statistics of a data centres’ energy

consumption. Having reviewed the current issues of sustainable data centres, this is

an introductory paper that proposes a research objective on the sustainable

applications of data centres. The proposed solution highlights the use of agent

technology for cooling systems in a data centre environment and whether a pre-

emptive cooling system is more energy efficient than a reactive cooling system.

Keywords:

Data Centres, Sustainability, Green Technology

1. INTRODUCTION

This paper introduces what a data centre is, and the application of sustainability to

an intensive energy-consuming company asset. The aim is to provide an abstract

overview of a new research project that is in progress at the TSBE Centre,

University of Reading in collaboration with Capgemini UK. The motivation behind

this project is to highlight and tackle the issue of energy consumption and carbon

emission footprint in data centres. If no action is taken now data centres could

potentially be aligned next to transportation and buildings as one of the most

environmentally harmful human systems.



13

Organisations around the world are under increasing pressure to conduct business

in a more environmentally friendly way. Many of them rely on data centres to run

their business activities and IT services. To emphasise the severity, the UK has

committed themselves to “reduce carbon emissions by large ‘low energy-intensive’

organisations by approximately 1.2 million tonnes per year by 2020, and to reach

an 80% reduction by 2050” (DECC, 2010). A mandatory carbon trading scheme that

started in in April 2010, governed by CRC Energy Efficiency Scheme (2009), will

have an impact on larger businesses. This impending consequence raises a research

question: is it possible to reduce energy consumption and carbon emissions from

data centres and maintain support for growth and continuity for a sustainable

business. The research project revolves around the philosophy of sustainability and

how it is applied to data centres.

The paper is presented as follows. In section 2, we describe what a data centre is, its

history and infrastructure. Section 3 discusses the topic of ‘green’ and

‘sustainability’ in the context of data centres. An assessment of the current state-of-

the-art energy-aware technologies in data centres is presented in section 4. Finally,

we conclude and lay the basis of our future work plan in section 5.

2. DATA CENTRES

A data centre is defined as “a facility used for housing a large amount of computer

and communications equipment maintained by an organisation for the purpose of

handling the data necessary for its operations” (MSDN, 2010). While this definition

abstract it is actually referred to as typically, the facility and floor space is occupied

mainly by IT equipment. In the IT industry, a data centre houses the state-of-the-art

service provider technologies hosted by computer servers, storage devices and

networking equipment. They are some of the most expensive hardware that any

organisation would purchase to support the business operations and activities. They

are identified as major asset to the organisation due to its role in the organisation

and the invaluable data it stores.

2.1 Data Centre History The history of data centres started when the microcomputer industry was

introduced in the 1980s. The IT equipment were large, room sized machines that

needed cables to connect all the components together and a special environment to

operate in. Maintaining and operating these machines was a highly complex task

because each component performed a particular function and cable management

was vital to ensure that the administrators were able to identify each component

and how they communicate. This led to the practice of isolating them into

dedicated rooms. Initially, the military were using these machines. They were very

expensive and the need for heavy security was deployed to control access to the

machine. Eventually, other organisations and businesses invested in these

computers for their own ventures. Due to the equipment consuming huge amounts

of power they would generate lots of heat. Cooling systems were essential to allow

the machines to function without overheating – another reason to keep the

13

expensive equipment in a dedicated, climate controlled environment. Eventually,

computers were being installed everywhere as a way of helping organisations to

perform their operations and establishing internet presence. The birth of data

centres was marked in the 1990s when companies tried to reduce the complexity of

the IT equipment by organising them in a controlled environment. This led to the

introduction of the client-server architecture and so the computer servers found

themselves a home in a closet or dedicated rooms.

2.2 Controlled Environment

The IT equipment in a data centre benefits from a luxurious environment with

many other expensive hardware to ensure that it lives in a controlled and optimal

environment. The four primary components of a data centre consist of the

following:

1. Electrical power – includes the primary and standby power generators that are located on site, the distribution units for directing power to the required locations and conversion adaptors from converting AC power from the grid to DC power.

2. Cooling – includes chillers for dissipating heat from water via heat exchangers, heaters and air conditioning to ensure the environment is at the correct temperature and ventilation for the intake of external air and exhaust for hot air.

3. Floor space and cable management – includes the management of maximising floor space, using raised floor to improve cooling capabilities and under floor or overhead cable conveyance.

4. Practices and management – includes being compliant with local legislations, internal policies and regulations, International Standards Organisation (ISO) guidelines and environmental health and safety.

The above are the essential components for a data centre environment (Schulz,

2009). There are many other components that make up a data centre but not all are

essential as they vary in size, shape, what it was designed for and technology

preference.

2.3 Data Centre Classification

As of current, the Uptime Institute of America (2010) has defined (and updated) four

tiers of data centres, which was reviewed by the Telecommunications Industry

Association (2006). Organisation’s design and construct their data centres to these

requirements and aim to be certified by the Uptime Institute of America to reduce

risk and cost, and achieve long-term business value. Tier 1 represents the lowest

availability and level of protection, and tier 4 being the highest cost to implement

and most expensive environment. The four tiers are:

13

Table 2: Four tier data centre classification

Tier 1 Tier 2 Tier 3 Tier 4

- 99.671%

Availability

- Single

distribution path

- No redundancy

(N)

- Tier 1

requirements

- 99.741%

Availability

- Single

distribution path

- N+1

- Tier 2

requirements

- 99.982%

Availability

- Multiple

distribution paths

- Concurrently

maintainable

- Tier 3

requirements

- 99.995%

Availability

- Multiple

independent

distribution paths

- Fault tolerance

for all components

The requirements outline the level of infrastructure to sustain normal operations. It

takes into consideration the annual down time, the number of paths for power and

cooling distribution, whether it includes redundant components, maintenance and

fault tolerance. For example, a tier 2 data centre includes the requirements of tier 1,

allows an annual down time of 22 hours, single path for power and cooling, and the

main set of components has been mirrored (N+1) so there are two identical set of

components. A tier 4 data centre includes the requirements of the previous three

tiers but this type of data centre can sustain a worst case disruption scenario with

multiple paths for power and cooling but from different independent sources,

multiple redundant components and an annual downtime of 24 minutes.

2.4 Cooling & HVAC (Heating, Ventilation & Air Conditioning) Cooling and HVAC must be incorporated into the design stage of a data centre as

there are many ways of providing cool air to the IT equipment. Power and network

cables can be located on the floor and air conditioning provided through the ducts

in the ceiling. The physical layout of the data centre varies as there is no single

configuration. However, for more efficient cooling a raised floor solution offers

practical benefits in comparison to a non-raised floor as discussed by Schulz (2009),

Snevely (2002), Uptime Institute (2010) and TIA-942 (2006) Data Centre Standards.

Additionally, the server cabinets should be arranged to form a “hot” and “cold”

aisle.

The cabinets are placed face to face on a raised floor. The front of the cabinets is

facing each other in an alternating pattern. The power and network cable

conveyance are placed underneath the raised floor. The front of the cabinet draws

cold air from the floor through perforated tiles and expels hot air out the back. The

hot aisle has no perforated tiles to prevent the hot and cold air from mixing. A

typical room layout portrayed in figure 2.1 shows how conditioned air is forced into

the supply plenum and kept pressurised so that the air can escape through the

perforated tiles. The servers in the cabinets draw the cold air from the supply

13

plenum. Hot air is expelled out of the cabinets and rises up to the return plenum.

The CRAC units restart the whole cooling process by drawing hot air from the

return plenum.

Figure 2.1 Cold air / hot air plenum

In figure 2.2 both ends of the room have computer room air conditioning (CRAC)

units. The cabinets are aligned in rows so that the hot aisle and cold aisle are

separated. In order to maximise the cooling efficiency this type of configuration

uses raised floors and ceiling tiles to create plenums: cold air (supply) plenum and

hot air (return) plenum.

Figure 2.2 Hot Aisle Cold Aisle Configuration

The cooling configurations described here are reaching its limitations as component

footprint per square feet of floor space is increasing; therefore using more power

and generating more heat. The cooling units are reaching maximum capacity and

this could be a serious problem for the future of data centres.

3. DATA CENTRE SUSTAINABILITY

The two most widely used definitions of sustainability are:

13

1. “… conserving an ecological balance by avoiding depletion of natural resources” (Oxford, 2010)

2. “… meeting the needs of the present without compromising the ability of future generations to meet their own needs” (UN Documents, 1987) .

They both imply the principle of not causing irreversible environmental damage.

The term sustainability is widely applied to human sustainability on planet Earth.

There are many theorised problems that humans are going to encounter in the

foreseeable future. On the current development model the Department of

Economic and Social Affairs (2008) estimated that the population will increase to

over 9 billion by 2050. There will not be enough resources for distribution to

everyone as the Earth has a fixed amount of natural resources. Electricity is

generated by burning fossil fuels: its major by-product is carbon dioxide and it is a

limited resource. However, carbon dioxide is one of the greenhouse gases that are

produced by human activities. There are strong evidence linking greenhouse gases

to anthropogenic causes and if no action is taken now it would cause irreversible

damage to the environment.

Statistics show that data centres are heavy consumers of electricity. In the United

States, data centres consumed $4.5 billion of electricity alone with a predicted

growth rate at 12% per year (Scheihing, 2009). In Western Europe, the European

Commission (2008) estimated that data centres consumed 56 TWh per year in 2007.

Based on the Department of Energy and Climate Change’s (DECC, 2008) price

assumption this estimates to £3.14 billion. If data centres continue to grow at its

current pace it will put immense strain on power stations to produce more

electricity, which means more fossil fuel has to be burnt and therefore seriously

increasing the carbon footprint of the data centre.

3.1 Difference between Green & Sustainability

Over the years, the word ‘green’ and ‘sustainable’ has been used interchangeably,

which has caused much confusion as to be green is not the equivalent of to be

sustainable. The word ‘sustainable’ has been diluted for commercialisation, which

does not help those trying to understand the philosophy of sustainability. To be

green is to change your life style to be more environmentally friendly, use energy

efficient products, reusing and recycling waste and water, etc. But to be sustainable

is actually going beyond just ‘being green’. Sustainability is a continuous process

lasting indefinitely or to simply put it ‘to be zero energy’. Being sustainable is to use

sustainably harvested or renewable sourced products without causing irreversible

damage to the ecosystem. Realistically, applying the definition of sustainability to

data centres could be an impossible task given the circumstances of our economy

and how the world relies on energy to exist. In this context, we could only follow

the guidelines of making data centres use energy responsibly and restore, as much

as possible, whatever has been consumed.

13

3.2 The Sustainable Data Centre

A green data centre is designed for maximum energy efficiency and minimum

environmental impact. Although this is achievable through advancing technology

and strategy this will not solve the long term issue. We will attempt to differentiate

a green data centre from a sustainable data centre.

“A sustainable data centre should provide normal business operations with as close

to having a zero environmental impact as possible under current technology

constraints whilst maintaining economic growth.”

Our definition here suggest that rather than just focusing on greening the data

centre we should ensure the data centre fits to the organisations mission statement

of meeting their environmental targets. However, it should extend further to

meeting local or even enterprise targets of minimising their long term impact to

the environment by working within the technology barriers and offer flexibility for

the business to respond to future demands. It could be the case that a data centre

uses a wind farm, PV panels and fuel cell technology to supply power as the

technology is already available. It also means to play its role as not a single entity

but part as a global wide initiative of helping the organisation, government and the

country to meet its environmental objectives. It is inevitable for a data centre to

expand and continue to grow. But, if advancement in technology presents an

opportunity for the greater good and operating sustainably then that organisation

should take responsibility and use new technology where possible to help sustain

the long-term strategy of preserving the environment for future generations.

3.3 Standards and Guidelines

There are a number of standards and guidelines to which a well-built data centre

should conform. Besides the Data Center Site Infrastructure Tier Standard by the

Uptime Institute of America there are four other standards and guidelines a data

centre design should adhere to in order to maximise energy efficiency, minimise

environmental impact and improve environmental health and safety. The ISO

14001 standard set the requirements for an environmental management system

(EMS) and guidelines for keeping a log of the environmental performance by

managing the environmental impact, continuously improve performance, and

action objectives and targets in a systematic approach. ASHRAE Environmental

Guidelines for Datacom Equipment set recommendations for data centre

temperature operating range and conditions. The guidelines offer greater flexibility

for data centre operators to set their temperature and humidity controls slightly

higher than they normally would in order to reduce energy consumption. The Code

of Conduct on Data Centres Energy Efficiency is a voluntary initiative designed by

the European Commission that provides a set of aims and targets, which helps

minimise energy consumption and best practice for managing data centre activities.

OHSAS 18001 outlines the assessment specification for Occupational Health and

Safety Management Systems to ensure organisations understand their obligations to

improve the management of health and safety.

13

Organisations are only starting to realise the impact their business operations have

on the environment. They have begun adopting standards and guidelines in

response to recent legislations and policies that have been established. However, it

is not certain that these standards and guidelines could be an inconvenient

checklist that an organisation feels they are obliged to comply with to avoid

penalties. It is certain that when technology advances further and more energy are

required then these standards and guidelines will need to be revised once again to

meet demands of the future.

4. CURRENT APPROACH TO SUSTAINABLE DATA CENTRES

As data centres are a very complex system involving many components there are

various areas that could benefit from research into reducing energy consumption.

Some of the methodologies and practices that industry is currently using are

consolidation, virtualisation technology, thermal management and modular design

and implementation.

Recent research by Srikantaiah et al. (2008) looks at energy optimisation through

consolidation in a cloud computing environment. The problem discussed here is the

“idle power wasted when servers run at low utilisation”. The solution designed is a

consolidation algorithm that utilises the low energy servers but within performance

constraints therefore reducing energy costs without affecting performance. Other

research into consolidation for energy reduction has been carried out by Nathuji

and Schwan (2007), Torres et al. (2008) and Song et al. (2009). Whilst consolidation

may help reduce energy cost, total cost of ownership and underutilised servers it

does not solve the long term fact that more servers has to be installed to support

future demand. Also, delivering a consolidated strategy is complex as there is a risk

of devising the wrong methodology which could result in over-utilising each

physical server.

Generally, energy saving techniques at hardware level is more popular in industry

as hardware is simply “plug and play” and receives immediate results. IBM, one of

the leading server vendors, revived a 40 year old technology to use water cooling at

chip level and supply the wasted heat to nearby offices therefore reducing energy

consumption and carbon dioxide emissions (IBM, 2009). Another research paper

written by IBM researchers discusses the use of dynamic voltage scaling (DVS) that

varies the processor frequency and voltage for energy saving purpose without

affecting system responsiveness and performance (Elnozahy et al., 2003). Lee and

Zomaya (2009) evaluated the use of DVS based on energy-aware task scheduling

algorithm which is fairly similar to the former research. This is a very valuable

piece of research as more processors are being compacted onto a rack. But this

could also have a negative approach: if all processors on a rack are at 100%

utilisation, as it will generate heat very quickly and therefore much more cooling is

needed.

Cooling and HVAC has been continuously refined and upgraded in order to provide

more cooling capacity, energy efficiency and cost reduction. Recent research work

evaluated the use of computational fluid dynamics (CFD) to “determine and

13

optimise the thermal and airflow pattern of the data centre” (Romadhon et al.,

2009). By analysing where most of the heat is generated and the effectiveness of the

cooling system they are able to optimise and configure the rack arrangement to

distribute heat evenly and improve the cooling and air flow. Other in-depth

discussions include an analysis of thermal plumes in the upper regions of a data

centre (Cho and Awbi, 2009). There is a lot of research in this area by both academic

and industry as most of the energy is consumed by the cooling and HVAC systems

rather than the IT equipment. The main objective is to ensure IT equipment

consumption is as close to or equivalent to the power input to a data centre.

5. CONCLUSION & FUTURE WORK

Global warming and climate change are the two major topics that are currently

being discussed everywhere. With the problems being associated to human

activities the UK government will eventually start introducing schemes and

legislations in favour of reducing environmental impact. Organisations are starting

to take action for their responsibilities by conducting business with sustainability in

mind. They are setting themselves carbon emission and energy reduction targets

which in the end will help them save money and be environmentally friendly. We

have introduce what a data centre is, followed by the definition of sustainability

and how it is applied to the concept of sustainable data centres. The state-of-the-art

technology present that a lot of research is in progress into many different

components of a data centre. In future work, we will focus on one particular

component of the data centre – cooling and HVAC systems. The research will

consist of collecting raw data from industry, extensive literature review of

sustainability, data centres, intelligent agents and air conditioning systems and the

design of intelligent zoned air conditioning system for data centres.

REFERENCES

ASHRAE, 2008, Environmental Guidelines for Datacom Equipment – Expanding the

Recommended Environmental Envelope, The American Society of Heating, Refrigerating

and Air-Conditioning Engineers, USA.

Cho, Y. J., Awbi, H. B., 2009, Analysis of thermal plumes in a data centre hall, 11th

International Conference on Air Distribution in Rooms, 2009, Busan, Korea.

CRC, 2009, Carbon Reduction Commitment Energy Efficiency Scheme, Carbon Reduction

Commitment , [online] Available at: http://www.carbonreductioncommitment.info/

[Accessed 05 June 2010].

DECC 2008, Department of Energy & Climate Change, Digest of United Kingdom

Energy Statistics, 2008 Edition.

DECC, 2010, CRC Energy Efficiency Scheme, Department of Energy & Climate Change,

[online] Available at: http://www.decc.gov.uk/ [Accessed 05 June 2010].

DESA, 2008, Population Newsletter, Department of Economic and Social Affairs

Population Division, New York, USA, Number 87.

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Elnozahy, M., et al., 2003, Energy Conservation Policies for Web Servers, 4th Conference

on USENIX Symposium on Internet Technologies and Systems – Volume 4, Seattle,

WA.

European Commission, 2008, Code of Conduct on Data Centres Energy Efficiency Version

1.0.

IBM, 2009, IBM and ETH Zurich Unveil plan to build new kind of water-cooled supercomputer,

IBM Press Room, [Online] Available at: http://www.ibm.com/ [accessed 05 June 2010].

ISO, 2008, ISO 14000 Essentials, International Organization for Standardization,

International Standards for Business, Government and Society, [online] Available at:

http://www.iso.org/ [Accessed 05 June 2010].

Lee, Y. C., Zomaya, A. Y., 2009, Minimizing Energy Consumption for Precedence-constrained

Applications Using Dynamic Voltage Scaling, 9th IEEE/ACM International Symposium on

Cluster Computer and the Grid, 2009, ISBN 978-1-4244-3935-5.

MSDN, 2010, Glossary of MMC Terminology, Microsoft Developer Network, [online]

Available at: http://msdn.microsoft.com/ [Accessed 05 June 2010].

OHSAS, 2007, OHSAS 18001 Health and Safety, Occupational Health & Safety

Standards, [online] Available at: http://www.osha-bs8800-ohsas-18001-health-and-

safety.com/ [Accessed 05 June 2010].

Oxford, 2010, Oxford Dictionaries, [online] Available at:

http://www.oxforddictionaries.com/ [Accessed 05 June 2010].

Nathuji, R. Schwan, K., 2007, VirtualPower: Coordinated Power Management in Virtualized

Enterprise Systems, SOSP’07, Washington, USA.

Uptime Institute, 2010, Uptime Institute LLC, Data Center Site Infrastructure Tier

Standard: Topology.

Romadhon, R., et al., 2009, Optimization of Cooling Systems in Data Centre by

Computational Fluid Dynamics Model and Simulation, Innovative Technologies in

Intelligent Systems and Industrial Applications, 2009, ISBN 978-1-4244-2886-1.

Scheihing, P., 2009, U.S. Department of Energy, Energy Efficiency and Renewable

Energy, DOE Data Center Energy Efficiency Program.

Schulz, G., 2009, The Green and Virtual Data Center, CRC Press, Minnesota, USA, ISBN

978-1-4200-8666-9.

Song, Y., et al., 2009, Utility Analysis for Internet-Oriented Server Consolidation in VM-Based

Data Centers, Cluster Computing and Workshops, 2009, IEEE International

Conference, ISBN 978-1-4244-5011-4

Srikantaiah, S., et al., 2008, Energy Aware Consolidation for Cloud Computing,

Microsoft Research, USENIX, USA.

13

TIA-942, 2006, ADC Telecommunications Inc, Data Center Standards Overview.

Torres, J. et al., 2008, Reducing Wasted Resources to Help Achieve Green Data Centers, IEEE

International Symposium on Parallel and Distributed Processing, 2008., ISBN 978-1-

4244-1693-6.

UN Documents, 1987, Our Common Future, Chapter 2, Towards Sustainable Development,

[online] Available at: http://www.un-documents.net/ [Accessed 05 June 2010].

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Aspects of a Sustainable Community Development Framework

T. McGinley1*, K. Nakata2, S. Chong3

1Technologies for Sustainable Built Environments, University of Reading. UK, 2Informatics Research Centre, University of Reading, UK

3Capgemini UK, Sale, UK

* Corresponding author: [email protected],

ABSTRACT

This paper introduces a research on a user centric and participatory approach to sustainable community development (SCD). The research is structured into three aspects i) requirements engineering, ii) crowd sourcing and iii) human computer interaction. These three aspects act as containers for industrial case studies from Capgemini, the industrial sponsoring company of this research. The three aspects will inform the development of a suite of tool-kits that will provide the core functions of a new SCD framework. An important feature of the research will therefore be the ability to derive generic sustainable development tools from consultant enterprise architecture case studies. In this paper, an approach to developing generic tools that are specific to an aspect of the research will be tested by proposing the first of these three transformations; applying the methodology from a decision support system (DSS) case study for a desktop computing transformation assessment to a user centric DSS for a micro renewable energy supply tool. This new requirements engineering tool will form the SCD framework, it is intended to help users decide which micro renewable technology best fits their requirements.

KEYWORDS:

Requirements engineering; User modelling; Decision support systems; Micro renewable energy; Sustainable community development

1. INTRODUCTION

Sustainable development can be applied to developments that satisfy the three pillars of sustainability; economics, environment and sociology (WHO, 2005). This research seeks to leverage the practice of enterprise architecture through industrial case studies at Capgemini UK and apply these systematic approaches to the challenges that sustainability poses to the built environment. The research poses three main challenges i) how to extract, process and respond to the requirements of the community ii) how to work with large communities and resource the required analysis and iii) how to develop an interface for such a system. These challenges will be approached through relevant industrial case studies that can be plugged into the following three research aspects i) requirements engineering, ii) crowd sourcing, iii) human computer interaction (HCI). The three, aspect specific,



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industrial case studies (Figure 1) combined with aspect specific domain research will be analysed to inform proposals for three generic tool-kits. These tool-kits will form the generic components of a sustainable community development (SCD) framework. The purpose of this paper is to test the framework for the EngD research. To this end this paper describes the translation process for aspect 1 of the research. Figure 1 below describes the structure of the EngD research.

Figure 1. A framework for Sustainable Community Development (SCD)

In this example from Aspect 1 (Figure 1), the Intelligent Workplace industrial case study is a decision support system tool that maps the computing requirements of users in an enterprise to a set of user models. An algorithm has been developed to then map each user models to the optimal model from a set of desktop computing models for that user model. One of the motivations for this tool is to reduce energy use in the workplace by reducing the energy demand of the enterprises desktop computing solution. This method is analysed in terms of requirements engineering including elicitation, evaluation, specification, analysis and evolution. This analysis results in recommendations for a tool kit would map user models to the optimum micro renewable energy model. The remainder of the paper is organised as follows. First we analyse the desktop compute model industrial case study, Intelligent Workplace (Section 3). The method of this analysis is then used in Section 4 to propose a toolkit for a micro generation support system. This approach is then discussed in Section 5.

2. BACKGROUND

The aspect 1 case study will be analysed in terms of Requirements Engineering (RE). Poor requirements have consistently been identified as 'a major cause' of software problems (Van Lamsweerde, 2009). RE has not always been common practice, in 1976 Bell and Thayer produced a paper that argued for the use of RE in software systems. However, today RE can be understood as a process for analysing what the problem is, why it is a problem and who the stakeholders are. It is therefore an essential method for the user model challenges as all these questions need to answered, RE provides us with an understanding of the system 'as is' and the system 'to be'. The method of Requirements Engineering is commonly defined in the following series of steps (Van Lamsweerde, 2009):

Elicitation -> Evaluation -> Specification -> Analysis -> Evolution

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Elicitation indentifies the stakeholders and their requirements. The next stage is to

evaluate and prioritise the identified requirements. These evaluated requirements

can then be represented in a requirements document at the specification stage. The

analysis stage which checks the quality of the requirements is followed by the

evolution stage which tracks the new requirements of the system. The work

described in this paper focuses on the elicitation and specification components of

RE.

The aspect 1 case study from Capgemini responds to the challenge that buildings account for 40% of global energy use (WBCSD, 2009). In the years between 1970 and 1990 direct emissions from buildings grew by 26 percent (IPCC, 2007). However high electricity use in the building sector make this figure closer to 75% than is stated in the direct emissions figure (IPCC 2007). ICT is responsible for a proportion of the emissions from buildings. Therefore Capgemini, a technology consultancy with a commitment to cutting the emissions of its computing solutions is keen to reduce emissions whilst reducing the cost of the electricity bills to the client organisation.

There are many different methods for reducing carbon emissions, the compute

model industrial case study reduces carbon emissions by increasing the efficiency of

the ICT devices that use energy in the enterprise. In 1990 Yoichi Kaya developed the

Kaya Identity to enable countries to calculate their CO2 emissions and understand

what policies may have greatest effect (Rogner et al. 2007). The Kaya Identity

describes four factors that when multiplied together produce an index of emissions,

therefore a reduction in any of the four factors listed below reduces the global

emissions of system.

Energy intensity

Carbon intensity

Gross domestic product per capita

Population

The previous case study examines the reduction of the energy intensity, the applied toolkit will investigate how to reduce the carbon intensity of the energy supply by encouraging energy consumers to obtain their energy from renewable sources. This brings about the first challenge, renewable energy systems can include systems from 1 kW photovoltaic (PV) installations to 1000 MW offshore wind farms (Peças Lopes, 2007). There are a wide range of options available to the consumer and the choice can be confusing. An approach is therefore sought that will rationalise this process, making it easier for consumers to make decisions about their future energy supply. Several papers, notably Arlanne (2007), have investigated using a multi criteria decision support system for micro renewable energy systems. Arlanne's paper focussed on the feasibility of a micro CHP heating system. In contrast, this paper proposes a decision support system to assist communities in their decisions between an extendable selection of micro renewable energy solutions.

3. PRELIMINARY STUDY - DESKTOP COMPUTE MODEL ASSESSMENT

The desktop compute model assessment case study will be analysed in terms of RE and energy intensity. The desktop compute model assessment tool was developed

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by Capgemini to support clients in their transformation towards centralised computing models. This move is a reversal of the shift from mainframe computing to PCs from the 1980s that has stayed with us into the first years of the twenty first century (Want et al. 2002). The motivations for this shift towards centralised computing include an increased demand for energy efficiency throught the intelligent utilisation of shared resources, infrastructure and physical technology that provide increased performance on earlier generations of centralised compute models. However there are multiple models to choose from (we have identified 6 in this study); these models all have different capabilities and the users in an enterprise have different computing and end user experience requirements. It was therefore necessary to develop a tool to standardise the response to this challenging transformation. The following sections describe the development of the tool from a requirements engineering perspective.

3.1 Elicitation

The desktop compute model assessment case study utilised user models and compute models to represent the system capabilities and requirements. The first stage of requirements engineering is to identify the stakeholders in the organisation. The tool was designed to be generic in order to adapt to the different stakeholder constituencies present in different organisations. The user models are described by characteristics that can be gathered by a questionnaire. The characteristics cover four distinct dimensions. the respondent's answers can be weighted, to provide values for each of the dimensions. The dimensions are defined by a white paper from the information technology research firm Gartner (Gammage and Basso, 2009), which identifies four primary parameters to group the user characteristics: mobility, autonomy, business process and collaboration. The definitions of the dimensions are defined in table 1 below.

Dimension Description

Mobility The number of sites that a user operates from as well as the

mobile computing requirement of the user

Autonomy The level of IT management and security required by the user as

well as the level of trust

Business Process

The computational characteristics and execution footprint of

the user’s job function. It can be thought of as an axis of

complexity

Collaboration This axis identifies the collaborative requirement of the user

from real time, complex and rich to voice only.

Table 1. Description of the dimensions

As the result of a series of focus groups we arrived at four user profiles. These are primarily defined into knowledge and information workers. Information workers typically process information whereas knowledge workers transform the information into knowledge by processing the information. These types were then

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divided into offline and mobile workers in order to help elicit their compute models requirements. Resulting in:

Mobile Knowledge worker

Information Worker

Knowledge Worker

Offline Information Worker

The next stage in the process was to map the user characteristics onto the user models using the Gartner dimensions the result of this process is described in table 2 and visualised in figure 2.

User Model (Work Style) Mobility Autonomy Business Process Collaboration

Information Worker 2 1 2 3

Offline Information Worker 1 1 1 2

Mobile Knowledge Worker 6 4 4 6

Knowledge Worker 2 5 6 5

Table 2. User model dimension mapping

Figure 2. User model radar graphs

3.2 Evaluation

This stage of RE focuses on reducing the risk and possibility for conflict associated with the requirements. The evaluation stage is also involved in prioritising the 'best'

User Profile Comparison

Mob

Aut

Bus

Col

InformationWorker

OfflineInformationWorkerMobile KnowledgeWorker

KnowledgeWorker

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options in terms of budget, costs and resources etc. (Van Lamsweerde, 2009). A questionnaire was constructed following a series of focus groups with randomly assigned representatives of the core functions of the organisation. The questionnaire resolved conflicting viewpoints and alternatives into quantitative events by condensing four to six weighted closed questions into one value per dimension. This results in four quantitative values for each user group. This stage does not specifically deal with the risk factors of the requirements. It will be necessary to utilise computational tools to elicit quantitative information about the computational load and end user experience for the applications and operation on the desktop. However, the deployment of these tools will be considered against the cost and inconvenience to the organisation.

3.3 Specification

The user models can be treated as the requirements document of the system. The questionnaire elicits 20 characteristics from the users. The case study will survey 5% of users, in order to achieve 95% accuracy with a confidence interval of 6, in an organisation of 5000 users this makes for 250 * 20 characteristics. This represents a large number of characteristics to understand, therefore we propose to condense the characteristics down to 4 dimensions and fit the 250 users into 4 profiles. It is intended that the condensed data in combination with the simple graphical representation of the users models will make the information easier to read and therefore easier to interpret and analyse. There is a risk however that condensing the information too much or not providing enough variety in the user models could effect the reliability of the results. In a similar respect to the automated computational tools questionnaires are expensive and should be used strategically.

3.4 Analysis

The user models will then be applied to a set of 6 compute models below,

Physical Desktops and Laptops Hosted shared Desktops

Client Desktop virtualisation Hosted VDI Desktops

Local streamed Desktops Hosted Blade PC's Desktops

Physical Desktops and Laptops describes the traditional approach to desktop compute models, however recent developments and trends in cloud computing are causing organisations to consider centralised, virtualised or streamed and hosted (outsourced) options such as Hosted Shared Desktops described in table 4.

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Compute Model 4: Hosted Shared

Desktop

Hosted shared desktops provide a

locked down, streamlined and

standardised environment with a core

set of applications, ideally suited for

Information workers where

personalisation is not needed – or

allowed. Supporting up to 160 users on

a single 16 core 64 bit server, this

model offers a significant cost savings

over any other virtual desktop

technology.

Usage: Ideal for Information workers

Mobility Autonomy Business Process Collaboration

2 3 2 3

Table 4. Hosted Shared Desktop compute model example

The function of mapping a user model to a compute model results in a positive or negative result. If all dimension values for the compute model are equal to or greater than the requirements expressed in the user model dimensions, then the mapping is positive, otherwise the mapping is negative. Mapping Compute model 4 (table 4) results in a positive mapping for Information Worker and Offline Information Worker. These positive mappings are shown in table 5.

User Model (Work Style) Mobility Autonomy Business Process Collaboration

Information Worker 2 1 2 3

Offline Information Worker 1 1 1 2

Mobile Knowledge Worker 6 4 4 6

Knowledge Worker 2 5 6 5

Table 5. Example user model to compute model mapping

The results from the mapping process will be tested against the expectations of a focus group. the stakeholders of the focus group would include the organisation management, representative members of the organisation and Capgemini. The requirements represented by the characteristics can be adjusted and the analysis re run taking into account the revised requirements from the end user focus group.

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3.5 Evolution

Following the implementation of the 'to-be' system the whole system can then be re tested to check for improvements in the quality of end user experience and improvements in energy intensity from the organisations computational systems.

4. TOWARDS A USER CENTRIC RENEWABLE ENERGY ASSESSMENT

TOOLKIT

The application of a multi criteria decision support system for residential renewables has been investigated previously (Alanne 2007). This case study will add to the existing body of work by analysing the system proposed in this paper in terms of requirements engineering. This new system will be similar to the desktop compute model case study, however instead of energy intensity it will evaluate reductions in the Kaya 'factor' of carbon intensity. The two systems differ also in that the renewable energy assessment is a user centric assessment as opposed to the desktop compute assessment which provided a global assessment of the enterprise.

4.1 Elicitation

In order for domestic electricity consumers to evaluate the optimum approach to reducing the carbon intensity of the energy they use, one option would be for the users to evaluate the feasibility and potential of producing their own micro-generation renewable energy. However these systems have different capabilities and performance criteria. The second case study of this paper aims to find an approach to enable the user to decide which system to choose. Voivontas et al. (1998) in their study which investigated the use of Geographical Information Systems (GIS) in a decision support system to assess the renewable energy potential on the Greek Island of Crete, describe a four dimensional assessment tool;

1. Estimation of the existing renewable energy systems potential 2. Assessment of the influence of local characteristics 3. Evaluation of the restrictions imposed by the available technology 4. Assessment of the expected economic profits 5.

These four dimensions are similar to the Gartner dimensions utilised in the previous case study. To align these more closely to our desktop model assessment tool these could be called; Power, Location, Autonomy and Cost. Descriptions are given in table 5 below

2

Dimension Description

Power Power capability of the system (1 = low power, 6 = high

power)

Location

Requirements of the energy model in terms of site, i.e,

wind energy requires high wind speeds and low

turbulence. (1 = specific location, 6 = any location)

Autonomy Reliability, maintenance, connection to grid

(1 = <90% reliable, 6 = 99.97% reliable)

Cost Alanne (2007) states that cost is a key factor in a DSS for

renewable energy (1 = low cost cost, 6 = high cost)

Table 5. Micro renewable energy assessment dimensions and their descriptions

4.2 Evaluation

As in the desktop compute model assessment, after defining the model dimensions, the next stage is to develop a questionnaire to map the energy requirements of the user to the capabilities of the assessed models. The user characteristics gathered from the questionnaire will be divided and condensed into the four dimensions from table 5. The user centric approach of this second assessment method negates the need for a generic set of user models, instead the user model would be customised directly to the requirements of the user and would be mapped directly to the energy models. The location dimension of the energy model assessment would involve the use of a geographical information system (GIS) model that could identify potential opportunities for communal district power and heating schemes whilst analysing wind speed potential for wind turbines.

4.3 Specification

In this user centric case study, the user models are specific to each user, unlike in a large organisation where it is not possible to deeply elicit the individual needs of every user so that generalisations are not necessary in the case study for domestic energy. Although some criteria may be gained by generalisation, such as the specific energy requirements of a device in a household due to the available granularity of the elicited requirements from the user. The end user of the decision support system will have one requirement document model describing their requirements with a 'score sheet' detailing the most appropriate micro renewable energy model.

4.4 Analysis

The user models will be applied to a set of micro renewable energy models. Table 6 defines 6 possible renewable energy models

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Wind turbines Plant Microbial fuel cells

Micro CHP Ground Source Heat Pumps

Photovoltaic solar systems Green supplier

Table 6. Energy models

As in table 5, having elicited the requirements of the users it should be possible to

map the positive domestic renewable energy options.

4.5 Evolution

It is intended that this assessment tool will link with the research output from aspect 02 (crowd sourcing) in order to enable communities to achieve renewable energy solutions such as district heating or 1MW wind turbines by operating collectively.

5. DISCUSSION

The requirements elicitation phase is constrained by the cost and disruption implications in the desktop compute case study assessment, in contrast to this scenario, the energy model assessment is user centric and would be triggered by interest from the user. The motivated user is more likely to respond positively to deeper questioning, this provides the energy model assessment with an advantage. However the compute model assessment counters this advantage because it can automate a large proportion of the requirements requests due to its highly granular information and performance monitoring systems. The energy model does not have such a sophisticated information model. As an example, in the compute model we can know the precise usage and name of every application on the desktop, however we cannot currently identify device usage in a building.

An approach for the elicitation of a high granularity energy profile of a user from an enery system would be useful to this research. The initial case study has four dimensions in response to the Gartner report (Gammage and Basso, 2009). this number is also used in the Voivontas et al. (1998) study. It was therefore decided to use 4 dimensions in the proposed renewable energy assessment. Along with the number of dimensions and their criteria, there is also a need for further investigation into the weighting of the user characteristics and their relationship to their dimensions. Finally, the algorithm used to map the user model to the energy model may need future work, in order to consistantly satisfy the conflict relieving requirements of the RE process at the evaluation stage.

6. CONCLUSION

This paper demonstrated the possiblity of constructing a generic toolkit that could be applied to two different challenges. The assessment methods are respectively interested in energy and carbon intensity, however these values are not explicitly expressed in the dimensions, this could be addressed with the addition of a fifth dimension. Both assessment methods are currently awaiting extensive testing in order to assess the validity of the approach and the relevance of the design

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assumptions. For instance it would be useful to compare users ability to find the optimum model without the use of the proposed tool.

It is intended that this toolkit will provide the first aspect of the SCD framework. This example took a tool from the domain of enterprise architecture and applied it to the challenge of a residential micro renewable energy supply decision. This process highlighted the underdevelopment of the energy system as an information system, i.e. in the compute model case study, detailed information can be gathered on the application inside the desktop and the processes inside that application, however in the energy example it is difficult to gather the same scale of information on the devices inside a property. This indentifies that there is potential for a more granular information model of our energy model. This result provides an idea of the potential of the approach of this research to apply solutions from enterprise architecture to the sustainability challenges posing the built environment. In future work, the research output for aspect 2 (crowd sourcing) would provide a participatory tool kit to form ad hoc networks that would enable the users of the aspect 01 energy model tool kit to form groups and work collectively to build district heating systems or 1MW wind turbines.

REFERENCES

Alanne, K. Salo, A. Saari, Gustafsson. S.I. (2007) Multi Criteria Evaluation of Residential Energy Supply Systems, Energy and Buildings, Volume 39, Issue 12, December 2007, Pages 1218-1226

Bell, T.E. Thayer, T.A. (1976), Software Requirements: are they really a problem?,

Proceedings of the 2nd international conference on Software engineering, p.61-68, October 13-

15, 1976, San Francisco, California, United States

Gammage, B. Basso, M. (2009), Segmenting Users for Mobile and Client Computing, G0016951916, Gartner, Inc. September 2009

IPCC, (2007), Summary for policymakers. In: Climate Change 2007: Mitigation. Contribution of Working group III to the fourth report of the Intergovernmental Panel on Climate Change [B. Metz, O.R. Davidson, P.R. Bosch, R. Dave, L.A. Meyer (eds)], Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

Kaya, Y. (1990), Impact of Carbon Dioxide Emission Control on GNP Growth: Interpretation of Proposed Scenarios. Paper presented to the IPCC Energy and Industry Subgroup, Response Strategies Working Group, Paris.

Peças Lopes, J.A. Hatziargyriou, N. Mutale, J. Djapic, P. Jenkins. N (2007). Integrating

distributed generation into electric power systems: A review of drivers, challenges

and opportunities, Electric Power Systems Research 77 1189–1203

Rogner, H.-H., D. Zhou, R. Bradley. P. Crabbé, O. Edenhofer, B.Hare (Australia), L. Kuijpers, M. Yamaguchi, (2007): Introduction. In: Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [B. Metz, O.R. Davidson, P.R. Bosch, R. Dave, L.A. Meyer (eds)], Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

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Voivontas, D. Assimacopoulos, D. Mourelatos, A. Corominas, J. (1998) Evaluation of Renewable Energy Potential using a GIS Decision Support System, Renewable Energy, Vol. 13. no. 3, pp 333 - 344

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WBCSD, (2009): Energy Efficiency in Buildings: Transforming the Market. World Business

Council for Sustainable development

WHO, (2005): 2005 World Summit Outline Document. World Health Organisation, 15

September 2005

13



Selecting Key Performance Indictors (KPIs) for Sustainable Intelligent

Building

H. Shah1*, S. Gulliver2, K. Liu3, J. Sharvell4

1Technologies for Sustainable Built Environments, University of Reading, UK 2,3Informatics Research Centre, University of Reading, UK

4Central Data Control Ltd, London, UK


ABSTRACT

Environmental concerns and the continual drive for energy efficiency in buildings,

has led industry to look more closely at sustainable development and the

sustainability of existing buildings. The majority of building environmental

performance assessment methods developed today, involve a building meeting, or

satisfying, pre-defined standards and requirements. Improvements to a building’s

environmental performance are usually ascertained by first benchmarking the

current set up. In order to do this it is necessary to identify and understand specific

building key performance indicators (KPIs). Selecting the most suitable KPIs,

particularly when building systems are intelligently managed, can be both

challenging and critical to the assessment of a building’s environmental

performance.

This paper assesses some of the current practices and advances in building

environmental performance assessment. It also considers how benchmarking and

semiotics approaches may be integrated with current environmental assessment

methods to more accurately measure the impact of users and building use.

Keywords:

Key Performance Indicators, Sustainability, Environmental assessment, Building,

Semiotics.

1. INTRODUCTION

Nearly half of the energy currently consumed in the UK, is used in buildings

(Energy policy, 2010). Therefore, improvements in a building’s energy performance

can significantly reduce energy consumption and hence contribute to a more

sustainable energy economy. Sustainable development is most commonly applied to

new buildings, and attempts to introduce more effective, materials, technologies

and practices. Sustainability of existing buildings, however, is more difficult since it

is necessary to live with known building deficiencies and accept the fact that not



13

everything can be economically modernised.

The energy performance of a building depends on its architectural design, and

functional use. Considerations concerning the design of a building usually only

apply to new builds. As a result the UK government has set targets of zero carbon

for all new residential and commercial buildings by, 2016 and 2019, respectively.

However, 70% of the buildings that will be around in the year 2050 have already

been built (Energy policy, 2010). Accordingly focusing simply on improving the

performance of new builds will, on its own, have limited impact. Assessment of

existing buildings, which often contain wasteful technologies, and the effective

improvement of energy performance in these buildings, is critical to achieving

sustainability. Figure 1 identifies the general paradox that implementing

sustainable new buildings are easier for developers, however more costly and more

disruptive to organisations.

Figure 1: Considerations to building energy performance

Research conducted by Foresight (2009) shows that building usage has a

considerable impact on the overall energy usage. Mackay (2008) argues that minor

changes in the way we live and work, such as simply switching off something that

does not need to be on or replacing high energy equipment with more efficient

alternatives, can bring about significant energy savings. The impact of minor

changes in large building systems usually means that considerable energy

performance improvements can be gained. A building system usually consists of

sensors, actuators, communication networks and a central server. Common

building systems in ‘intelligent buildings’, along with their function, is shown in

Table 1.

Table 1: Common building systems in ‘intelligent buildings’ and the role they

play.

BUILDING SYSTEM FUNCTION

Building Management Systems (BMS) -Overall building management

Heating, Ventilation and air conditioning

(HVAC)

-Controls indoor air quality and comfort

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Addressable Fire Detection and alarm (AFA) -Fire prevention and incident handling

Telecommunications and Data systems (ITS) -Handle all digital communications

Security Monitoring and Access (SEC) -CCTV surveillance and access control

Digital Addressable Lighting Control (DALI) -Efficient Control of lighting

Smart Lift Systems (LS) -Efficient management of lifts

Comp. Maintenance Management System

(CMMS)

-Managing inventory and service works

Due to the often high level of complexity in intelligent buildings, and the large

potential number of measurable factors, appropriate changes to building energy use

can only be realised if the critical factors in building systems are first identified. In

the following section we introduce the area of Key Performance Indicators, which

aims to highlight critical factors impacting specific building performance.

2. KEY PERFORMANCE INDICATORS

Key Performance Indicators (KPIs) are quantifiable measurements, selected

beforehand, that are defined as key to benchmarking success. It is critical to limit

the number of KPIs to include only factors that are essential to the building’s goals.

Continuous monitoring of the KPIs can help identify the progress being made

towards a predefined goal set.

Various building performance assessment methods have been developed to assess

building environmental performance. These methods usually provide a framework

or a set of good practices that should then be followed within the operation of the

building. Building performances are then measured and compared against the

defined best practices, with distinction being made for new and existing builds. As

it is too time consuming to assess everything that is measureable within a building,

building performance assessment methods need to first identify the KPIs that are

specific to the specific building. These are the variables that have the most

significant impact on the performance of that particular building, since KPIs can

vary significantly depending on a building’s location, climate, government

legislation, usage, etc.

As the choice of KPIs impacts assessment results, selecting the most appropriate

KPIs is a big challenge. The following section expands upon current methods used

for assessing building KPIs.

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3. CURRENT BUILDING PERFORMANCE ASSESSMENT METHODS

Building performance assessment methods and tools are being developed

worldwide (see table 2). These methods assess how well a building is performing, or

is likely to perform. If properly applied, it can provide a useful set of tools to

identify KPI and monitor improvements in the building’s environmental

performance (Clements-Croome, 2006). Building performance assessment methods

have helped define many emerging sustainability concerns and have provided a

way of communicating this with the building stakeholders.

Figure 2: Process of BREEAM (BREEAM, Fact File, 2007)

BREEAM (Building Research Establishing Environmental Assessment Method) is

currently the most widely used environmental assessment method for buildings

within the UK (BREEAM, Fact File, 2007). BREEAM sets a weighting for each

criterion to reflect its importance and significance (see figure 2). Sometimes,

buildings can achieve unusually high scores, despite scoring poorly in a few key

areas. In this case sustainability can be viewed as an average performance rather

than a series of satisfied criteria, which risks ignoring the impact of specific factors.

BREEAM, along with all other assessment tools, have the weakness that they are

only applied on a voluntary basis. Despite common acceptance, BREEAM also fails

to support full life-cycle analysis for buildings.

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Table 2: Current Environmental Performance Assessment Methods

METHOD DETAILS

BREEAM (Building Research Establishing Environmental Assessment Method), by Building Research Establishment Ltd., UK.

Assess the environmental performance of both new and existing buildings.

HK-BEAM (Hong Kong Building Environmental Assessment Method), by Hong Kong Environment Building Association, Hong Kong, China.

Based on BREEAM, considered the local situation and government policies to give the guidelines and certifications on building environmental performance.

LEED (Leadership in Energy and Environmental Design), by Green Building Council, U.S.

Voluntary, updated every 5 years. US National standard for developing high-performance, sustainable buildings.

CASBEE (Comprehensive Assessment System for Building Environmental Efficiency) by Sustainable Building Consortium, Japan.

Introduced to meet both the political requirements and market demands for achieving a sustainable society through building life span.

IBI 3.0 (Intelligent Building Index: Manual Version 3.0), by The Asian Institute of Intelligent Buildings, Hong Kong, China,

Based on political requirements, construction industry needs and building users’ demands of buildings

GB Tool (Green Building Tool) by International Team (Canada, USA, etc.)

Software developed as part of the international green building challenge process, updated accordingly, and still under development

Current building performance assessment methods can be generally split into two

categories:

1. Based on criteria and weighting system – e.g. BREEAM (UK). 2. Use a checklist of each building performance aspect - e.g. LEED (US).

Many of the current building performance assessment methods make use of

multiple steps to build a benchmarking framework. Initially performance indicators

are discovered using surveys, questionnaires, interviews etc. Then KPIs are selected

by senior managers and/or a panel of experts, thus compiling a list of KPIs

according to their knowledge and experiences. Finally, the relative importance of

each KPI is defined by making use of an Analytic Hierarchy Process (AHP) or

Analytic Network Process (ANP). One problem with this process is that even though

the decision-makers are all experts, the results can sometimes be very subjective

(Wong et al, 2008). To avoid this, a concerted effort must be made during the

process of selecting KPIs to be objective and clear, whilst also including all building

stakeholders.

The specification and validation of key performance indicators is essential to the

fair assessment of how a building impacts its environment. Current subjective

13

judgement makes it hard to understand the impact of qualitative factors, such as

social, cultural and organisational aspects of building use, which, although having a

decisive role in the ultimate sustainability of the building, can be hard to quantify

or formalise. In sections 4 and 5 we introduce discussion concerning benchmarking

and semiotics, which we propose should be integrated in support of current

assessment methods to facilitate a more accurate assessment of KPIs relating to

building users and building use.

4. BENCHMARKING IN BUILDINGS

Benchmarking enables building managers and stakeholders to quantify and

compare building environmental performance. Benchmarking has been identified

as an important measurement tool for identifying improvements (Eaton, 2002).

Eaton (2002), using such phrases as ‘fulfilling needs’, ‘suitable for use’ and ‘fitness

for purpose’, states that: in construction, it is a common practice to define quality

in relation to performance as ‘the degree to which performance matches

requirements’. Fisher (1996) stated that benchmarking therefore plays a key role in

underpinning performance, and, in the construction industry, is a systematic way

of evaluating the inputs and outputs in manufacturing operations or construction

activity, and therefore acts as a tool for continuous improvements. Benchmarking

also supplies tools for assessing the impact of change within existing building by

means of performance indicators, however this benchmarking demands a clear set

of building requirements; which is perceived as being hard to achieve when

considering social, cultural and organisational aspects of use.

Cordero (1990) proposed a model of performance measurements in terms of

outputs and resources to be measured at different organisational levels, but it failed

to reflect the interests of stakeholders, their needs and expectations. The occupants

of the building are the people that best understand most aspects of the building use

and performance, however very few organisations ask their staff whether the

building meets their requirements. Environmental assessment, instead of relying on

management and ‘expert’ feedback concerning intended building use, should

consider the real-world relationship between the building and its occupants. Sadly,

however, analysis of social, cultural and organisational dimensions are often

ignored as semantic, pragmatic and social analysis is perceived as being both

complex and unable of delivering a formalised set of requirements for use with

benchmarking. In section 5 we introduce organisational semiotics, which offers

potential methods for problem articulation, and semantic and norm analysis of

building KPIs.

5. ORGANISATIONAL SEMIOTICS

Organisational Semiotics (OS) is the study of organisations using the concepts and

methods taken from semiotics (OSW, 1995). Using OS, environmental assessment

should be able to consider the relationship between the building occupants, the

building processes (i.e. use), and the building technology (i.e. both the physical

13

building structure and use of material, but also the legacy integrated technologies).

It can be argued that OS can: facilitate clarity when identifying user building

requirements; allow environmental consideration of user pragmatic intention

within the building; and identify limitations or omissions of current KPI or

information capture. In this work, we suggest the application of the Problem

Articulation Method (PAM), the Semantic Analysis Method (SAM) and the Norm

Analysis Method (NAM), to the problem of building KPIs. PAM, SAM and NAM are

methods, defined by Stamper et al (2000) as part of MEASUR (Methods for Eliciting,

Analysing and Specifying User’s Requirement), which would support the capture of

social, cultural and organisational KPIs relating to building use. In the following

sections we will introduce each of these methods in turn, and conclude by asking

whether the MEASUR methodologies could be integrated with current environment

assessment methods to consider requirements of building users, building intention

and use, as well as the KPIs of emerging building intelligence systems.

Problem Articulation Method (PAM)

PAM consists of methods that are normally applied when the problem definition is

still unclear. PAM is composed of: Stakeholder Analysis, Valuation Framing and

Collateral Analysis (see figure 3); and in essence gets key stakeholders to define

issues using Stamper’s Semiotics ladder (Liu, 2000) - see figure 4.

13

Human

Information

SOCIAL WORLD beliefs,

expectations, functions,

commitments, contracts,

law, culture, …

PRAGMATICS intentions,

communications,

conversations, negotiations, ...

SEMANTICS meanings,

propositions, validity, truth,

signification, denotation, ...

IT SYNTACTICS formal structure,

language, logic, data, records,

deduction, software, files, …

EMPIRICS patterns, variety, noise,

entropy, channel capacity, redundancy,

efficiency, codes, …

PHYSICAL WORLD signals, traces,

physical distinctions, hardware,

component density, speed, economics, …

Figure 3. Adaption of the PAM methodology

to support determination of building KPI.

Figure 4. The semiotic framework

(Stamper, 1996).

Stakeholder analysis allows definition of those with direct or indirect influence over

the building energy use. The clarification of stakeholders in context of building

operation, contribution, source, market and community, allows the systematic

checking of building use and user identification of stakeholder interests in

valuation framing. Valuation framing allows interaction of stakeholder interests to

be identified, and for risk areas to be defined where no stakeholder currently claims

ownership. The semiotic framework places energy use in context of the semiotic

ladder (see figure 4), which shows the stakeholder that energy use is significantly

impacted by both structural and human indicators. Collateral analysis allows

analysis of the interaction between factors that impact building energy use. This

supports clarity concerning the interaction of building use, as well as its impact on

environmental factors, which is commonly ignored in other assessment methods.

Semantic Analysis Method (SAM)

SAM takes the defined problem, possibly defined as an output of PAM, and

formalises the requirements. With the help of a facilitator, building environment

13

requirements can be defined within a related ontology model, to describe energy

use from specific dimensions. This formalised set of requirements can act as the

basis for semantic KPI benchmarking.

Norm Analysis Method (NAM)

A norm is the modelling of a behaviour pattern that is regarded as typical. NAM

allows the capture of general behaviour patterns, by analysing behaviour

regularities. Creation of norms allows us to assess the impact on energy use of

social, cultural and organisational factors; factors that are often unrelated to the

physical building structure. The other main advantage of using norms is it supports

the allocation of responsibilities; an essential step in ensuring long term

sustainability.

5. CONCLUSIONS

New and existing buildings are increasingly faced with the challenge of being as

sustainable as possible. The process for selecting the Key Performance Indicators

(KPIs), for use with performance assessment in buildings, is both technical and

complex. The building environmental performance assessment method is used to

quantify how ‘environmentally friendly’ or ‘sustainable’ a building is determined as

being. The identification of KPIs supports the use of benchmarking and adapts it to

the sustainability challenges of the construction industry. Building stakeholders

have to be actively involved to assess their own performance, productivity rates,

cost estimations, etc. Moreover, building users have to also be more open to

benchmarking practices that have been successful in other industries, and adapt

them to the construction industry. Benchmarking should be considered as a part of

an ongoing process aiming at continually improving building environmental

performance.

The semiotics approach for modelling semantics in building environmental

performance assessment would certainly help in the selection of more user-centric

KPIs. This approach can help to form the framework of an improved methodology

for assessing the sustainability of a building. The outcomes of a semiotics approach

should be of importance to all the building stakeholders. This semiotics approach

can also be used as a tool by architects to communicate sustainability issues during

the early stages of design. Building users can have access to reliable information

about the sustainability performance of a building before purchase, or even before

construction. The semiotics methodology has the potential to be used for

sustainability certification for buildings.

Building environmental performance assessment methods should be designed for

easy implementation and therefore not necessitate a great deal of technical

expertise from the building users. The selection of KPIs still remains the most

challenging aspect of environmental performance assessment and inevitably affects

the integrity of the end results. A semiotics approach, although needing further

research, in practice forms a basic framework upon which other standards can be

built. A worldwide accepted assessment methodology is still a long way off,

13

however convergence of established methods provides the greatest chance of wide

spread acceptance.

As building systems become more integrated and building management systems

become more intelligent, appropriate capture of building KPIs is essential to ensure

sustainability, via effective building assessment and profiling, user feedback.

Although additional research and validation is required, we believe the

consideration of social, cultural and organisational KPIs are critical to achieving

sustainability in both new builds and existing modifications.

ACKNOWLEDGEMENTS

The authors wish to thank fellow researchers at the IRC and John Sharvell of CDC

(UK) for their clarification on the subject of Semiotics and building systems,

respectively.

REFERENCES

BREEAM (2007), BREEAM fact file [online]. Available from:

http://www.breeam.org/filelibrary/breeam_Fact_File_V5_-_Oct_2007.pdf

[Accessed 11 June 2010].

Clements-Croome, D.J et al. (2006), Creating the Productive Workplace. London: Taylor &

Francis.

Cordero, R. (1990), The measurement of innovation performance in the firm: An

overview.

Research Policy, Volume 19, Issue 2, April 1990, pp 185-192

Eaton, D. (2002), Benchmarking. In Kelly, J., Morledge, R. and Wilkinson, S. (Eds.),

Best Value in Construction. London: Blackwell Publishing, pp. 59-76.

Energy Policy (2010), Published by Elsevier Ltd. www.elsevier.com/locate/enpol

accessed on 20th June 2010.

Fisher, J. G. (1996), How to Improve Performance through Benchmarking? London: Kogan

Page Limited.

Foresight’s Sustainable Energy Management and the Built Environment (SEMBE)

Project. Presentation 24 April 2009. www.foresight.gov.uk accessed 5th June

2010

Liu, K. (2000), Semiotics in Information Systems Engineering. Cambridge: Cambridge

University Press.

MacKay D. J. C. (2008), Sustainable Energy - Without the Hot Air. Chapter 22:

Efficient electricity use. UIT Ltd.

OSW: The circulation document. Organisational Semiotic Workshop. Enschede

(1995), apud Liu, K.: Semiotics in Information Systems Engineering. Cambridge

University Press.

Stamper, R.K. (1996), Signs, Information, Norms and Systems, in Holmqvist, P.,

Andersen,

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V77-45D17BM-M&_user=8891456&_coverDate=04%2F30%2F1990&_alid=1381235829&_rdoc=11&_fmt=high&_orig=search&_cdi=5835&_st=13&_docanchor=&_ct=12&_acct=C000017279&_version=1&_urlVersion=0&_userid=8891456&md5=da8adc17a239b2c7e3c0e545f964af03

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Stamper, R., Liu, K., Hafkamp, M. and Ades, Y. (2000), Understanding the roles of

signs and norms in organizations – a semiotic approach to information systems

design. Behaviour & Information Technology, 19(1), pp. 15-27.

Wong J., Li, H and Lai, J., Evaluating the system intelligence of the intelligent

building systems: Part 1: Development of key intelligent indicators and

conceptual analytical framework. Automation in Construction, Vol. 17, Issue 3, March

2008, Pages 284-302

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V20-4P8H889-1&_user=8891456&_coverDate=03%2F31%2F2008&_alid=1381246555&_rdoc=7&_fmt=high&_orig=search&_cdi=5688&_sort=r&_docanchor=&view=c&_ct=65&_acct=C000017279&_version=1&_urlVersion=0&_userid=8891456&md5=6f1dde8bd7a5463d642330e8ca27cf9a



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Use of Soft Measures to Reduce Private Vehicle Use Among Commuters

M. H. Ismail1*, J. Doak2, C. Pickles3

1 Technologies for Sustainable Built Environments, University of Reading, UK 2 School of Real Estate & Planning, University of Reading, UK

3ESG Herefordshire Limited, Hereford, UK


ABSTRACT

The paper conducts a detailed analysis of the currently available soft measures

which can be implemented by employers and/or the local authority via a

‘workplace travel plan’ to reduce private vehicle use by employees in their

commute to work. The paper considers the social, economic and environmental

impacts of each of the measures as well as political implications, namely the need

for local authority involvement for the success of such soft measures. The paper

also discusses which measures it considers key to a successful workplace travel

plan, including parking restrictions and provision of workplace bicycle parking and

shower facilities, and concludes by considering the potential risks to successful

implementation of workplace travel plans, such as public spending cuts.

Keywords: Workplace Travel Planning; Soft Measures

1. INTRODUCTION A key part of developing a sustainable urban transport system as part of a

sustainable built environment involves measures to reduce private vehicle use and

increase use of public transport, walking or cycling instead. The overall objective of

such action is to achieve the following benefits:

Reduced carbon emissions from transport

Reduced traffic congestion (leading to improved quality of life and improved

local economy)

Improved air quality (leading to improved quality of life and public health

benefits)

Improved health (from increased walking and cycling)

One method to achieve these aims involves ‘soft’ transport policy measures, which

aim to encourage people to make “smarter choices” in relation to transport use

(Cairns et al, 2004), to choose public transport or other sustainable transport modes

instead of their private vehicles.



13

Although soft measures do not in themselves involve physical changes to urban

infrastructure or investment in new operations or technology, it is self-evident that

measures cannot be taken to encourage a modal switch to public transport use if

there is no effective public transport system in operation. Therefore, local

authorities would be wise to ensure that a safe, efficient and effective public

transport system exists in the area before committing to the use of soft measures to

encourage increased public transport use.

The paper will focus on soft measures aimed at commuters to work, as the daily

commute contributes significantly to morning and evening traffic congestion. Soft

measures which can potentially apply to commuters can be most effectively

implemented as a bundle of measures within a ‘workplace travel plan’ – set up by

the employer (but often instigated or encouraged by the local authority).

2. AVAILABLE MEASURES

Soft transport policy measures targeting commuters may be implemented by the

employer independently or working together with the local authority. These

measures can be organized collectively into a workplace travel plan. Key measures

include:

2.1 Controlling Parking

Typical methods for controlling parking may include:

2.1.1. Reducing the Number of Workplace Parking Spaces Available

This may arise from commercial considerations (i.e. cost savings from reduced

rental or maintenance costs) or policy factors (such as the new workplace parking

levy to be introduced in Nottingham affecting employers with more than 10

parking spaces5). However, for any restrictions made by the employer on its own

premises to be effective, the local authority would need to similarly establish strict

parking control in the areas surrounding the employer’s site, including limiting the

length of stay to short periods (1 to 2 hours) and/or increasing parking charges to

encourage short stays only. Naturally, exceptions must be made for disabled users.

2.1.2 Allocation

This involves allocating the convenient spaces for customers/clients and leaving

more distant spaces for employees. Again, such parking control may arise from

commercial considerations, in ensuring maximum convenience to customers and

clients to the disadvantage of employees, rather than considerations of sustainable

travel planning.

2.1.3 Incentives to Give Up a Space

5 Refer to the Nottingham City Council website for further detail: www.nottinghamcity.gov.uk

13

2.1.4

Shoup (1997) found that offering cash allowances instead of a free parking space

reduced the number of people travelling alone to work by between 3% to 22%.

2.1.4 Discussion

It has been reported that workplace travel plans which include some element of

parking restriction reduce commuter car use by an average of 24% or more, whilst

those workplace travel plans which do not include any element of parking

restriction reduced commuter car use by an average of 10% or more (Cairns et al,

2004). However, the effectiveness of parking restrictions in reducing commuting

car use could be limited if plentiful low cost parking is readily available near the

employer’s workplace.

From a social perspective, it may be inappropriate to impose additional cost or

inconvenience on employees by way of parking restrictions if public transport

provision is poor in the area – for example if the workplace is based in a remote

site. In addition, exceptions will be necessary for disabled employees.

However, as commuters who are used to driving may not switch to public transport

use without a significant ‘push’ factor (regardless of the quality of the public

transport available), it is considered that parking restrictions are an essential

workplace travel planning strategy.

2.2 Public Transport Initiatives

2.2.1 Season Ticket Loan

Employers may assist the employee in purchasing a public transport season ticket

(and therefore benefit from the discounted rates available) by purchasing the season

tickets on behalf of the employee then deducting the cost of the ticket from the

employee’s usual pay.

2.2.2 Reduced Public Transport Charges

Large employers may be able to negotiate reduced rates with public transport

providers for their employees, although local authorities may be able to negotiate

more effectively. For example, Birmingham city council can offer a 50% discount on

an annual public transport season ticket for employees of companies affiliated to

the Company TravelWise scheme, on the condition that the employee gives up

driving to work6.

6 Refer to the Birmingham City Council website for further details: www.birmingham.gov.uk/travelwise

13

2.2.3 Guaranteed Ride Home

Employers may consider guaranteeing employees who use public transport a free

taxi home should work require them to stay too late to catch a bus or train home in

exceptional circumstances.

2.2.4 Discussion

These strategies are likely to be popular with employers, in particular in relation to

offering discounted season tickets to staff, as they are low cost and place little

administrative burden on the employer, whilst providing a significant benefit to

employees. Therefore, as well as the environmental benefits of encouraging

reduced car use, there are economic and social advantages for the employer in

assisting it to retain its valued employees. However, again, the available public

transport must be efficient, safe and comfortable, otherwise employees will not

wish to utilise it in any event.

Offering public transport discounts has been reported to be highly effective as a

‘pull’ factor to encourage reduced car use (Cairns et al, 2004) so it is considered that

public transport discounts would be a highly desirable strategy to implement into

workplace travel planning.

The other strategies (season ticket loan and guaranteed ride home) are unlikely to

be determinative factors in encouraging employees to switch to public transport

use, so although they may be useful, they are not essential workplace travel plan

elements.

2.3 Walking or Cycling Initiatives

2.3.1 Bicycle Parking and Shower Facilities

To encourage employees to walk or cycle to work, employers may provide bicycle

parking and shower units. The Victoria Transport Policy Institute recommends the

following features of long-term bicycle storage for employees:

Located on site or within 750 feet of site

Secure area (locked or monitored by security guard/security cameras, or

within view of employee work areas)

Protected from weather (50% indoors with overhangs or awnings to protect

outside bikes from rain and sun)

Suitably spaced (typically 2 x 6 feet per bike with a 5 foot wide aisle)

Well-signposted if not immediately apparent

The cost of installing bicycle parking units varies according to the quality and style.

Transport for London indicates that Sheffield Stands are the most common type of

bicycle stand, and cost in the region of £35 to £100 per stand, with each stand

13

securing two bicycles. Transport for London recommends 1 bicycle stand for every

250m2 of office space (Cycle Parking Standards, TfL Proposed Guidelines).

From an environmental perspective, such facilities are essential, as employees are

unlikely to cycle to work without them. From social or economic perspectives,

these facilities are useful in maintaining good employee morale among those who

wish to cycle or walk to work, but are unlikely to be crucial in staff retention.

Due to the relatively low cost involved and their essential nature for cyclists to

work, it is considered that such schemes form an essential part of any workplace

travel plan.

2.3.2 Bicycle Hire-Purchase Schemes

Such schemes involve employees purchasing expensive bicycle equipment via

monthly instalments deducted from their salaries. There may be tax incentives for

the employee, as well as the benefit of paying by instalments, whilst there is no

cost for the employer.

2.4 Worksite Amenities

Providing facilities such as workplace canteens or on-site childcare can assist

employees who need their private vehicle for personal trips before or after work or

at lunchtime, particularly if the employer’s site is in a remote area. Such facilities

will involve initial capital expenditure but can be cost-effective if popular. The

implementation of such worksite amenities will often be for commercial purposes,

such as attracting and retaining the best staff and improving employee morale. It is,

perhaps, unlikely that an employer would provide such facilities solely for travel-

planning considerations. These measures could be considered on a case by case

basis, taking into account the surrounding facilities around each local employer.

2.5 Car Share Schemes

This involves individuals sharing a car for the same journey, and is therefore ideal

for employees commuting to the same workplace or business park. Employers

could assist with the marketing or administrative aspects of running the scheme

(such as matching prospective car sharers together based on their home address), at

low cost and low administrative burden.

This strategy is a useful part of any workplace travel plan, although is lower priority

compared with the Parking and Public Transport strategies.

3. COSTS

Table 1 below sets out the potential costs in relation to each strategy. The results of

the table indicate that some workplace travel plan strategies can be implemented

by employers at little annual cost. Cairns et al (2004) found that the median annual

running cost of a workplace travel plan was £47 per full-time equivalent employee.

13

Schreffler (1996) found that transportation demand management programmes cost

in the region of $30 per employee.

However, even at low cost, employers may be unlikely to invest the administrative

time and effort to implement workplace travel planning merely for the

environmental benefits of reducing car use among their employees. As highlighted

above, many of these strategies have economic or social considerations as well, and

these may be more likely to be the deciding factors as to whether or not the

strategy is implemented.

Therefore, local authorities often become involved in encouraging (or requiring)

employers to implement particular strategies to benefit the local area from an

environmental, economic, social and political perspective. However, local

authorities would need to balance the importance of implementing the measures

against the risk of placing too onerous a burden on local employers which could

adversely impact on the economic competitiveness of the region by driving away

existing or potential employers.

Table 1: Typical costs involved in different travel planning strategies

Strategy Cost

Income Neutral Outlay

1. Reduced car parking

£300 to £500 per parking space P.A. (Cairns 2004)

2. Car parking allocation

No cost

3. Parking charges

Income from charges

4. Financial incentives Cost-neutral7 5. Public transport

season ticket loan Minimal cost8

6. Reduced public transport charges

Cost-neutral9

7. Guaranteed ride home

Taxi fares on occasion.

8. Bicycle parking

£35 to £100 per stand

9. Shower facilities

Variable

10. Workplace amenities

Variable

11. Car share

Minimal cost10

7 This presumes that the financial incentive is no more than the £300-£500 saved from reduced parking spaces. 8 This is the small administrative cost in implementing the scheme. 9 Costs borne by public transport operator in return for increased custom or other commercial incentive. 10 This is the small administrative cost in implementing the scheme.

13

4. LOCAL AUTHORITY MEASURES

Cairns et al (2004) sets out a summary of how 7 local authorities11 have attempted

to encourage employers to develop workplace travel plans. Tactics used include:

4.1 Discounts on public transport

Birmingham has negotiated a 50% discount on a public transport annual season

tickets. York has negotiated a free 6 month bus pass to commuters.

Buckinghamshire has negotiated a 34% discount on train season tickets and a 50%

discount on bus season tickets.

4.2 Public Transport Information

Several local authorities provide timetables and journey planners to employers to

display to employees, then begin liaising with them in relation to implementing

travel planning.

4.3 Cycling initiatives

Several local authorities have negotiated discounts at cycling shops. Bristol provides

two bike racks per SME and offers 125 adult cycle training sessions per annum.

Cambridgeshire also runs adult cycle training sessions and offers grants for

installing cycle parking.

4.4 Walking initiatives

Buckinghamshire provides a walk-share scheme, to match people to walk a

particular route together. Merseyside provides local walking maps with information

as to calories burned on different routes. Nottingham has invested in pedestrian

route improvements.

4.5 Car-sharing

Several local authorities operate car share schemes.

4.6 Grants to fund travel plans

The largest grants offered were up to £20,000 from Nottingham and up to £5,000

from Bristol. Other local authorities offer smaller grants for specific items such as

bicycle parking.

11 Birmingham City Council, Bristol City Council, Buckinghamshire County Council, Cambridgeshire County Council, Merseyside local authorities, Nottingham City Council and York City Council.

13

4.7 Planning permission control

Birmingham requires, as a condition of planning approval for a development with

50 or more employees, that the company joins the Company TravelWise scheme.

However, other local authorities prefer that companies join voluntarily.

4.8 Commuter clubs

Several local authorities arrange focus groups between local employers to discuss

common local transport/commuter issues.

4. CONCLUSIONS

Use of soft measures within workplace travel plans can be effective in reducing

commuter reliance on private vehicles and encouraging a switch to public

transport, walking or cycling. However, for such measures to have a long-term

impact, local authorities must ensure that safe, efficient and adequate public

transport exist for commuters as an effective alternative to private vehicle use.

Without such an alternative, restrictions to private vehicle use (such as parking

restrictions) may be met with public outcry and dissatisfaction, leading to

movement out of the relevant region and reduced economic viability.

A current concern now is how the new Coalition Government’s proposals to

significantly reduce public spending will impact on the use of workplace travel

plans. In particular, spending cuts may mean insufficient funding in local

authorities to invest in maintaining and increasing the capacity of public transport

services, which could in turn deter local authorities and employers from investing

time and money into workplace travel planning.

REFERENCES

Cairns, S., Sloman, L., Newson, C., Anable, J., Kirkbride, A., Goodwin, P. (2004),

Smarter Choices – Changing the Way We Travel, Department for Transport

Schreffler, E. (1996), Effective TDM at Worksites in the Netherlands and the US,

Organizational Coaching

Shoup, D. (1997), Evaluating the Effects of Cashing Out Employer-Paid Parking:

Eight Case Studies, Transport Policy, 4(4) 201-216

Transport for London, Cycle Parking Standards, TfL Proposed Guidelines

Victoria Transport Policy Institute website: www.vtpi.org/tdm

http://www.vtpi.org/tdm

13



Bats and Breathable Roofing Membranes: Mechanical Stability of Membranes under Bat Usage Conditions.

S. Waring1*, R. Bonser1, K. Haysom2 1Technologies for Sustainable Built Environments, University of Reading, UK

2Bat Conservation Trust, London, UK


ABSTRACT

Biodiversity is an important part of sustainability within the built environment, and

bat conservation is a vital aspect of UK biodiversity action plans. Bats need safe

places to roost, and as modern agriculture, forestry and urban growth have reduced

the number of natural bat roost sites [1], the scarcity of suitable sites has forced

some species to seek alternative locations. Such shifts in roosting behaviour have

caused bats to become unusually dependent upon buildings, making them

vulnerable to re-roofing [2]. As many suitable roosts age, their roofs need replacing

and traditional roofing felts are frequently being replaced with breathable roofing

membranes (BRM’s). BRM’s typically comprise spun-bonded polymeric materials and

membranes. They are designed to improve energy efficiency of a building and

reduce condensation in roof voids. Preliminary evidence suggests that BRM’s could

pose an entanglement threat to bats.

Tests will be carried out within a laboratory setting and will aim to quantify the

wear and tear experienced within a bat roost. This will be done at a finer level than

the tests carried out by agreement certificates, to take into account the shape and

sharpness of claws found on UK bat species known to roost in buildings. I present

preliminary data on the claw characteristics of several British bat species and how

this will enable testing of commercially-available membranes.

INTRODUCTION

Bats need safe places to roost, and as modern agriculture, forestry and urban

growth has reduced the number of natural bat roost sites or made them less

suitable [1], the scarcity of suitable sites has forced some species to seek alternative

locations. Many of these new roosting opportunities are within buildings, where

species that traditionally roosted within cracks in trees, have adapted to use gaps

between timbers whilst cave dwelling bats have moved into slated roof spaces [2].

These shifts in roosting behaviour have caused bats to become unusually dependent

upon buildings and other man-made structures, for both breeding and hibernation.

This relationship has often brought difficulties and as a result bat populations

declined by nearly 90% during the 20th Century [2].



13

Because of this roost fidelity and the declining numbers of bats in the UK, all bats

and their roosting places (whether bats are present or not) are protected by two

major pieces of wildlife legislation:

1. The Wildlife and Countryside Act 1981 (WCA) [3]

2. The Conservation (Natural Habitats &c.) Regulations 1994 [4].

Reliance on buildings for roosting makes bats vulnerable to building repair work,

re-roofing and timber treatments [2].As many suitable roosts age their roofs need

replacing and a question regularly asked of the Bat Conservation trust is which, if

any, breathable roofing membranes are suitable for use in bat roosts? We do not

have an answer to this query. The issue continues to cause concern, with a number

of reported cases where bats have died after becoming entangled and trapped by

fibres that had been pulled loose. The aim of this project is to quantify the

difference in mechanical properties making them more or less amenable to bat

colonisation.

PROJECT BACKGROUND

In the past decade there has been an increasing interest in developments that have

given consideration to wildlife and how it interacts with adjacent natural areas and

the development itself. This has helped to improve the facilities which make up the

green infrastructure of a site. A good example is the use of Sustainable Urban

Drainage Systems and maintaining existing habitat features. But the importance of

the actual built structures themselves, to wildlife is often overlooked in both new

builds and more importantly existing buildings that are already in use by wildlife.

Importance of Buildings for Bats

All UK bat species will use buildings at some point, but for a few species they are

essential roost sites. They take advantage of a variety of buildings including the

roofs of domestic dwellings and barns that are often converted. Bats may be found

singly, in small groups or colonies throughout the year, though most commonly in

summer when some species form maternity colonies [5].

In temperate regions bats have to cope with long periods where prey is scarce. In

order to do this they reduce their energy needs by allowing their body temperature

to drop to that of their surroundings, this is known as torpor. But unless the

weather is very poor, pregnant females avoid torpor as it delays foetal development.

To reduce energy demands without the need for torpor they choose warm roosting

sites e.g. buildings [2]. Reproductive females of several species select roosts on the

basis of temperature [6-10], as temperature has been suggested as vital in

determining the quality of a bat maternity roost. It affects the energy costs required

to maintain a high body temperature, which in turn effects the growth rate of

embryos and young [11, 12]. Advantages for bats roosting in buildings (lower

predation risk, earlier births, faster juvenile growth rates, and increased energy

savings) lead to greater long-term reproductive success for building-roosting bats

and make buildings preferred roosts [13].

When bats use buildings, they usually conceal themselves in crevices, behind

roofing felt, in cavity walls or under ridge tiles [14]. Of the 16 UK species only the

13

two horseshoe bats, both rare and found only in South West England and Wales,

sleep hanging free by their feet. The remainder more commonly cling on with

thumbs and feet or squeeze themselves into crevices [5].

Which British Bats Use Buildings?

Common pipistrelle, soprano pipistrelle and brown long-eared bats are the species

encountered most frequently in buildings but other species that may be present

are Brandt’s, whiskered, serotine, Leisler’s and Natterer’s bats. In the South West of

England and Wales greater and lesser horseshoe bats may also be found. The older

a building is, the greater the likelihood of use by bats and the greater the diversity

of species that may be present. It is often in our older buildings that some of our

rarest bat species are found. It is also often these older buildings that are more

likely to require roof repairs. In these cases BRMs are often recommended as they

help prevent condensation build up in the roof void and aid preservation of

original materials.

Breathable Roofing Membranes

Breathable roofing membranes (BRM’s) have been used in buildings for many years

now and, more recently, in cold pitched roof constructions without traditional

eaves ventilation. The benefit of reduced heat loss and not having to incorporate

ventilators has seen their use grow. BRM’s typically comprise spun-bonded

polypropylene or polypropylene/polyethylene laminated either side of a micro-

porous film. In more recent times the variability of BRM characteristics has

increased with the number of layers found in membranes ranging from a single

layer too four plus. The main performance requirements for roofing membranes are

water tightness, energy conservation and durability[15]. They have a structure that

is sufficiently fine to prevent liquid water penetration, yet not too fine to prevent

the transfer of water vapour. The main advantage of the BRM’s is the reduction of

heat lost through the ceiling/loft space to the outside. In a conventional roof system

up to 25% of the heat is lost this way [16].

The major degradation factors considered at present by manufacturers are

temperature, solar radiation, water, and wind. These can also be compounded by

inadequate design, poor workmanship and lack of maintenance[15]. No tests are at

present carried out in relation to the use of a membrane by wildlife, including bats.

Ways in which BRM may affect bat roosts Through preliminary research it has become apparent, that at least some of these

membranes, in certain circumstances, can be detrimental to bats. This project will

consider the following effects;

Entanglement Threat

Where bats are known to use the membranes as a roost, damage can lead to the

materials posing an entanglement threat. Any bats that did manage to get onto the

upper surface of this type of membrane would be unable, or find it very difficult, to

get out; they may very well die as a result. The traditional hessian reinforced

bitumastic roofing (BS747) with a sand finish, however has not had any such

problems knowingly associated with it [14].

13

Material Surface

In order to roost bats must be able to gain a purchase on the material, they prefer a

surface on which they can get a good grip with their toes and thumb claws. Many of

the modern roofing felts and membranes have a smooth and slippery surface. These

are generally unsuitable for bats, especially those bats that are crevice dwellers and

choose to roost between the felt and roof covering [14]. Bats will also avoid dusty,

flaking surfaces. A recent study [17] showed that limited access to natural roosts in

Poland was not the main reason for roosting in buildings, and that one of the most

significant variables in determining bat occurrence in a building is the presence of

roof lining. This would suggest that the materials used within a roof system

occupied by bats could have a great effect upon the roost suitability.

Fig 1. Examples of bats that have died as a result of membrane entanglement. The thumb claw is

often seen as a point of entanglement.

BRM still

attached to

claws

BRM still

attached to

claws

13

Ways in which Bats may affect BRM’s

Evidence seen prior to this study beginning has shown that bat activity can cause

damage to the surfaces of BRM. As well as posing an entanglement threat, it is

assumed that such damage may result in the effectiveness of the membrane being

compromised. The level of damage caused by bat claws through usage as a roost

will be considered in this project. We will focus not only on friction caused through

bats dragging along the fabric, but the shape of the claws of species known to roost

in buildings and the effect of a hanging load.

Materials and Methods Little scientific work has been done previously on bat claw morphology or how bats

interact with breathable roofing membranes. This project aims to collect data via

modified methods from raptor talon morphology[18], published data on BRM

performance through BBA certificates and British standards and mechanical testing

of BRM samples in the laboratory using original techniques. The aim of collecting

claw morphology data is so that mimetic claws can be designed to allow accurate

analysis of membrane damage under bat usage conditions.

Fig 2. Evidence of the damage bat roosts can cause to Breathable Roofing membranes. These photos show different

levels of severity.

13

Claw Morphology

In order to take precise measurements of the thumb claw it is essential to have a

good lateral view of the thumb and claw for photographing.

This reduced the number from that of preserved skins studied, as many could not

be photographed in a clear enough manner. A total of 175 specimens were studied;

78 from the Vincent Wildlife Trust in Dorset and 97 from the Natural History

Museum in London. All specimens had general measurements taken from them and

were photographed for future work. Additional data (age, sex, location, year found)

was also collected where possible.

Out of 175 specimens 150 were photographed in such a way that they could be

analysed for claw morphology (see fig3.). Specimens that could not be photographed

adequately for precise measurement were used to assess the validity of claw

morphology trends inferred from measured specimens.

Specimens that were of sufficient quality had a variety of measurements taken.

Claw length and claw width(measured using methods from [19]), arc length (AL0 for

outer and ALi for inner), chord length (CLo for outer CLi for inner) and curvature

radii measurements were taken on macro photographs of the claws using AutoCAD

2011. Measurements were taken for both inner and outer claw edges in case one

later proved more informative than the other. In previous work[18, 20]the radius

and angle of claw curvature were subsequently used to calculate claw ‘‘size’’: the

arc length. However, in AutoCAD, arc length could be measure directly and thus

reducing error margins.

Arc length and chord length were then used to calculate a ‘hooked’ ratio (fig 4.)

which allowed comparison of claw shape between species, and also removed the

effect of body size.

Tearing and Cutting properties of Breathable Roofing Membranes

Samples of all the breathable roofing membranes (BRMs) commercially available in

the UK were obtained, along with samples of traditional bitumen roofing felt.

Where available data was collected on all of these membranes in relation to tear

Fig 3. Close up photos were taken of the thumb claw using a macro function. Each photo was

taken along-side a reference scale to allow use in AutoCAD 2011.

13

tests carried out for British Agrement certificates and the number of layers that

were used to create the membrane. This data is to be placed into a database along

with test results to be carried out in the laboratory. It is hoped this will allow

comparison of current and future products available on the market, with factors

that make BRMs more amenable for bat colonization.

PRELIMINARY RESULTS

From the data collected so far, it has been possible to run an ANOVA statistical test

on the following parameters; Claw length (CL), Claw width (CW), Outer claw

hooked ratio (OHR) and Inner claw hooked ratio (IHR). All of the above factors

showed a significance of p= <0.05 between species apart from IHR. Fig 5. Shows the

average data of each factor considered, CL and CW which showed extremely high

significance between species (p= 2E-32 and p= 3.4E-21 respectively) show obvious

variance between the species. Claw length has long been an indicator for species

identification in some bats and now this data would suggest there is a significant

difference between at least some species, if not all. OHR also showed significance

between species (p=0.0185) although when comparing this graph to that of IHR

which showed no significance there appears to be little difference. It could

therefore be that one species is significantly different, but until more data is

collected and more powerful analyses run it is not possible to say if this factor will

be considered when designing mimetic claws for materials testing.

DISCUSSION

The preliminary results found in this project are vital in helping to understand how

bats may interact with membranes. This data can also be used to see if the life

history of bats affects how they roost within buildings and if this will also play a

Outer Claw Arc

length ALo

Outer Claw Chord

length CLo

Inner Claw Arc

length ALi

Inner Claw Chord

length CLi

Fig 4. Example of how the claw ‘hookedness’ was measured from

photographs

Claw Hook Ratio =

ALo or ALi

CLo CLi

13

part in membrane interaction. Of course much more work is required to reach this

stage in the project. Initially more data will be collected using methods stated

above. This is to allow for accurate comparisons and more powerful statistical

analyses. The data collected will then be used to carry out testing in the laboratory.

Future tests will involve carrying out scissor and tear tests on BRM s, using

equipment within the laboratory and adapted BS testing methods.

The results from the claw morphology data will then also be used to create a

mimetic claw. This may be a general shape to cover all species or an individual claw

for those species that are found roosting in buildings. This claw will then be used to

carry out friction and wear and tear tests, to determine the mechanical properties

that make these membranes more or less amenable to bat colonization.

0

0.5

1

1.5

2

2.5

3

Pa Pau Bb Mb Rf Rh Nl Mm Mn Nn Pp Es Ppy

Average Claw Length

0

0.2

0.4

0.6

0.8

1

1.2


Average Claw Width

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6


Outer Claw Hooked Average

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6


Inner Claw Hooked Average

Fig 5. Average data graphs for the factors that underwent ANOVA testing. Data labels are abbreviated as follows;

Pa (Plecotus auritus), Pau (Plecotus austriacus), Bb (Barbastella barbastellus), Mb (Myotis brandtii), Rf (Rhinolophus

ferrumequinum), Rh (Rhinolophus hipposideros), Nl (Nylatus leisleri), Mm (Myotis mystacinus), Mn (Myotis natteri), Pp

(Pipistrellus pipistrellus), Es (Eptesicus serotinus), Ppy (Pipistrellus pygmaeus).

13

Key References

1. English Heritage, Bats in Traditional Buildings. 1st ed, ed. J. Ferneyhough. 2009: Pureprint Group.

2. Schofield, H.W. and A.J. Mitchell-Jones, The Bats of Britain and Ireland. 2nd ed. 2003: The Vincent wildlife trust.

3. Stubbs, A.E., THE WILDLIFE AND COUNTRYSIDE ACT 1981. Entomologist's Record and Journal of Variation, 1982. 94(3-4): p. 57-59.

4. Entwistle A, H.S., Hutson A, Racey P, Walsh S, Gibson S, Heburn I, Johnston J, Habitat management for bats, JNCC, Editor. 2001, Joint Nature Conservation Committee.

5. CCW, Bats in Roofs: A Guide for Building Professionals, ed. CCW. 2005: The Countryside Council for Wales. 12.

6. Chruszcz, B.J. and R.M.R. Barclay, Thermoregulatory ecology of a solitary bat, Myotis evotis, roosting in rock crevices. Functional Ecology, 2002. 16(1): p. 18-26.

7. Hutchinson, J.T. and M.J. Lacki, Selection of day roosts by red bats in mixed mesophytic forests. Journal of Wildlife Management, 2000. 64(1): p. 87-94.

8. Kerth, G., K. Weissmann, and B. Konig, Day roost selection in female Bechstein's bats (Myotis bechsteinii): a field experiment to determine the influence of roost temperature. Oecologia, 2001. 126(1): p. 1-9.

9. Lausen, C.L. and R.M.R. Barclay, Thermoregulation and roost selection by reproductive female big brown bats (Eptesicus fuscus) roosting in rock crevices. Journal of Zoology, 2003. 260: p. 235-244.

10. Willis, C.K.R. and R.M. Brigham, Defining torpor in free-ranging bats: experimental evaluation of external temperature-sensitive radiotransmitters and the concept of active temperature. Journal of Comparative Physiology B-Biochemical Systemic and Environmental Physiology, 2003. 173(5): p. 379-389.

11. Sedgeley, J.A., Quality of cavity microclimate as a factor influencing selection of maternity roosts by a tree-dwelling bat, Chalinolobus tuberculatus, in New Zealand. Journal of Applied Ecology, 2001. 38(2): p. 425-438.

12. Vonhof, M.J. and R.M.R. Barclay, Use of tree stumps as roosts by the western long-eared bat. Journal of Wildlife Management, 1997. 61(3): p. 674-684.

13. Lausen, C.L. and R.M.R. Barclay, Benefits of living in a building: big brown bats (Eptesicus fuscus) in rocks versus buildings. Journal of Mammalogy, 2006. 87(2): p. 362-370.

14. Morris, C. (2008) The 'Morris' Batslate. Volume, 11 15. Lounis, Z., et al., Towards standardization of service life prediction of roofing

membranes. Roofing Research and Standards Development: Fourth Volume, 1999. 1349: p. 3-18.

16. BBA (2004) Breathable roof tile underlays in cold roofs. Volume, 5 17. Mazurska, K. and I. Ruczynski, Bats select buildings in clearings in Bialowieza

Primeval Forest. Acta Chiropterologica, 2008. 10(2): p. 331-338. 18. Pike, A.V.L. and D.P. Maitland, Scaling of bird claws. Journal of Zoology, 2004.

262: p. 73-81. 19. Dietz, C., O. von Helversen, and D. Nill, Bats of Britain, Europe and Northwest

Africa. English edition ed. 2009, London: A&C Black Publishers Ltd. 20. Fowler, D.W., E.A. Freedman, and J.B. Scannella, Predatory Functional

Morphology in Raptors: Interdigital Variation in Talon Size Is Related to Prey Restraint and Immobilisation Technique. Plos One, 2009. 4(11).

13



The Carbon Life Cycle of Buildings: A Review of the Current UK Carbon

Emissions Reduction Strategy for Buildings.

H. J. Darby1*, A.A. Elmualim2, F. Kelly3

1Technologies for Sustainable Built Environments, University of Reading, UK

2School of Construction Management and Engineering, University of Reading, UK

3Peter Brett Associates LLP, Reading, UK

*Corresponding author: [email protected]

ABSTRACT

The UK government has set targets to reduce carbon emissions by 34% and 80% by

2020 and 2050 respectively. It is estimated that the building sector is responsible

for 52% of the UK emissions. These consist of operational (during use) and

embodied (during design, manufacture of materials and components, construction,

refurbishment, demolition, reuse and recycling). To date, the focus has been on

operational emissions, with the aim of reducing them to zero. However, the

importance of embodied emissions is now becoming apparent, as is the interaction

between the operational and embodied elements. It is argued that, in order to take

full advantage of potential overall emissions savings from buildings, a truly holistic

approach is required when analysing life cycle carbon emissions, rather than

focusing purely on the operational element. To move forward effectively on

embodied emissions, accepted methodologies, assessment boundaries, material data

sources and associated software tools are required, which are consistent, accessible,

reliable and objective.

Keywords:

Embodied carbon; life cycle assessment; carbon emission; building; operational

carbon

1. INTRODUCTION

The UK Climate Change Act came into force in November 2008 and set targets to

reduce carbon emissions by 34% below 1990 levels by 2020 and 80% by 2050 (DECC,

2009).

UK carbon emissions are shown in Figure 1, according to economic sectors (The

Carbon Trust, 2008)



13

Figure 1: UK Carbon Emissions by Sector (The Carbon Trust, 2008)

The building sector is responsible for 44% of the total. However, this figure is an

underestimate as it is derived from the energy consumed by buildings only while in

use, and does not take into account the energy consumed in the extraction or

manufacture of the materials and products required for construction work, the

process of transporting and assembling them, or in refurbishment and demolition.

These elements are counted in the industry and transport sectors (BIS, 2010).

Therefore, in reality, the carbon emissions from all activities associated with the

whole life cycle of buildings is estimated to be around 52% of the UK’s total (BIS,

2010). It is clear that, without drastic reductions in overall emissions from

buildings, it will not be possible to meet the UK reduction targets.

2. OPERATIONAL AND EMBODIED CARBON Carbon emissions from a building (or a buildings carbon footprint) can be divided

into operational (during use) and embodied (during design, manufacture of

materials and components, construction, refurbishment, demolition, reuse and

recycling). A typical carbon life cycle for a building is shown in Figure 2.

Figure 2: Building Carbon Life Cycle

The UK Government’s first step in achieving carbon emission reductions has,

understandably, been to tackle operational emissions. Over the lifetime of a

building this is generally the largest component and reduction measures the most

straightforward to implement.

Industry

Transport

Agriculture

Buildings

13

The October 2010 revision of Part L of Building Regulations (Conservation of fuel and power) contains increasingly stringent, graduated, operational carbon (OC) reduction requirements compared with the current 2006 regulations (ODPM, 2006). It will require new domestic buildings to be ‘zero carbon’ by 2016, new public buildings to be ‘zero carbon’ by 2018, and all other new buildings to be ‘zero carbon’ by 2019. However, ‘zero carbon’ in this context only refers to OC. Other, non-mandatory, systems for influencing the environmental performance of buildings in the UK include The Building Research Establishment Environmental Assessment Method (BREEAM) (www.breeam.org, 2009) and The Code for Sustainable Homes (CSH) (CLG, 2008). These award weighted credits in different categories of environmental impact, including operational energy and carbon emissions during building use, and materials used during construction. They effectively attach significantly greater importance to OC emissions than to embodied carbon (EC) emissions and the weighted credits allow the highest environmental rating to be achieved without any consideration of EC. Together with the lack of readily available and usable data on EC, this has meant that there has been little incentive to consider EC in building design. However, the situation is now changing and EC is rising up the building industry’s agenda. The IPCC Climate Change 2007 report (Levine et al., 2007) states “The embodied energy in building materials needs to be considered along with operating energy in order to reduce total life cycle energy use by buildings”. The Low Carbon Construction IGT: Emerging Findings report (BIS, 2010) states “...the IGT regards its scope as being necessarily concerned with emissions from the whole life cycle of the process of design and construction, including...embodied energy; and also with emissions resulting from the use of the building to the extent that the industry can feasibly influence them.”

3. RELATIONSHIP BETWEEN OPERATIONAL AND EMBODIED CARBON

A review of the literature has identified various data and case studies, which have

allowed the magnitude of the EC and OC components to be estimated, in order to

assess the potential for overall carbon savings (Battle, 2010; BioRegional

Development Group, 2009; CIBSE, 2004; Connaughton, 2007; Cox, 2010; Eaton &

Amato 1998; Jones, 2007; Kelly, 2007; Lane, 2007; Lazarus, 2009; Middleton, 2007;

Philips Smith, 2008; SCI, 2003; Sturgis & Roberts, 2010; Symons & Symons 2009;

Vukotic, 2008). A summary of these data and studies is presented in Figure 3 for

different building sectors, for new buildings constructed in accordance with the

2006 edition of Part L of the Building Regulations.

http://www.breeam.org/

13

Figure 3: 2006 ratio of embodied to operational carbon based on a review of the

literature

The range of reported EC is shown as a percentage of the OC. As might be

expected, buildings with high energy usage during their operational life, such as

residential, offices, education and retail have low EC in relation to OC, and

warehouses with low energy usage have relatively high EC.

The range of proportions of EC as a percentage of OC are:

Residential: 3% to 30%

Offices: 11% to 54%

Education: 2% to 14%

Retail: 25% (one case study only)

Sports and Leisure: 8% to 25%

Warehouses 79% to 108%

Unspecified buildings 14% to 58%

There is a wide range within and between each building group and the reasons for

this will be considered in Section 4. Nevertheless, if the future planned reductions

in OC are taken into account, the percentages of embodied relative to operational

will inevitably increase. Figure 4 shows a possible 2019 scenario where operational

is reduced to 30% of the 2006 standard.

This shows generally that EC will be close to, or greater than OC. The 30% value reflects the ‘worst case’ scenario for the current thinking on the definition of ‘zero carbon’, which is still under debate.

0

20

40

60

80

100

120

em opem op

em opem op

em opem op

em op

Residential - Offices - Education - Retail - Sports and

Leisure

- Warehouses - General

Buildings

(undefined)

Embodied carbon (min) Embodied carbon range Operational carbon

13

Figure 4: Possible 2019 ratio of embodied to operational carbon

(assumes ‘zero (operational) carbon’ with 30% allowable solutions)

The current definition for homes (DCLG, 2008) is a 70% reduction in carbon emissions against 2006 standards through a combination of energy efficiency, on-site low and zero carbon (LZC) energy supply and/or connections to low carbon heat networks (‘carbon compliance’), with the remaining emissions to be addressed through a system of ‘allowable solutions’. Government is yet to confirm what the range of allowable solutions are, but they are likely to include credits for the following options: any energy efficient appliances or advanced forms of building control system; low carbon or renewable heat (or cooling) exported from the development to existing properties that were previously heated (or cooled) by fossil fuels; S106 Planning Obligations paid by the developer towards local LZC energy infrastructure; retrofitting works undertaken by the developer to transform the energy efficiency of existing buildings in the vicinity of the development; any investment by the developer in LZC energy infrastructure; any other measures that Government might in future announce as being eligible. This appears to be Government acknowledgement that, in most cases, it will be virtually impossible to be 100% ‘zero carbon' (operational) on site, due to the technological limitations on electricity and heat generation for individual buildings in urban situations. This means that a building can be defined as ‘zero carbon’ by reducing its operational emissions to 30% of the 2006 standard and is, perhaps, the more likely option to be adopted in many cases. It is reasonable to assume that the ’allowable solutions’ quoted above would involve some cost increase. In most cases, because they frequently involve reducing the weight of materials used, low EC solutions are more likely to involve a cost reduction, which would make them a more economically efficient option.

It should be noted that Figure 4 does not take into account likely increases in EC as

a result of measures employed to reduce OC, for example, by increasing insulation

thickness, or providing increased building mass to use as thermal storage. A

0

100

200

300

400

em opem op

em opem op

em opem op

em op

Residential - Offices Education - Retail - Sports and

Leisure

- Warehouses - General

Buildings

Embodied Carbon (min) Embodied carbon range Operational carbon

13

hypothetical scenario leading to true ‘zero (operational) carbon’ could be as

illustrated in Figure 5. The early reductions in OC are achieved without large

increases in EC but further reductions become increasingly difficult to achieve. A

possible undesirable outcome from focusing on OC alone, without considering the

interaction with EC, is an increase in the overall carbon above the minimum

achievable.

Conversely, using materials with low EC in place of materials with high EC does not

necessarily reduce emissions on a life cycle basis, as it will depend on the effect of

materials choice on the operational requirements for heating and cooling etc. over

the lifetime of the building and whether the materials can be reused or recycled at

the end of their life.

Figure 5: Possible effect on overall carbon with a

drive to zero operational carbon

(Hypothetical illustration)

Figure 6 shows the EC, OC and total whole life carbon profile for an office building

based on case study data (Sturgis and Roberts, 2010). Increases in EC during the

building life represent refurbishment works. The OC is based on the predicted

performance of the case study building.

2006 2010 2012 2014 2016 2019

Embodied Operational

13

Figure 6: Whole life carbon for an office building

(data from Sturgis and Roberts, 2010)

Figure 7 shows the hypothetical total whole life carbon profiles for two different

types of construction for the same building, constructed in the year 2010 and with a

life expectancy of 60 years. The first type is a heavyweight building with relatively

high EC but with relatively low OC and the second a lightweight building with

lower EC but higher OC. This hypothetical figure is used to illustrate that at some

point in the future the profiles would cross, in this case at around the year 2035.

Although after year 2035 the heavyweight building has lower total emissions, prior

to 2035, in this respect, the lightweight building performs better.

Figure 7: Whole life carbon – comparison of

heavyweight and lightweight construction

(Hypothetical illustration)

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60

Building Life (years)

% o

f W

ho

le L

ife C

arb

on

Whole life carbon Operational carbon Embodied carbon

0

20

40

60

80

100

120

2010 2020 2030 2040 2050 2060 2070

Year

% o

f H

ea

vy

we

igh

t B

uild

ing

Wh

ole

Lif

e C

arb

on

Whole life carbon

heavyweight buiding

Whole life carbon

lightweight building

13

This brings into focus the timeframe in which carbon reductions need to be made,

and raises the question about whether carbon savings today are more valuable than

predicted savings in the future. In terms of meeting the 2020 reduction targets the

lightweight solution is preferable, but apparently not for the longer term.

However, as much of the OC is a result of electricity use, the effect of future

decarbonisation of electricity supply could have a profound effect on the latter part

of the profiles. Additionally, it is thought that more efficient M&E equipment of

future refits may also alter this outcome.

4. MEASUREMENT OF EMBODIED CARBON The process of determining embodied carbon for a building appears, at first sight,

fairly straightforward. It simply involves calculating the quantities of all the

materials, energy and wastes involved with the activities, multiplying by the

appropriate carbon emission factor for each and adding together to find the total.

In reality it is a far more complex process with many uncertainties and unknowns.

One of the major problems is the lack of a standardised and universally adopted

methodology of life cycle analysis for buildings. Work under the European

Standards Mandate M350 ‘Sustainability of Construction Works’ (BSI, 2010) seeks to

remedy this by developing a harmonised approach to the measurement of

embodied and operational environmental impacts of construction products and

whole buildings, across the entire life cycle. At this stage, it is not clear when this

will become available. In the meantime, PAS 2050 (BSI, 2008) is available, which

builds on the life cycle analysis frameworks given in the BS EN 14040 (2006) suite of

standards and the Greenhouse Gas (GHG) Protocol (WRI and WBCSD, 2004)

developed by the World Resources Institute and the World Business Council for

Sustainable Development in 2004. PAS 2050 focuses exclusively on GHGs produced

during the life of a product and services. However there is huge scope for

variability in the data, life cycle boundaries selected, and assumptions made

(TRADA, 2009a).

It is crucial in any carbon footprint exercise to establish the footprint boundaries

and to be consistent when making comparisons.

The boundaries for a true whole life cycle carbon assessment of buildings should

encompass:

all building phases including the end of life scenarios (cradle to grave) as shown in Figure 2

all building components, including substructure, superstructure, cladding, finishes, services and fit-out

consistent life expectancy for each of the components

consistent energy mix used for electricity production

consistent unit of emission (Carbon; CO2; all GHGs or CO2equivalent; Global warming potential)

materials data source which is consistent, accessible, reliable and objective

13

Table 1 lists the variability which exists in currently available databases for the

emissions from materials alone, for three commonly used construction materials.

The scope for variability is considerable.

Material embodied carbon (kgCO2/t)

Hammon

d, G.,

Jones, C.,

2008

Environme

nt Agency,

2009

Edinburgh

Centre for

Carbon

Manageme

nt

Ashby,

M. F.,

2009

IStructE

, 1999

Industr

y

quoted

figures

steel 1770* 1770* 2300***+ 2200 to

2800* 2030* 762***+

concret

e

80 to

209*

78 to

129* 250***+

130 to

150*

119 to

208* 115***+

timber 460* 460* -1000***+ 400 to

490* 1644*

-1590 to

3920**+

+

Life cycle phase: *cradle to gate; **cradle to grave; ***unknown

Source: + Smith, 2010; ++ TRADA, 2009b

Table 1: CO2 emissions from various data sources

For example, each of the materials comes in different forms, each with their own

EC. Concrete contains a number of constituents (cement, cement replacements,

aggregate, water, sand, admixtures) in an infinite variation of ratios, which affect

the embodied carbon. Timber has its own particular issue of carbon sequestration

(locked up carbon absorbed during a tree’s growth) and whether this should be

subtracted from its life cycle carbon. The quantity of recycled material used in the

production of steel or as concrete aggregates can have a significant effect on the

production emissions of the new material.

There are a plethora of software tools and online ‘carbon calculators’ available

purporting to provide whole life assessments but in many cases it is unclear exactly

where the assessment boundaries have been drawn and which data sources have

been used.

Full details of the case studies reviewed in Section 3 were not available, although it

is clear that different boundaries were employed. Therefore, no firm conclusions

can be drawn from these studies alone. However, as might be expected, the later

13

studies, which included all building components and life cycle phases, give the

higher EC proportions.

5. CONCLUDING REMARKS The timeframe for delivery of carbon savings, the increasing proportion of the EC

element and its interaction with OC means that, in order to take full advantage of

potential overall carbon reductions from buildings, a truly holistic approach is

required when analysing life cycle carbon emissions. This approach may also result

in economic benefits.

To move forward effectively on the EC agenda, accepted methodologies, assessment

boundaries, material data sources and associated software tools must be developed,

which are consistent, accessible, reliable and objective. Current work has identified

twenty four different EC software tools, which are currently available, and seven in

the development stage. Validation of theses tools within the context of the built

environment will be reviewed in future publications.

REFERENCES:

Ashby, M. F. (2009) "Materials and the environment", Butterworth - Heinemann,

Oxford

Battle G. (2010) “Embodied Carbon – Time to make it count”, Deloitte, London.

BioRegional Development Group (2009) "BedZED seven years on", BioRegional

Development Group, Surrey.

British Standards Institution (BSI) (2008) ”Publicly Available Specification PAS

2050:2008: Specification for the assessment of the life cycle greenhouse gas

emissions of goods and services”, BSI, London.

Chartered Institution of Building Services Engineers (CIBSE) (2004) "Energy

Efficiency in Buildings, CIBSE Guide F", CIBSE, London.

Communities and Local Government (CLG) (2008) “The Code for Sustainable Homes:

setting the standard in sustainability for new homes”, CLG, London.

Connaughton, J. (2007 October 3) "Underestimate embodied energy at your peril",

Building.

Cox S. (2010) Presentation at UK-GBC “Embodied Carbon Event” 5 May 2020,

London.

Department for Business, Innovation and Skills (BIS) (2010) “Low Carbon

Construction IGT: Emerging Findings”, BIS, London.

Department for Communities and Local Government (DCLG) (2008) "Definition of

Zero Carbon Homes and Non-domestic Buildings: Consultation", DCLG, London.

Department of Energy and Climate Change (DECC) (2009) “The UK Low Carbon

Transition Plan - National strategy for climate and energy”, DECC, UK.

Eaton K. J. & Amato A. (1998) 2A comparative environmental life cycle assessment of

modern office buildings" SCI P-182, The Steel Construction Institute, Ascot, Berks.

Environment Agency (2009) “Carbon Calculator, version 3.1.1”.

Hammond, G., Jones, C.(2008) “Inventory of Carbon & Energy (ICE) Version 1.6a”, University of Bath.

13

IStructE.(1999) “Building for a sustainable future: Construction without depletion”, SETO, London.

Jones, W. (2007 November 20) "Pines Calyx - setting the sustainable standard",

Building.

Kelly, F. (2007 April) "Steel tops sustainability study", New Steel Construction 15/4

p14-15.

Lane, T. (2007 November 11) "Our Dark Materials", Building p 44-47.

Lazarus, N. (2009) "BedZED: Toolkit Part I", BioRegional Development Group, Surrey.

Levine, M., D. Ürge-Vorsatz, K. Blok, L. Geng, D. Harvey, S. Lang, G. Levermore, A.

Mongameli Mehlwana, S. Mirasgedis, A. Novikova,J. Rilling, H. Yoshino (2007)

“Residential and commercial buildings. In Climate Change 2007: Mitigation.

Contribution of Working Group III to the Fourth Assessment Report of the

Intergovernmental Panel on Climate Change [B. Metz, O.R. Davidson, P.R. Bosch, R.

Dave, L.A. Meyer (eds)]”, Cambridge University Press, Cambridge.

Middleton, K. (2007 October 4) "New software released to measure embodied

energy", Building.

Office of the Deputy Prime Minister (ODPM) (2006) “The Building Regulations 2000,

Conservation of fuel and power, Approved Documents L1A and L2A, Conservation

of fuel and power in new dwellings (2006 edition)”, NBS, London.

Philips Smith, B. (2008 March 18) "Whole-life Carbon Footprinting", The Structural

Engineer 86/6 p15-16.

Smith S (2010) Presentation at “In Touch With Timber” 18 May 2010, London.

Steel Construction Institute (2003) "Steel Designers Manual, 6th Edition", Blackwell,

Oxford.

Sturgis S. & Roberts G. (2010) “Redefining zero”, RICS, London.

Symons, K. and Symons, D. (2009 May 5) "Embodied energy and carbon - what

structural engineers need to know", The Structural Engineer 87/9 p19-23.

The Carbon Trust (2008) “Management Guide 038 - Low Carbon Refurbishment of

Buildings - A guide to achieving carbon savings from refurbishment of non-domestic

buildings”, The Carbon Trust, London.

TRADA Technology Limited (TTL) (2009a) “Construction briefings: PAS 2050: A

Summary of the Standard and its Background”, TTL, High Wycombe, UK.

TRADA Technology Limited (TTL) (2009b) “Construction Briefings: Timber carbon

footprints”, TTL, High Wycombe, UK.

Vukotic, L. (2008) "An assessment of building structural elements lifecycle embodied

energy and CO2 emissions”, Mphil Thesis, University of Cambridge, Cambridge.

World Resources Institute (WRI) and World Business Council for Sustainable

Development (WBCSD) (2004), “The Greenhouse Gas Protocol, A Corporate

Accounting and Reporting Standard, revised edition”, WRI&WBCSD, USA.

www.breeam.org “BRE Environmental Assessment Method (BREEAM)” (consulted November 2009).

www.bsigroup.com/Standards-and-Publications/Committee-Members/Construction-

committee-members-area/M350-Standards/?id=158921 (consulted May 2010).

http://www.breeam.org/

http://www.bsigroup.com/Standards-and-Publications/Committee-Members/Construction-committee-members-area/M350-Standards/?id=158921

http://www.bsigroup.com/Standards-and-Publications/Committee-Members/Construction-committee-members-area/M350-Standards/?id=158921

13



Introduction to Energy Use in Food Retail Spaces

E. K. Mottram1*, H. Awbi1, J. Barlow2, B. Gregson3, J. Broadbent3

1Technologies for Sustainable Built Environments, University of Reading, UK 2Department of Meteorology, University of Reading, UK

3Johnson Construction, Delph, Oldham, UK


ABSTRACT

Energy use in food retail spaces has become increasingly relevant to

supermarket chains in recent years as energy prices have risen, customers

have become increasingly environmentally aware, and government

regulations have provided ever stricter requirements for the performance of

non-domestic buildings. It is therefore useful for stores to be aware of where

their energy requirements come from and how they can be reduced. This

paper details the findings of a preliminary examination of energy use in two

Cooperative stores in the UK and uses a literature review to put these in

context. Potential measures that could be used to reduce supermarket

energy consumption in the areas of refrigeration and entrance design are

examined and areas requiring further research are identified. It is concluded

that research into combinations of refrigeration based energy saving

methods, detailed energy use patterns, wind lobby performance and design

and the development of passive entrance design would be beneficial in

reducing energy demands of food retail spaces.

Keywords:

Supermarket, Energy Use Patterns, Refrigeration, Entrances, Monitoring

1. INTRODUCTION

As of 2001, the services sector accounted for 14% of UK energy consumption,

of which retail made up 18%, and in 2000 Retail accounted for one third of

all electricity consumption in the service sector (DTI, 2001). Retailers

therefore have a significant role to play in the reduction of the UK’s energy

demand. The food retail sector is particularly energy intensive as much of its

produce requires refrigeration, significant amounts of heat are lost through

frequently (or constantly) opened entrances, and there is often food



13

preparation on site. Light level standards in store require between 750 and

1000 lux at working height in the sales area (CIBSE, 1994). This is

significantly higher than standard requirements for offices, and is a result of

the use of light to highlight products and increase customer purchases.

It is thought that the current low energy efficiency of systems in a large

proportion of supermarkets leads to great scope for energy reductions. This

paper attempts to provide information on how energy use is divided

between different applications within supermarkets at present and identify

areas in which significant savings might be made. It then sets out the plan

for future research and details which areas will be focused on.

2. HOW IS ENERGY USED IN STORES?

2.1 Literature Review Energy use in supermarkets varies widely depending on the size, design,

location and activities of a store. A recent survey (Baker, 2004) found that the

average energy use of a supermarket was 1378kWh/m2 per year. Results

varied between 1163kWh/m2 and 1528kWh/m2 per year depending on the

company among the responding retailers.

Supermarkets use energy for various applications within their stores.

Refrigeration makes up over 50% of electricity consumption in any store

selling significant quantities of chilled or frozen goods (Energy Star, 2007).

Freezers and chillers need running constantly both in the sales and storage

areas. They can be expected to use less energy at night as they will be

opened less frequently and in the case of open front-of-house chillers, blinds

can be pulled down to keep warm air out (Baxter, 2002). Lighting is usually

the next biggest user for the reasons described earlier (personal

communication, Stevenson, 2010).

As demonstrated by the data from Maidment and Cairns, it is difficult to

predict the next largest energy use factor. This seems to be more store

dependent, but heating and ventilation are usually significant, since they are

often working against the refrigeration plant to maintain comfortable

temperatures in store. In integrated refrigeration systems heat is being

produced at the back of chillers and freezers. The second law of

thermodynamics suggests that the heat produced will be greater than the

heat removed so that the net action of an integrated refrigeration unit will

be to warm the space it occupies. This heating can often cause the

temperature in stores to rise to uncomfortable levels and require

considerable air conditioning to correct it. Conversely if the refrigeration

system is remote, i.e. the heat is rejected outside the store area, then stores

can often become uncomfortably cold. This is a particular problem if chiller

13

units have no doors and do not efficiently contain the cold air produced. The

recent ‘fashion’ for chillers to have shelving down to very low levels in units

has worsened this problem, as the cool air is harder to contain (Cairns, 2010).

Many stores also use a reasonable amount of energy in ovens (see figure 2),

either for an in store bakery (in larger stores) or just for heating foods for the

hot counter. In stores with ovens energy use for this purpose can be

substantial, especially if they are not run efficiently. Smaller uses of energy

include generation of hot water, tills, food and drink preparation equipment

for staff and other equipment used by staff running off wall sockets (e.g.

floor polishers).

Table 1. Heat loads under design conditions for a supermarket (Maidment, et

al, 2001)

Heat load at design (kW)

% of total load

Fabric -230.35 40.96

Air Infiltration -324.39 57.68

Solar 17.14 -3.05

Hot water -10.20 1.81

Lights 89.87 -15.98

Occupancy 85.16 -15.14

Heat Absorption by Cabinets

-189.6 33.71

Total -562.37 100

Maidment et al (2001) collected data on energy applications for a large

Sainsbury’s store at Penge in London. They found the distribution shown in

Figure 1. Compressors and condensers, and cabinets and cold stores fall into

the category of refrigeration energy use. Maidment also details the

contribution of various positive and negative factors to heating

requirements. The findings are shown in Table 1 above. The values for these

factors are likely to vary with store size and design, but the order of

magnitude is likely to be similar for most stores.

Two studies have been identified which attempt to model energy usage

within stores, with varying degrees of success. Chung et al (2006) attempted

to use benchmarking and multiple regression analysis to identify

correlations between annual energy use and other factors in commercial

buildings. These included building age, internal floor area, number of

customers annually, equipment type, temperature settings and occupants’

behaviour. They then applied these methods to a set of supermarkets. While

the results show some limited correlation, this does not seem strong enough

13

to base any reliable predictions on. Datta et al (1997) attempted to use neural

networks to identify relationships between external factors and energy

usage in a supermarket, with a view to using it to predict half-hourly energy

consumption. It was proven that these results were able to predict reality

with much greater accuracy than an equivalent regression analysis.

Relationships between day, time, internal and external humidity and

temperature and energy use were explored and it was found that the most

significant factor was time of day, followed by internal temperature and

external humidity.

Figure 1: Electricity usage within a store. (Maidment, et al, 2001)

2.2 Case Studies Figure 2 below shows distributed electricity use for a Co-Op store at Archway

in North London. Data was collected over a number of months using

domestic electricity sub-metering and processed by an independent

contractor. The lighting demand was not recorded, nor was electricity used

by the goods lift, air curtain or ‘small power’. While this limits the data’s

usefulness a number of conclusions can still be drawn.

At 52% refrigeration demand makes up the bulk of electricity usage in this

store, as suggested above, though the introduction of lighting consumption

data might change this figure slightly. It was noted in the data that at least

one air conditioning unit was being left on continuously by mistake. If this

were corrected the distribution might be closer to the average.

Energy use varies throughout the day, week and year. This is a result of

various factors but includes opening hours, weather, peaks and troughs in

customer numbers, timer settings for machinery operation etc.

32%

34%

23%

6%

5%

Lighting

Compressorsand Condensors

Cabinets andCold Stores

HVAC

Misc

13

Figure 2: Electricity usage distribution in Archway Co-Op store - Lighting

omitted (pers. comm. N. Cairns)

Figure 3 below shows the pattern of energy usage by day of the week

averaged over 84 days between July and October 2009 for a Co-Op store in

Hornsea, on the Yorkshire coast. This clearly backs up the finding in Datta’s

study that time of day is the most significant explanatory factor in energy

usage. It can be seen that in this store the baseline electricity usage is around

14 kWh per half hour. This is largely made up of the refrigeration demand

which must continue overnight as well as during working hours. This will be

lower than the daytime refrigeration demand as at night blinds are used to

keep heat out of the units. This store also has reduced opening hours on

Sundays as demonstrated by the narrower peak. It can be seen that there are

some peaks and troughs common to all days. These are likely to correspond

to machinery switching on and off with timers. This will be store specific

and there is not enough information to confidently determine their origin.

52%

12%

4%

2%

30% Refrigeration

Air Conditioning

Hot Water

Bakery Fans

Ovens

0

5

10

15

20

25

30

35

40

00

:00

01

:00

02

:00

03

:00

04

:00

05

:00

06

:00

07

:00

08

:00

09

:00

10

:00

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:00

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:00

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:00

14

:00

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:00

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:00

17

:00

18

:00

19

:00

20

:00

21

:00

22

:00

23

:00

Hal

f h

ou

rly

en

erg

y u

se (

kWh

)

Time

Sunday

Monday

Tuesday

Wednesday

Thursday

Friday

Saturday

13

Figure 3: Average daily energy use pattern by day of the week at Hornsea

Co-Op (data from pers. comm. G. Stevenson).

3. SCOPE FOR ENERGY REDUCTIONS

3.1 Refrigeration James (2009) has compiled a list of potential energy saving measures

applicable to refrigeration in supermarkets. The largest potential saving

comes from putting doors on chillers. It is claimed that this measure could

save up to 50% of refrigeration energy costs, though this is thought to be an

optimistic estimate based on a best case scenario. There are a number of

reasons why UK supermarkets have not, in large part, implemented this

measure, but one outweighs most of the others. It is perceived that having a

barrier between the customer and the product will drastically reduce

impulse buying and potentially lose supermarkets custom among people

who find opening doors inconvenient. Unless all supermarkets are required

by government regulation to install doors on their chillers it is unlikely that

it will happen to a great extent for many years. Several modern

‘environmentally friendly’ stores have started trials of the economic effect of

doors on chillers but none have yet rolled the measure out company wide.

The fear is that customers will find opening doors to get chilled goods

inconvenient enough that they may choose to go to a competitor for their

food instead. Other European countries have been using doors on fridges as

standard for a number of years.

Other related measures identified by James (2009) are strip curtains and

night blinds/covers. These could lead to reductions of 30% and 20% of

refrigeration energy use respectively. Supermarkets tend to avoid the use of

strip curtains in display cases in the UK as they are perceived as unsightly

and tatty. They are used in back-of-house cold storage to reduce air escape

when doors are opened, but are often at least partially removed by staff

members who find them awkward. Night blinds are becoming increasingly

common in British supermarkets and have noticeably reduced night time

energy consumption when used properly.

Optimising operation of refrigeration has large potential for savings through

measures including suction and discharge pressure optimisation (i.e. the

smaller the difference, the more efficient), use of electronically commutated

(EC) motors and fans in evaporators (2-8%), condensers (8%), and compressors

(15%). Another option is replacing conventional refrigeration lighting with

13

LEDs to reduce heat emissions and energy use (5-10%), though this is

currently rather expensive to retrofit.

A number of recent ‘eco-supermarkets’ built by big retailers including Tesco

and Sainsbury’s are running their refrigeration as part of a trigeneration

system on site, i.e. providing electricity, heating and cooling from the same

plant. James (2009) quotes a potential saving of 20% using this method.

Some supermarkets are also increasingly using carbon dioxide as an

alternative refrigerant in an attempt to reduce the environmental impact of

refrigeration. While this approach reduces the direct global warming

potential of emissions from refrigeration, these systems currently require

more energy to run, and cost more to install (Kruse, 2005), but it is thought

that the significantly lower impact of the leakage of CO2 will cause the

figure for total equivalent warming impact (TEWI) to be lower than for more

traditional systems. It currently seems likely that CO2 refrigeration will

eventually become the norm, so any energy saving measures will need to be

compatible with these systems.

Heat recovery from refrigeration is an appealing idea, but in practice there

are barriers to the use of this heat which have prevented its widespread

adoption to date. If a refrigeration system is designed to produce specific

amounts of heating as well as cooling it becomes much harder to optimise

the efficiency of the system and an inefficient way to generate heat (Pers.

Comm. Bainbridge, 2010). A solution being used by some refrigeration

specialists is known as a free heat pack. This effectively uses the rejected

heat from the refrigeration to preheat the hot water system. This removes

the need for load predictions and improves overall efficiency.

The above measures cannot always be used simultaneously, so for the best

arrangement more work is required to determine the best combination.

3.2 Entrances The nature of retail spaces means that the entrance of a store is open for a

large proportion of the time. As a result a large amount of heat can be lost or

gained through them, through both wind pressure and buoyancy effects.

Maidment (2001) found that 57.7% of the total heating load was attributable

to air infiltration, which would be largely through entrances. If it were

possible to reduce the wind pressure and buoyancy effects by minimising

the amount of air exchange between the outside and inside of the store,

then the heating demand could be significantly reduced.

The airflow through entrances depends on various internal and external

factors. Internal factors include whether draughts exist because multiple

13

entrances are in use, the type of system in use to reduce air infiltration and

the temperature being maintained. External factors include wind speed and

direction, temperature and humidity, orientation and arrangement of

nearby structures. Tahbaz (2009) has produced design graphs for estimating

the wind speed in urban areas below 10 metres. While useful for estimating

average wind speed, this method does not predict gustiness or air circulation

patterns which are important when modelling air infiltration through

doorways. Georgakis and Santamouris (2004) look in more detail at local

variations in wind speed, direction and temperature within an urban

canyon. This is most likely to be relevant to centrally located stores rather

than large out of town examples.

Most modernised stores make use of one or both of two possible methods to

reduce air infiltration. The first, used mostly in smaller stores is installation

of an air curtain. This is a device that blows a sheet of air over an entrance,

either vertically or horizontally in an attempt to redirect air flows and

minimise infiltration. This air can be warmed, cooled or ambient. Energy use

will vary, but in general more heat energy is saved than electricity is used to

power them. Research has been done by, among others, Valkeapää and

Anttonen (2004) on air curtain performance and design improvements. It

was found the air curtain can substantially reduce temperature variations

near doorways and heat loss, but that air velocities near doorways are largely

unchanged by the introduction of air curtains.

Entrance Lobbies (often known as draught lobbies) are structures put up at

the entrances to large stores (both supermarkets and other retailers) that

reduce wind pressure induced flow and buoyancy flow infiltration by

introducing a second set of doors, usually perpendicular to the main set of

doors and thus requiring customers (and wind) to go round a corner to enter

the store. It also creates a buffer space which could reduce buoyancy induced

leakage. These lobbies are often used in conjunction with air curtains to

further reduce heat loss. Little research is currently available on the design

and performance of wind lobbies in the supermarket setting. They can cost a

significant sum to install and require electricity to run, so if one is to

evaluate their cost-effectiveness, information needs to be gathered on how

they work, how well they work, and how much energy they consume.

Another potential option which is not currently in significant use in stores is

a system of passive baffles outside the entrance which could be designed to

redirect air away from the doorway while leaving easy access for customers.

It is hoped that if such a system could be developed it might prove

significantly cheaper to construct and run than the wind lobbies currently in

use by large stores.

13

When designing entrances and how to reduce infiltration, supermarkets

have to consider several factors. Small stores tend not to have wind lobbies

as these take up a large floor area which could otherwise be valuable retail

space (Stevenson, 2010). They are also less likely to own the area

immediately outside the entrance and could risk taking up the whole

pavement with such a structure. It is also important to remember when

designing an entrance that customers need to be able to access the store

while manoeuvring heavy shopping trolleys. Thus in the passive system the

baffles must not create sharp corners to be negotiated.

3.3 Energy monitoring

The author believes that monitoring energy use, and if at all possible

dividing it into application, provides great opportunities for reducing

inefficiencies. It should then become possible to identify where systems are

not being used as intended, where equipment is being left running

overnight and where current usage patterns could be improved. Staff

members can then be taught how to improve their store’s performance and

see evidence of the difference they have made. It could also provide evidence

of the efficacy of energy reduction measures that could help justify their use

in other stores. A basic version of this measure is being used on the Co-Op

stores mentioned earlier, but it is hoped that a more detailed case study will

result in larger reductions in energy use, provide potentially valuable data on

performance of new technology and a tested methodology for energy

reductions through monitoring. The effect of combinations of measures

could also more easily be investigated.

3.4 Other approaches

While this paper focuses on refrigeration, entrances and monitoring, there

are other areas for improvement. Increasing use of natural lighting, through

skylights where feasible and light sensors to regulate electrical lighting can

generate significant savings (Leslie, 2003). Using energy efficient

replacements during refits has delivered good reductions in energy use (pers.

comm. N. Cairns). A further way to reduce energy use in store is to modify

occupant behaviour by training and informing staff of how to operate their

store in the most efficient way (Cairns, 2010).

4. FUTURE RESEARCH

The author’s future research is expected to include detailed monitoring of

case studies in one or more Co-Op stores, with the anticipated outcomes

described above. The intention is to obtain and analyse detailed records of

energy use distribution over a substantial period of time and then to explore

13

how further reduction opportunities can be identified and evaluated through

use of this data.

It is hoped that various combinations of refrigeration measure will be

evaluated, and this could make use of the case studies above.

It is also anticipated that development work will be done on passive

entrance strategies. In order to evaluate potential benefits data will need to

be collected on current performance of wind lobbies to enable comparisons

to be drawn.

5. CONCLUSIONS

Energy use within food retail spaces is not uniform between all stores. It

varies between retailers and within retailers. Not all stores are the same or

conduct the same activities and when comparing store performances it is

important to remember this. The location, orientation, size, fabric, opening

hours and many other factors will have an influence over energy use.

The most significant users of energy in supermarkets are refrigeration,

lighting and space heating/cooling. The exact proportions of these vary from

store to store and over time. Refrigeration currently has the greatest

potential for energy reductions in the UK as more than 50% of energy is used

for this application in stores. Much work has already been done on how

these reductions might be realised, but further work may be beneficial to

identify effective combinations of measures.

A notable way to reduce space heating and cooling loads would be to

minimise the level of air infiltration through store entrances. Such measures

have already been taken in many stores but there is still room for

improvements and further research into this area could be fruitful.

The development of energy use monitoring through sub-metering is another

method by which energy reductions could be made.

REFERENCES

Bainbridge, D. (2010), A1 Refrigeration, meeting and personal

communications.

Baker, N. (2004), How Green is Your Supermarket? A Guide for Best Practice,

Green Lib

13

Dems Environment Team Papers, available at:

http://www.greenlibdems.org.uk/resources/sites/217.160.173.25-

3f0016a052c515.23380913/Environment%20Team%20Papers/Norman+Baker%

27s+Report+on+Supermarkets.pdf . accessed 04/06/10

Baxter, V. D. (2002), Advances in Supermarket Refrigeration Systems,

(available at http://www.arb.ca.gov/cc/commref/adv_supmkt_ref_syst.pdf )

accessed 04/06/10.

Cairns, N. (2010), Cooperative Group regional energy manager for the South-

East, Meeting and personal communications.

Chung, W., Hui, Y. V., Miu Lam, Y. (2006), Benchmarking the energy

efficiency of commercial buildings, Appl. Energy, vol. 83, no. 1, pp. 1-14.

CIBSE (1994), Code for interior Lighting 1994, CIBSE, p. 73.

Datta, D., Tassou, S. A., Marriot, D. (1997), Application of Neural Networks

for the Prediction of the Energy Consumption in a Supermarket, Proc. CLIMA

2000 Conf., p. 98.

DTI, (2001), Energy Consumption in the United Kingdom, Dept of Trade and

Industry, available at: http://www.bis.gov.uk/files/file11250.pdf accessed

04/06/10.

Energy Star, (2007), Supermarkets: An Overview of Energy Use and Energy

Efficiency Opportunities, available at

http://www.energystar.gov/ia/business/challenge/learn_more/Supermarket.pd

f accessed 04/06/10.

Georgakis, C., Santamouris, M. (2004), On the Air Flow in Urban Canyons for

Ventilation Purposes, Int. J. Vent., vol. 3, no. 1, pp. 53-65.

James, S. (2009), Potential Supermarket Energy Efficiency Options, available

at http://www.grimsby.ac.uk/documents/defra/retl-supermarketefficoptns.pdf

accessed 04/06/10.

Kruse, H. (2005), Commercial Refrigeration – on the Way to Sustainability,

IIF/IIR, Commercial Refrigeration, Vicenza.

Leslie, R. P. (2003), Capturing the daylight dividend in buildings: why and

how? Build. Environ. vol. 38, no. 2, pp. 381-385.

Maidment, G. G., Zhao, X., Riffat, S. B. (2001), Combined cooling and heating

using a gas engine in a supermarket, Appl. Energy, vol. 68, no. 4, pp. 321-335.

http://www.greenlibdems.org.uk/resources/sites/217.160.173.25-3f0016a052c515.23380913/Environment%20Team%20Papers/Norman+Baker%27s+Report+on+Supermarkets.pdf



http://www.arb.ca.gov/cc/commref/adv_supmkt_ref_syst.pdf

http://www.bis.gov.uk/files/file11250.pdf

http://www.energystar.gov/ia/business/challenge/learn_more/Supermarket.pdf

http://www.energystar.gov/ia/business/challenge/learn_more/Supermarket.pdf

http://www.grimsby.ac.uk/documents/defra/retl-supermarketefficoptns.pdf

13

Stevenson, G. (2010), Cooperative Group regional energy manager for the

North, Meeting and personal communications.

Tahbaz, M. (2009), Estimation of the Wind Speed in Urban Areas – Height

less than 10 Metres, Int. J. Vent., vol. 8, no. 1, pp. 75-84.

Valkeapää, A., Anttonen, H. (2004), Draught Caused by Large Doorways in

Industrial Premises, Int. J. Vent., vol. 3, no. 1, pp. 41-51.

13



Raising Energy Awareness in Refurbished Non-Domestic Buildings: Challenges

and Opportunities

M.M. Aghahossein1*, A.A. Elmualim2, M.J. Williams3 and A.D. Kluth4

1 Technologies for Sustainable Built Environments, University of Reading, UK 2 School of Construction Management and Engineering, University of Reading, UK

3 School of Psychology and Clinical Language Science, University of Reading, UK 4 Halcrow Group Ltd, Sustainability Group, London, UK


Abstract

The UK government is committed to 80% reduction in carbon emissions by 2050

compared with 1990 levels. As the number of existing buildings today is estimated

to account for about 60% of the total buildings in 2050, refurbishment of existing

buildings has a vital role to play in meeting the UK government’s target for

reduction in carbon emissions. It is therefore crucial to develop strategies to

improve the energy performance of the existing building stock by employing

innovative sustainable tools and technologies. However, without leadership

commitment and the engagement of end users, many features of such innovative

sustainable tools and technologies may be ineffective, and thus might not

contribute to carbon emission reductions.

This paper describes the core challenges of, and opportunities provided by, the

application of innovative tools, techniques and technologies to increase energy

awareness and improve occupant engagement in order to maintain the sustainable

performance of refurbished buildings.

Keywords: non-domestic buildings, sustainability, refurbishment, post occupancy

evaluation and carbon reduction.

1. Introduction

The UK has a target to cut national carbon emissions by 80% by 2050 compared with

1990 levels. About 18% of carbon emissions in the UK are generated from the

energy used in non-domestic buildings (UK Green Building Council, n.d.). As the

number of existing buildings today is estimated to account for about 60% of the

total buildings in 2050 (Delay et al, 2009), sustainable building refurbishment

represents the best opportunity to reduce carbon emissions and must be at the

heart of efforts to meet the government’s target.



13

Halcrow Group Ltd is refurbishing a leased 1930s, 5-storey office building in

Hammersmith, London. This building will replace the current Halcrow

headquarters building adjacent to the site. It will be ready in the second half of

2010 to be occupied, initially, by about 450 people who will move over from

Halcrow’s current offices in Hammersmith (Vineyard House (VH) and Shortlands).

Halcrow wishes to investigate the tools, techniques and technologies currently

available to reduce their energy consumption in their new HQ while increasing

their employee satisfaction and well-being. Considering that the capital budget for

this project is tight and, moreover, making any changes to the fabric of the building

is restricted, Halcrow considers it important to study how they might encourage

effective interaction with the building by the occupants, so as to maximise the

performance improvement opportunities available.

1.1 Background

It is possible to considerably reduce energy consumption by changing occupants’

attitudes and behaviour (Office of Energy Efficiency, 2001).

There are many technologies, such as renewables, water harvesting and grey water

recycling; already in existence that can contribute to the reduction of the energy

consumption and CO2 emissions in buildings. There are also many tools available,

such as double-glazed windows and efficient lighting with sensors, which can

improve the productivity and well-being of the end users while maximising the

energy performance of buildings. However, there are a number of case studies, such

as that of Wessex Water headquarters, which clearly show that, without user

engagement, none of these tools and technologies may be fully effective.

Wessex Water HQ in Bath was designed by Bennett Associates Architects in 2000.

This 10,000 m2 open plan office building has high levels of natural ventilation

(Figure 1). Rainwater recycling, solar shading and solar panels are some of the key

elements of this green building. Although this building was awarded an “Excellent”

BREEAM rating and has been acknowledged as one of the greenest office buildings

in Europe (Wessex Water, 2010), its performance suffered in the beginning because

of the way employees worked (Jones, 2008). To solve this problem, as well as

installing meters to each part of the building, a training programme was conducted

on how the building works and how the staff should interact with it (Jones, 2008).

13

Figure 10- Wessex Water HQ

From this case study, therefore, it seems that the focus should be on both

behaviour-change and the employment of innovative sustainable technologies,

when aiming to improve and maintain the energy performance of buildings.

There are two separate issues to be addressed concerning changing occupants’

behaviour and creating a culture of energy-saving amongst them. One is raising

occupants’ energy awareness so that they may understand why and how to save

energy. The other involves encouraging occupants to become engaged in energy

efficiency initiatives (Thorne and Fisher, 2005).

1.1.1 Raising Occupant Energy Awareness

UK industry is losing about £7 million every day, 21% of the UK’s total energy costs,

as a result of poor energy efficiency (Carbon Trust, 2005). By comparison it is

estimated that changing occupants’ behaviour could reduce the energy costs of

companies by £2.5 billion and cut carbon emissions by 22 million tonnes (Carbon

Trust, n.d., cited in Opus Energy, 2010). Therefore, it is important to raise

occupants’ energy awareness and educate them about how such simple actions as

turning off lights and computers, can have a direct effect on energy consumption.

A Management Guide published by the Carbon Trust (2005) about creating an

awareness campaign, identifies some of the tools and techniques that could be used

to educate occupants and communicate energy data to them. These tools and

techniques include:

Team meetings and presentations, which are good face-to-face methods of distributing energy data when effectively deployed;

Online or printed booklets and newsletters to explain why and how energy consumption needs to be reduced within an organisation;

Displays and posters to communicate about particular issues with building users or suggest the need for immediate action, which are effective when they are placed in appropriate locations and are highly visible (Figure 2)

13

Stickers on pieces of equipment to give appropriate direction; Internal competitions to motivate occupants.

Halcrow as an organisation is keen in exploiting the opportunities offered by the

guide. Two posters shown in Figure 2 were positioned next to the lifts during

Halcrow’s sustainable travel week in May 2010 to encourage employees to use the

stairs.

Figure 11: Halcrow Vineyard House Office

According to the survey of emerging best practices at 30 large global organisations,

many initiatives, such as creating posters, have been tried by most of the

organisations to raise employee energy awareness (Baier and Tommaszewski, 2009).

However, the effectiveness of these initiatives has rarely been evaluated.

Electronic signs, energy awareness days (or weeks) and screen savers have proven

effective in raising energy awareness and creating interest about improved energy

performance (Office of Energy Efficiency, 2001).

In 2006, Logica UK initiated an internal “Stamp Down Our Carbon Footprint”

campaign to raise their employees’ energy awareness, and reduce their energy

consumption and environmental impact. As part of this campaign, an intranet was

created to provide advice on alternative ways to travel and information about the

building’s monthly energy consumption (Logica, n.d.). In October 2008, webinar

presentations about climate change were given to the employees by external

experts (Logica, n.d.). All these actions, combined with other initiatives such as

video conferencing, recycling, employing free cooling technology in a data centre

and producing more efficient IT infrastructure, led to a significant carbon footprint

reduction of 15% within 2 years (Logica, n.d.). A 40% reduction in business air travel,

28% reduction in road travel, 9% reduction in paper usage and 26% reduction in

water consumption were achieved by Logica UK within two years after the

campaign started (Logica, n.d.). Paul Wiltshire (2009), the Logica Facilities

13

Operations Manager, notes that future initiatives will include introducing hot-

desking and encouraging home working and evaluation of their effectiveness.

Another example is the successful employee energy awareness programme which

was employed by the Canadian Forces Base, Gagetown, (Office of Energy Efficiency,

2001). A range of tools, such as posters, a calendar with energy information and

dates for energy awareness activities; and holding an energy awareness week, were

used in this programme.

Large organisations usually appoint “Environmental Champions” to help raise

awareness and spread the word and inspire. Chloe Lewis (2010), the environmental

consultant at VH, notes that since environmental champions were appointed on

each floor, there has certainly been more awareness. However, no adequate

measurements of energy consumptions or attitude change are available to support

the contention that this technique has demonstrable benefits.

1.1.2 Occupant Engagement

According to Baier and Tommaszewski (2009) many initiatives such as recycling,

bicycle racks, carpooling, Earth Day activities and posters have been tried by many

organisations, but, again, very few of these initiatives have been assessed for their

effectiveness.

DEFRA’s London headquarters (Nobel House) have provided bicycle parking space

for 10% of the occupants, and also have provided video conferencing facilities to

reduce the need for air travel (Otto, n.d.).

A significant success factor in energy saving in an office building is senior

management commitment (Thorne and Fisher, 2005). The personal support and

commitment of a specific senior manager can play a vital role in generating and

maintaining employee engagement. Bell (2010), the Regional Director of the

Halcrow Glasgow office believes that senior management leadership and

commitment is very important for energy efficiency initiatives’ success. Bell (2010),

who is actively involved in the Glasgow office plan for travel behavioural change,

says: “If the guy at the top does it, it normalises the behaviour.”

For energy efficiency initiatives to be effective in an organisation, employee

engagement is crucial (Office of Energy Efficiency, 2004). Organising special events

or “theme” days and weeks gives the employee the chance to learn more and get

engaged in the program. For example, Halcrow has been running a sustainable

travel week called “Spring into Action” since 2007 (Figure 3). This event includes

free cycle training, cycle maps and guides and a free “Dr Bike” bike repair and

advice service.

13

Figure 3: Halcrow Spring into Action Week

Offering personal benefits to building occupants can also motivate them to get

more involved in energy saving initiatives. For example, Halcrow offers interest free

loans for the purchase of season tickets and bicycles. In addition, Halcrow Glasgow

office has employed a new parking strategy where commuters pay a fee for spaces

which subsidises bus tokens sold to staff who opt to commute by public transport.

For each initiative being tried in an organisation, progress reports and provision of

feedback can encourage the staff to get more involved (Carbon Trust, 2005).

It is argued that there are many technologies and techniques available to be applied

into refurbished buildings to improve their sustainability. However, for these

technologies to be effective, occupant commitment is required.

2. Project Aims & Objectives

Aim: to investigate how innovative technologies for sustainability can be applied to

refurbished buildings and how behavioural change can be encouraged in order to

achieve the most sustainable performance.

Objectives are:

Carrying out a pre-occupancy evaluation regarding energy consumption, CO2 emission and occupants’ satisfaction;

Developing flexible and adaptable tools and techniques to improve energy consumption in refurbished buildings;

Developing initiatives to raise employee energy awareness and encourage their engagement;

Monitoring and evaluating the performance of the new tools and technologies applied to the refurbished building in terms of energy saving, and also creating a ‘sustainable community’

Monitoring and measuring the effectiveness of the initiatives taken, in increasing employee energy awareness and reducing energy consumption

13

Managing and maintaining the sustainable performance of the building; Identifying new/ improved user behaviours; Providing best practice guidelines and a training program.

3. Challenges and Opportunities

Particular challenges and opportunities within this research include that:

There are some staff who think sustainability is not relevant to their daily job;

Not all people believe that individual input can make a difference; Changing people’s behaviour is a difficult task; Available energy efficiency tools, such as home working, hot-desking, bike-

pooling, energy dashboards and recycling, need to be monitored and their effectiveness evaluated;

The effectiveness of available occupant energy awareness initiatives, such as posters, theme weeks and presentations, needs to be regularly monitored and evaluated;

The sustainable performance of buildings can be maintained by motivating and engaging the occupants;

An occupant/employee energy awareness handbook can be provided.

4. Methodology

This research project requires the use of both qualitative and quantitative methods

(Figure 4). At the pre-occupancy stage, all available energy and water data will be

collected and reviewed.

Action Research methodology will be used in this research to evaluate the

combined effects of environmental changes and employee engagement and

education taking place over time. Therefore, from the beginning, all groups of

stakeholders who will, either directly or indirectly, be affected by the results of this

research will be identified and kept regularly informed via different channels of

communication. Two presentations have already been given to groups of employees

about the aims of the research.

To set achievable targets for reducing energy consumptions, all restrictions and

opportunities within the building will be assessed. In addition, factors such as type

of facility and equipment, size of the building, number of staff, hours of occupancy

and occupant expectations will be considered before the targets are set.

An employee survey is already being conducted to collect data regarding employee

satisfaction, needs and expectations. This benchmark survey, which comprises two

parts, allows employees to confidentially express how they feel about their work

environment. The first part of this survey includes questions concerning

demographic factors such as age, sex, place of work and employment status. Also,

in this part, employees are asked to specify their modes of transportation to work

13

and their willingness to work at home. The aim of these questions is to allow the

assessment of the potential amount of transport CO2 emissions that might be cut

by working at home. In the second part of the survey, employees are asked to

indicate their levels of satisfaction with their workplace physical environment, use

of interior space, indoor facilities and current policies. In addition, in the latter part,

the employees are asked to state whether they are aware of Halcrow’s sustainability

target and whether they feel personally responsible for contributing to Halcrow’s

sustainability objectives. Their responses should indicate employees’ motivation

and awareness levels.

In the next step, various innovative tools, techniques and technologies will be

investigated; a selection of these will then be applied to the refurbished building

with the aim of improving its energy performance. Financial resources will be

considered at this stage. Desirable behaviours will be identified and various ways of

motivating occupants, such as use of incentives and internal competitions, will be

considered.

Figure 4: The Research Program Framework

At the post-occupancy stage, the effectiveness of the applied tools, techniques and

technologies will be monitored and measured. This will be done by collecting and

analysing energy and water data on a regular basis. Employee surveys will be

conducted to assess any improvement in employee satisfaction. Behavioural data

will also be collected. For example, environmental champions, selected from

enthusiastic individuals on each floor, can be assigned explicit roles and

responsibilities. These champions will monitor employee behaviour and identify

changes in behaviour as part of their role.

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13

A feedback system will be employed whereby employees’ views and opinions will

be monitored throughout the research. An employee energy awareness handbook

will be designed for the use of current and new employees and, finally, best

practice guidelines will be provided to be used in future developments.

5. Conclusion

Sustainable building refurbishment plays a vital role in reducing carbon emissions

and, therefore, must be at the heart of efforts to meet the UK’s ongoing and

increasingly challenging carbon reduction targets.

There are many sustainable innovative technologies and tools available to be used

in refurbished buildings to save energy. However, these technologies will only be

effective when the occupants are aware of the importance of reducing energy

consumption and are engaged in maintaining the building’s energy performance.

Only a few of the energy awareness initiatives employed so far have been

monitored and evaluated in terms of their effectiveness.

An employee energy awareness handbook and best practice guidelines are needed

for use in programmes for refurbishing buildings sustainably.

6. References

Baier, P. Tomaszewski, B., 2009, Employee Engagement for Sustainability, Groom Energy Solutions Bell, D. [email protected]. Regional Travel Award, Scotland. 14 May 2010.

Carbon Trust, 2005, Management Guide: Creating an awareness campaign, Queen’s

Printer and controller of HMSO

Carbon Trust, n.d., cited in Opus Energy, 2010, Rising employee awareness, [online],

Available from: http://electricityadvice.opusenergy.com/module/page-254/employee-

awareness.cfm (Accessed 19/05/2010)

Delay, T., Farmer, S., Jennings, T., 2009, Building the future today - Executive summary -

Transforming the economic and carbon performance of the buildings we work in, Carbon Trust

Jones, W., 2008, Bennetts Associates Architects' Wessex Water HQ reviewe, [online],

Available from: www.bdonline.co.uk/news/bennetts-associates-architects-wessex-

water-hq-reviewed/3106259.article (Accessed 05/05/2010)

Lewis, C. [email protected], Environmental champions. 19 May 2010

Logica, n.d., Stamp down on carbon (Logica case study), Transformation in a Low Carbon

Economy

http://electricityadvice.opusenergy.com/module/page-254/employee-awareness.cfm

http://electricityadvice.opusenergy.com/module/page-254/employee-awareness.cfm

http://www.bdonline.co.uk/news/bennetts-associates-architects-wessex-water-hq-reviewed/3106259.article

http://www.bdonline.co.uk/news/bennetts-associates-architects-wessex-water-hq-reviewed/3106259.article


13

Office of Energy Efficiency, 2001, EMPLOYEE AWARENESS AND THE FEDERAL

BUILDINGS INITIATIVE, Natural Resources Canada, [online], Available from:

http://oee.nrcan.gc.ca/communities-government/buildings/federal/pdfs/employee-

awareness.pdf (Accessed 15/05/2010)

Office of Energy Efficiency, 2004, Saving Money Through Energy Efficiency, Natural

Resources Canada, [online], Available from:

www.oee.nrcan.gc.ca/Publications/commercial/pdf/eii-awareness.pdf (Accessed

15/05/2010)

Otto, B., n.d., Sustainable office design, Morgan Lovell, [online], Available from:

http://www.morganlovell.co.uk/useful-info/white-papers/sustainable-office-design-

unlocking-performance-productivity/ (Accessed 16/11/2009)

Thorne, A., Fisher, J., 2005, Raising staff awareness of energy saving, Fundamental series,

Pinede Publishing

UK Green Building Council, n.d., Existing Non Domestic Buildings, [online], Available

From: http://www.ukgbc.org/site/info-centre/display-category?id=24 (Accessed

29/04/2010)

Wessex Water, Operations Centre, [online], Available from:

http://www.wessexwater.co.uk/about/threecol.aspx?id=108 (Accessed 06/05/2010)

Wiltshire, P., 2009, Carbon Plus Workshop seminar, Logica and Ecosearch, London

.

http://oee.nrcan.gc.ca/communities-government/buildings/federal/pdfs/employee-awareness.pdf

http://oee.nrcan.gc.ca/communities-government/buildings/federal/pdfs/employee-awareness.pdf

http://www.oee.nrcan.gc.ca/Publications/commercial/pdf/eii-awareness.pdf

http://www.morganlovell.co.uk/useful-info/white-papers/sustainable-office-design-unlocking-performance-productivity/

http://www.morganlovell.co.uk/useful-info/white-papers/sustainable-office-design-unlocking-performance-productivity/

http://www.ukgbc.org/site/info-centre/display-category?id=24

13

Abstracts of Poster Papers: TSBE EngD Conference, TSBE Centre, University of


Abstracts for Posters

Study of Parameters Affecting Performance of Solar Photovoltaic (PV)

Systems of Various Designs Operating in the Field

P. Burgess1*, M. Vahdati2, S. Philips3

1 TSBE Centre, University of Reading, Reading, UK 2 School of Construction Management and Engineering, University of

Reading, UK 3 SSE, Thatcham, UK


ABSTRACT

The purpose of the EngD project is to develop a detailed understanding of

the performance of a wide range of PV systems of a variety of technologies

and the factors affecting this (including locational factors and environmental

factors). Information in this area is increasingly important as planning

requirements and the recently introduced microgeneration feed in tariff are

expected to drive growth in the UK PV sector. Detailed data will be gathered

from around six sites (PV system performance - both DC from modules & AC

from inverter, Environmental data - module temperature, ambient

temperature, irradiance, windspeed). This data will be used to anchor

existing datasets to build up a database of PV system performance across the

UK. This database will be used to create a tool for representing and

interrogating the data in useful ways, possibly as a map. Ultimately this will

improve the prediction of yield from PV systems and provide a sound

starting point for offering remote monitoring services.

Key Words:

Solar photovoltaic, PV systems, PV database.



13

The TSBE Centre would like to thank the EPSRC and all their sponsoring

companies for their invaluable help and assistance in putting together the

papers for this Conference. Special thanks are due to our two Key Speakers –

Professor Jeremy Watson from ARUP and Mr Gavin Walker from Peter Brett

Associates.

We are also indebted to our colleagues at the Walker Institute for funding

the prize monies awarded today for the Best Research Engineer Conference

Paper and the Best Research Engineer Presentation.

The 1st Annual TSBE EngD Conference - reading.ac.uk...In November 2009, Jeremy ... Processes and NPD...

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