Internship Final Report Design and Analysis of Commercial ... · Design and Analysis of Commercial...

Internship Final Report

Design and Analysis of Commercial

Photovoltaic Systems

Prepared By Lee Joo Shen

Jan 2014

Design and Analysis of Commercial Photovoltaic Systems and Components

1

I. Abstract

Renewable energy industry has been booming since 8 years ago and has been growing

exponentially since 2010 since the production costs of PV systems have greatly reduced

due to technological advancements. Balance Utility Solutions (BUS) was established in

2011 to cope with the growing market for embedded generation. BUS has completed

multiple energy generation projects over Australia and Asia over 2013.

BUS is a member of the Balance Services Group, alongside with our client Barclay

Engineering (BE), the client for the 9.04kWp grid-connected PV install.

The initial aim of the project was to acquire the related system approvals, design and

procurement and implement the system before the end of the contract. This would

serve not only as a investment to our client, but also a facility to train BUS personnel for

rack assembly and also serve as a test facility for future developments. Along the way 2

minor projects were also undertaken and included as minor projects.

It was later discovered that alongside the 4kW of PV modules that BE had also bought

battery banks, a standalone inverter its associated balance of system which could then

be implemented and designed to operate like dedicated UPS systems that are available

on the market. Fundamental operational specification also documented as part of the

future plans for the project.

Minor project 1 was an involvement in other document preparation including a tender

document for a 150kWp PV system for a wastewater plant. This involved planning and

documenting the project delivery; acquiring quotes for components and understanding

and complying with the scope that is required by the client. PV systems above 100kW are

uncommon in WA, and require protection relays to be integrated and approved by

Western Power.

Minor project 2 was the small test of the Sun Power PV modules and their degradation

when modules are operational for two years and stored for an additional year. Results

were then used to locate the module that has suffered the most degradation and omit it

from the design. Results are discussed in section 12.


2

II. Disclaimer

I declare that this thesis is my own account of my research and contains as its main content work, which has not previously been submitted for a degree at any tertiary education institution.

.................................... (Your name)

In the case of a re-submitted thesis the wording of the declaration should be as follows:

I declare that this thesis is my own account of my research. .................................... (Your name)


3

III. Acknowledgements

This project was in courtesy of Balance Utility Solutions (BUS), for which I would like to thank for

giving the chance to taste the engineering world. It would not have been possible, without their

guidance and experience in their industry. First and foremost, I would like to express my deepest

appreciation to Mr Mike Laughton-Smith (CEO), who is a well-established electrical engineer himself,

for welcoming me to the industry, showing great leadership, offering me help with assembling my first

work desk and keeping the workplace sanity with his uncanny humour.

It was an honour to have worked with my industry supervisor, Dr. James Darbyshire, who I would like

to thank for selflessly sharing his knowledge and technical knowledge, which is amongst the best of

the industry.

I would also like to extend my sincere gratitude to Mr. Alessio Ricchiardi, who always took time off his

busy schedule to guide me throughout my placement with BUS with enthusiasm.

Special thanks must also be given to my university supervisors Dr. Gareth Lee who answered every

query I had for Murdoch’s internship program and Dr. Sujeewa Hettiwatte, who answered every query

in such a timely manner.

I am also greatly indebted to all my university colleagues, in particularly Ms. Tanvi Gupta, and Mr.

Daniel Allison. For their immense moral support and invaluable assistance, which pointed me in the

right path and complete my work.

Last but not least, I would like to thank my parents for their unconditional love, care and support

towards me when it was most important.


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IV. Glossary

The following acronyms are used throughout this document

Acronym Meaning

AC Alternating Current Active conductor Conductor not directly connected to earth BE Barclay Engineering BUS Balance Utility Solutions BOS Balance of System, wiring, CB etc. to complete the

electrical system

CAG Competing application group CB Circuit breaker, means for disconnection when over

current occurs CEC Clean Energy Council DC Direct Current ETAC Electricity transfer access contract Grid connected PV system that is connected to the electrical grid

through an inverter and does not have a storage system

IP Ratings Ingress Protection IWC Interconnection works contract Inverter Power converter, it is also referred to as the inverter LGC Large generation certificate MEN Multiple Earth to Neutral MPPT Maximum power point tracking PCE Power converter equipment, referring to the inverter POA Point of approval PV Photo Voltaic PV cell Electronic device to convert solar energy to electrical

energy

PV module A combination of PV cells connected in series to increase the voltage output

PV string A combination of PV modules connected in series PV system System comprising PV array, inverter and associated

equipment

Racking The framework of the PV modules REBS Renewable energy buyback scheme REC Renewable Energy Certificates SPD Device to protect an electrical system from the danger

of high voltage spikes

SLD Single Line Drawing STC Small technology certificates SWIS South-Western Interconnected grid UPS Uninterruptable power supply WP Western Power


5

Table of contents

I. ABSTRACT ................................................................................................................ 1

II. DISCLAIMER ............................................................................................................. 2

III. ACKNOWLEDGEMENTS ............................................................................................ 3

IV. GLOSSARY ................................................................................................................ 4

1 INTRODUCTION ....................................................................................................... 9

1.1 PROJECT OBJECTIVE ....................................................................................................... 11

1.2 LAYOUT OF PV ............................................................................................................. 12

1.3 COMPANY HISTORY ....................................................................................................... 13

2 SIMULATION TOOLS ............................................................................................... 14

2.1 HOMER ....................................................................................................................... 14

2.2 TRIMBLE SKETCH UP ...................................................................................................... 14

3 PRELIMINARY AUTHORIZATION .............................................................................. 15

3.1 INTRODUCTION ............................................................................................................. 15

3.2 THE SOUTH WEST INTERCONNECTED SYSTEM (SWIS) ........................................................ 15

3.3 ADDITIONAL PROCESS OF PV INSTALLATIONS IN THE SWIS NETWORK .................................... 16

3.3.1 Synergy Application ........................................................................................... 17

3.3.2 Western Power Application (Less or equal to 30kVA) ....................................... 18

3.3.3 Renewable Energy Certificates (RECs) ............................................................... 18

3.4 SUMMARY ................................................................................................................... 19

4 FEASIBILITY STUDIES .............................................................................................. 20

4.1 INTRODUCTION ............................................................................................................. 20

4.1 RESOURCE ANALYSIS ..................................................................................................... 21

4.2 FINANCIAL ANALYSIS ..................................................................................................... 22

4.3 CAPITAL COSTS ............................................................................................................. 25

4.4 SUMMARY ................................................................................................................... 26

5 DESIGN .................................................................................................................. 27

5.1 INTRODUCTION ............................................................................................................. 27

5.2 IMPORTANT PROPERTIES OF PV SYSTEMS ......................................................................... 28

5.2.1 Ingress protection .............................................................................................. 28

5.2.2 Maximum Power Point Tracking (MPPT) ........................................................... 29

5.2.3 BI – Directional Meter ........................................................................................ 29

5.3 CHOOSING AN INVERTER ................................................................................................ 30

5.4 DESIGN 1 (1 INVERTER) .................................................................................................. 31

5.4.1 Issues and Solutions to design error .................................................................. 32

5.5 DESIGN 2 (3 INVERTER) .................................................................................................. 33

5.6 CABLE CALCULATIONS: ................................................................................................... 34

5.7 CIRCUIT BREAKER/ENCLOSURE ........................................................................................ 39

5.8 CABLE ROUTING AND CABLE TYPES ................................................................................... 40

5.9 LIGHTNING PROTECTION SYSTEMS (LPS) .......................................................................... 41

5.9.1 External Lightning Protection ............................................................................ 41


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5.9.2 Internal Lightning Protection ............................................................................. 43

5.10 LIGHTNING PROTECTION RISK ASSESSMENT .................................................................... 45

5.11 EARTHING ................................................................................................................. 46

5.12 CONNECTORS ............................................................................................................. 48

5.13 SUMMARY ................................................................................................................. 49

6 PROCUREMENT ...................................................................................................... 50

6.1 INTRODUCTION ............................................................................................................. 50

6.2 ITEMS TO BE PROCURED ................................................................................................ 50

6.3 SUMMARY ................................................................................................................... 51

7 IMPLEMENTATION ................................................................................................. 52

7.1 INTRODUCTION ............................................................................................................. 52

7.2 FENCING OPTIONS ........................................................................................................ 53

7.3 GROUND-MOUNTED RACKING SYSTEM: ............................................................................ 55

7.4 SYSTEM SECURITY ......................................................................................................... 57

7.4.1 Recommendation for Security of the System ..................................................... 57

7.5 SUMMARY ................................................................................................................... 58

8 COMMISSIONING ................................................................................................... 59

8.1 INTRODUCTION ............................................................................................................. 59

8.2 QUALITY ASSURANCE TESTING ........................................................................................ 60

8.3 COMMISSIONING TEST INSTRUCTIONS AND TEST SHEETS ..................................................... 61

8.4 SUMMARY ................................................................................................................... 61

9 FUTURE PLANS AND RECOMMENDATIONS ............................................................. 62

9.1 INTRODUCTION ............................................................................................................. 62

9.2 SUNNY ISLAND 5048 ..................................................................................................... 63

9.3 UPS SYSTEMS .............................................................................................................. 64

9.3.1 Operation of UPS systems .................................................................................. 65

9.4 SUMMARY ................................................................................................................... 66

10 MINOR PROJECT 1 – TECHNICAL DESIGN OF 150KW SYSTEM ................................... 67

10.1 DEMONSTRATED UNDERSTANDING OF THE SCOPE OF WORK: .............................................. 68

10.2 PROCESS OF DELIVERY OF GOODS AND SERVICES ............................................................... 69

10.3 APPROVALS FOR THE SYSTEM ........................................................................................ 71

11 MINOR PROJECT 2 – TESTING OF SUN POWER MODULES ........................................ 85

11.1 INTRODUCTION........................................................................................................... 85

11.2 OBJECTIVE OF TESTING ................................................................................................ 85

11.3 BACKGROUND ............................................................................................................ 86

11.4 METHOD ................................................................................................................... 88

11.4.1 Data Processing ............................................................................................... 88

11.5 RESULTS .................................................................................................................... 89

11.6 SUMMARY ................................................................................................................. 92

12 OVERALL CONCLUSION ........................................................................................... 93

13 LEARNING EXPERIENCES ......................................................................................... 93


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14 ANNOTATED BIBLIOGRAPHY .................................................................................. 95

15 REFERENCE ............................................................................................................ 96

16 APPENDICES........................................................................................................... 99

16.1 A1: SYNERGY BI-DIRECTIONAL METERING GENERATION ..................................................... 99

16.2 A2 : WESTERN POWER APPLICATION ............................................................................. 99

16.3 A3: SYNERGY APPROVAL.............................................................................................. 99

16.4 A4: WESTERN POWER APPROVAL ................................................................................. 99

16.5 A5: SMA SB2500-TL DATA SHEET ............................................................................... 99

16.6 A6: STP 5000TL-20 DATA SHEET ................................................................................. 99

16.7 A7: FRONIUS IG15 DATA SHEET .................................................................................... 99

16.8 A8: KYOCERA KD315GX-LPB DATASHEET ..................................................................... 99

16.9 A9: SUN POWER SPR-200-BLK DATASHEET ................................................................... 99

16.10 A10: SINGLE LINE DIAGRAM OF 9.04KW SYSTEM ......................................................... 99

16.11 A11: BOS COMPONENT LIST ...................................................................................... 99

16.12 A12: APPROVED LOCATIONS FOR PV ........................................................................... 99

16.13 A13: SPR-200-BLK TEST RESULTS ............................................................................. 99

16.14 A14: BE COMMISSIONING INSTRUCTIONS AND TEST SHEETS ........................................... 99

16.15 A15: FENCING OPTION A .......................................................................................... 99

16.16 A16: FENCING OPTION B .......................................................................................... 99

16.17 A17: FENCING OPTION C .......................................................................................... 99

16.18 A18: EMAIL CORRESPONDENCE WITH FRONTIER RACK ................................................... 99

16.19 A19: EMAIL CORRESPONDENCE WITH FRONTIER RACK ................................................... 99

16.20 A20: LOW LEVEL GANTT CHART FOR MINOR PROJECT .................................................... 99

16.21 A21: LIGHTNING RISK ASSESSMENT ............................................................................ 99

16.22 A22: CABLE LOSS CALCULATIONS ( ................................................................ 99

16.23 A23: CABLE LOSS CALCULATIONS ( ) ................................................................... 99

16.24 A24: SUNNY ISLAND 5048 DATASHEET ........................................................................ 99

16.25 A25: PROJECT PLAN (24/01/2014) ........................................................................... 99


8

LIST OF FIGURES

FIGURE 1: AERIAL VIEW OF SITE ................................................................................................................... 10 FIGURE 2: LAYOUT OF PV AT BARCLAY ENGINEERING ....................................................................................... 12 FIGURE 3: BI-DIRECTIONAL METER INSTALLED ................................................................................................ 17 FIGURE 4: SOLAR RESOURCE (HTTPS://EOSWEB.LARC.NASA.GOV/SSE/) .............................................................. 21 FIGURE 5: OVERVIEW OF SYSTEM ................................................................................................................. 37 FIGURE 6: SLD AND BREAKER SPECIFICATIONS ................................................................................................ 38 FIGURE 7: MAIN DISTRIBUTION BOARD ......................................................................................................... 40 FIGURE 8: PREVENTION OF WIRING LOOPS IN CIRCUITS [26] ............................................................................ 42 FIGURE 9: EARTHING CONDUCTOR SELECTION [29] ......................................................................................... 47 FIGURE 10: SHADING FROM FENCE .............................................................................................................. 53 FIGURE 11: DESIRED FENCING OPTION ......................................................................................................... 54 FIGURE 12: BEFORE PREPARATION ............................................................................................................... 56 FIGURE 13: THICKNESS OF CONCRETE .......................................................................................................... 56 FIGURE 14: FLOW OF APPLICATION FOR GENERATOR UP TO 150KVA .................................................................. 72 FIGURE 16: CONCRETE FOOTINGS ................................................................................................................ 74 FIGURE 17: SITE LAYOUT ............................................................................................................................ 75 FIGURE 18: SWITCH ROOM LAYOUT .............................................................................................................. 76

List of Tables:

TABLE 1: ENERGY ANALYSIS (HTTPS://EOSWEB.LARC.NASA.GOV/SSE/) ............................................................... 22 TABLE 2: OFF PEAK AND PEAK SAVINGS ......................................................................................................... 23 TABLE 3: ENERGY CONSUMPTION ................................................................................................................ 23 TABLE 4: OFF PEAK AND ON PEAK SAVINGS ................................................................................................... 24 TABLE 5: INGRESS PROTECTION OF INVERTERS ................................................................................................ 28 TABLE 6: INVERTER COMBINATIONS .............................................................................................................. 30 TABLE 7: SERIES AND PARALLEL CONFIGURATIONS (1 INVERTER) ........................................................................ 31 TABLE 8: DC ANALYSIS OF 3-INVERTER SYSTEM .............................................................................................. 33 TABLE 9: MODULE TO THEIR RESPECTIVE INVERTER ......................................................................................... 35 TABLE 10: INVERTER TO COMBINER BOX ....................................................................................................... 35 TABLE 11: CURRENT AT THE COMBINER BOX .................................................................................................. 36 TABLE 12: VOLTAGE DROPS FROM PCE TO THE MAIN DISTRIBUTION BOARD ....................................................... 36 TABLE 13: LIGHTNING RISK ASSESSMENT ....................................................................................................... 45 TABLE 14: VOLTAGE DROP CALCULATIONS (MINOR PROJECT 1) ........................................................................ 78 TABLE 17: TEST RESULTS OF SUN POWER MODULES ....................................................................................... 90 TABLE 18: DEGRADATION OF MODULES ........................................................................................................ 91


9

1 Introduction

The proposed site is located at Catalano Road, Canning Vale as indicated in Figure 1. The

proposed grid connected system will utilize both roof and ground mounting systems,

which will be illustrated in Figure 2. The final design consists of the following PV

equipment:

Modules:

5.04kW of Kyocera KD315GX-LPB on ground area (16 X 315W)

4kW of Sun power SPR-200-BlK on roof area (20 X 200W)

Inverters:

1 X SMA STP 5000Tl-20

1 X Fronius IG15

1 X SMA SB2500-TL

This 9.04kWp design will utilize all available PV modules to produce maximum amount of

power. The layout of PV and the inverters are illustrated in figure 2. Inverters are

strategically placed behind the walls and hidden away from the general public due to

security reasons.

There will be 4kW of Sun Power (SPR-200-BLK) modules placed on the roof of BE and

5kW (Kyocera KD315GX-LPB) modules on the BE barbeque area will house the ground-

mounted Kyocera modules.


10

Figure 1: Aerial view of site


11

1.1 Project Objective

The objective of the project is to acquire approvals, design, procure, implement and

commission the 9.04kWp before the end of the internship placement.

Besides giving our client the chance to take advantage of the REC scheme [31] and

provide monetary savings backed up by green energy, the ground mounted system will

also facilitate the rack assembly ground and act as a team building experience of Balance

Services Group over the course of implementation.


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1.2 Layout of PV

There will be 2 arrays as indicated in a drawn to scale drawing as indicated in Figure 2.

4kWp of Sun Power SPR-200-BLK located on the roof of BE and 5.04kWp drawn to scale

of Kyocera LPB 315-GX modules located on the outdoor barbeque area at BE. The

enlarged diagram on the right side of figure 2 indicates the location of the poles of the

racking system. Total system peak capacity is 9.04kWp DC and is handled by the 3

inverters mentioned in the introduction.

Figure 2: Layout of PV at Barclay Engineering


13

1.3 Company History

Balance Utilities Solution (BUS) is part of the Balance Services Group, along with Barclay

Engineering and Ugen to operate on the purpose for providing better platforms for

power generation solutions to enable more productive activity, with greater social

benefit, whilst being friendly to the environment.

In 2011[16], during a time where a growing need in the market for sustainable and

integrated energy was required, Balance Utilities Solutions was formed.

Direct experience where both manufacturers and customers showed their frustration

when service projects are not brought together to meet expectations. Balance Utility

Solutions, with its three principals (Rod Hayes, Terry Barclay and Mike Laughton-Smith)

has over 80 years of combined experience in utilities management, infrastructure

development, energy project management and delivery, and equipment fabrication and

installation, believe that a viable yet sustainable solution can be integrated into

genuinely sustainable long term solutions [16].

In 2012, Balance Services Group brought Barclay Engineering along with its industry

leading 35+ year track record project delivery of mechanical engineering and fabrication

[16], acting as a key contractor for the group.

As of 2013, Balance Utility Solutions stands with its industry leading engineering and

expertise in renewable energy. Expert knowledge of the system dynamics, covering the

lifecycle from design and approvals, procurement, implementation and commissioning

of diesel, gas, solar and wind generation, control systems, energy storage and water

treatment systems allows customers to define their expectations and be given a turn-

key solution [16].


14

2 Simulation tools

2.1 Homer

Homer is a useful software package [32] for feasibility studies but is only compatible

with Microsoft Windows and has the options to simulate and optimize systems capital

costs by using surface conditions from NASA surface meteorology.

It has a friendly user interface that incorporates sensitivity analysis towards capital and

operational and maintenance costs for Wind, PV, diesel, hydro and also hybrid systems in

both standalone and grid connected forms.

It also has the capability to include economic factors such as inflation, discount rates and

input current fuel prices for diesel or electricity charges to simulate the system

according to the users tariff of choice, making the simulation results resemble real life

situations to a very high level.

2.2 Trimble Sketch up

This is a useful software package [33] for doing site drawings and electrical drawings

due its interface with Google Maps. It is a capable program with many usable functions

that can enable the user to draw to scale 3D drawings and animation of shadings

depending on site location.


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3 Preliminary Authorization

3.1 Introduction

Preliminary authorization is the formality of getting approvals from the electricity

retailer (Synergy) and the electricity transporter (Western Power) especially if system is

to be grid-connected. The two applications that are required for a system to be

connected to the SWIS network will be discussed over in this chapter. A third

application form will need to be completed to claim the RECs available when the system

is completed.

3.2 The South West Interconnected System (SWIS)

The SWIS interconnected system is the utility network that provides electricity to all end

users of the network; Suitable application forms must be completed and approved to

gain authorization before additional generation can be connected to the grid.

There are two types of tariffs that electricity consumer’s fall under:

1. Contestable: electricity consumption of more than 50MWh per year -

consumers are then able to choose their electricity retailers;

2. Non-contestable: electricity consumption of less than 50MWh per year -

consumers are not able to choose their retailers.

BE is situated in Canning Vale in Western Australia, with coordinates (32.06S, 115,902E)

and is situated in the SWIS network. With an annual consumption of more than 50MWh

per year, it falls under the medium to large business tariff. Suitable application forms for

embedded generation are attached in the Appendix A3 and Appendix A4.

It was essential to complete the following two applications simultaneously along with

preliminary designs of the projects. The two authorizations that were completed and

approved during the second month of the project (October 2013) are:

1. Synergy: Non contestable bi-directional metering and embedded generation

service application;

2. Western Power: connect embedded generation to the Western Power network


16

3.3 Additional process of PV installations in the SWIS network

The following are the processes that were undertaken during the design. It is important

to do the design in the correct sequence. If there are no means for achieving a

satisfactory outcome of a particular step, the step before it has to be reviewed. The

following are the design steps with reference to WP guidelines.

1. Check if site is in WP approved list of suburbs (Appendix A12);

2. Choose modules to suit the application;

3. Choose inverter;

4. Check if inverter is in WP approved list


17

3.3.1 Synergy Application

As a requirement of a complete PV system, a bi- directional meter [21] must be installed

prior to system being grid connected. This is an essential step, because electricity will be

exported to the grid when it is not consumed. This step is also essential as part of the

WP application. Upon approval, the customer is issued a reference number. Application

can be found in Appendix A1. As stated by the retailer, an import/export sign will be put

on the new bi-directional meter once it is installed. Figure 3 is the actual site photo of the

bi-directional meter installed.

Figure 3: Bi-Directional Meter Installed


18

3.3.2 Western Power Application (Less or equal to 30kVA)

High level of technical information like cable sizing is also required as part of a

application. To simplify the process and make it more illustrative, a single line diagram of

the system was created via Trimble Sketch up [33] and cable loss calculations had to be

done as conductor size and lengths had to be chosen. During the application a single line

drawing was created (Appendix A10), and the final application is attached in Appendix

A2

3.3.3 Renewable Energy Certificates (RECs)

Early during the design phase, it is important to ensure that the PV equipment, PV

modules and inverter are in the clean energy council (CEC) component list, only

components that are new and listed in the CEC are eligible for RECs.

Under the jurisdiction of the Australian Federal Government, new PV systems have to be

certified by a CEC accredited designer and installer to be eligible for a small technology

certificates (STCs). STCs vary in price on a daily basis, and will also depend on the

location and date of the install. Module and inverter also have to be on the CEC

approved list of products if STCs are to be claimed [2][3].

The current market rate for subsidy is approximately $36.00 per STC (correct on 13 Jan

2014). This ground-mounted system has a capacity of 5.04kW and will be eligible for 104

STCs. The amount of eligible STCs is calculated from the Australian Government Clean

Energy Regulator [31]. Solar companies will usually implement this as a point of sale

discount to customers, or sell them at an open market.


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3.4 Summary

The three main applications for a system as such a that were completed for the grid

connected 9.04kWp system was the synergy embedded generation application, WP

embedded generation application and also the ENVIROBANK application which is

required for the claiming of RECs. The ENVIROBANK application was not completed, as it

requires a fully completed and commissioned project that is signed off by a CEC

accredited installer.

The first application that was completed successfully was the Synergy bi-directional

metering application. This application is essential for the WP embedded generation

application because upon approval the applicant is supplied with a customer reference

number as shown in Appendix A3. This application took 5 working days to be approved

and the reference number that was given in the approval letter stays valid for 60 days.

The WP embedded generation application was a slightly more complex application to fill

out as it involves basic design information in an aerial view of the site as attached in

Appendix A2.

Location

Capacity of inverters

Cable lengths

Cable diameters

The application was completed with reference to the application examples provided on

the WP site and was approved upon submission within 28 days after the application was

lodged. Upon approval the application stays valid for a period of 1 year till connection,

which is well within the expected finish date of the project.


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4 Feasibility Studies

4.1 Introduction

Feasibility studies must be supported with facts and the latest financial information that

contributes to the value of engineering. This information also contributes to good

project management where taxations and legislation are considered. There will also be

estimates for costs, selection of components for optimisation of costs to meet

requirements and also the project’s impact on the environment [15].

Each feasibility assessment is to deterministic for the cost effectiveness in multiple

circumstances, and each risk is identified in during this phase of the planning. Ultimately

reflecting on the profitability and the total amount of payback years.

Energy outputs of the PV arrays and total amount of savings generated from the system

are shown in the models in this chapter. Simulation data will ultimately affect the

payback period of the project. Payback period is calculated by the capital injected and

the amount of the revenue projected. PV projects require maintenance steps such as

clearing of vegetation and cleaning the modules. Output tests once a year if the system

is functioning properly, these can be eradicated from the program if a monitoring

system is installed.


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4.1 Resource Analysis

Sites with 5 kWh/ /d solar resource and above are generally regarded as a suitable for

PV installations. The calculated average daily radiation of the site 5.5 kWh/ /d, shows

that the solar resource is well suited for PV installation.

Clearness index is the amount of solar radiation that makes it to the surface and ranges

from 0-1 (fully overcast – Clear skies). BE has an annual clearness index of 0.633 which

Indicates that skies are relatively clear. Clearness index peaks in January at 0.708. The

range between the highest and lowest clearness index months are 0.184, and varies

between clear skies and slight overcast [18], which is well suited for PV systems. Figure 4

attached below is the HOMER solar resource inputs according to the latitude and

longitude as selected by the user.

Figure 4: Solar Resource (https://eosweb.larc.nasa.gov/sse/)


22

4.2 Financial Analysis

The Analysis is based on the data over the past 12 months (Aug 2012 – Aug 2013). Solar

resource data is acquired from HOMER and the total savings that can be generated from

the 9.04kW system is modelled with all modules facing true north and tilted uniformly at

30°. The tables and charts below graphically demonstrate the benefits of having the PV

modules installed. The simulation assume that all PV generated is consumed.

Table 1 below is the energy generation data that shows the energy reduction of the

system when installed; Table 2 is the table of monetary savings of on peak and off peak

tariffs. Graphical data is shown in Table 3; results show that the 9.04kWp system will

have an annual energy reduction of 8.39%. Table 4 is a graphical translation of on and off

peak savings that can be generated from the system.

This study is based on the Synergy p1 contestable business tariff; peak and off-peak

periods are as follows:

Peak (8am-10pm) weekdays: $0.39 per unit (kWh)

Off peak (10pm-8am weekdays; Saturday, Sunday): $0.10 per unit (kWh)

Table 1: Energy Analysis (https://eosweb.larc.nasa.gov/sse/)

Month PV

Generation (kWh)

Grid Energy Consumption

(kWh)


With PV (kWh)

Energy Reduction

Nov-12 1539.83 11422.41 9882.58 13.40% Dec-12 1600.05 18589.44 16989.4 8.61% Jan-13 1634.44 15205.78 13571.34 10.75% Feb-13 1609.87 15925.41 14315.54 10.11% Mar-13 1458.78 16807.7 15348.92 8.68% Apr-13 1214.37 16183.9 14969.53 7.50% May-13 959.06 15486.28 14527.22 6.19% Jun-13 846.49 17454.68 16608.19 4.85% Jul-13 881.28 16073.3 15192.01 5.48%

Aug-13 1079.88 21297.75 20217.87 5.07% Sep-13 1284.28 16807.87 15523.59 7.64% Oct-13 1457.42 11781.8 10324.38 12.37%

Total 15565.75 Average

Reduction 8.39%


23

Table 2: Off peak and Peak Savings

Month Off Peak Off Peak + PV On Peak On Peak + PV

Nov-12 $380.26 $327.96 $2,526.80 $2,123.54 Dec-12 $638.48 $589.79 $4,048.43 $3,587.11 Jan-13 $603.48 $557.78 $3,047.37 $2,562.18 Feb-13 $488.63 $444.64 $4,082.12 $3,661.70 Mar-13 $517.89 $470.65 $4,217.94 $3,807.85 Apr-13 $487.40 $453.97 $1,406.67 $1,058.71 May-13 $512.73 $486.93 $4,181.52 $3,891.95 Jun-13 $654.12 $618.73 $4,422.31 $4,225.55 Jul-13 $459.24 $441.22 $3,741.50 $3,453.87

Aug-13 $761.18 $731.05 $5,578.68 $5,256.72 Sep-13 $488.63 $453.32 $4,082.12 $3,713.98 Oct-13 $402.82 $359.69 $3,345.49 $2,920.51

Savings Summary:

Off peak savings: $459.12

Peak savings: $4417.27

Savings per year: $4876.39

Table 3: Energy Consumption

0.00

5000.00

10000.00

15000.00

20000.00

25000.00

Ene

rgy

(kW

h)


Before PV(kWh) After PV (kWh)


24

Table 4: Off Peak and On Peak Savings

$0.00

$1,000.00

$2,000.00

$3,000.00

$4,000.00

$5,000.00

$6,000.00D

olle

rs (

$)

Monthly Savings Breakdown

Off peak Off peak + PV On peak On peak + PV


25

4.3 Capital Costs

Under the jurisdiction of the Australian Federal Government, new PV systems have to be

certified by a CEC accredited designer and installer to be eligible for a small technology

certificates (STCs). STCs vary in price on a daily basis, and will also depend on the

location and date of the install [34].

The current market rate for subsidy is approximately $36.00 per STC (correct on 13 Jan

2014) [35]. This ground-mounted system will be eligible for 104 STCs [34], which will be

sold to an STC trader. The rebate from the STC will be passed on to BE as a discount to

the payment to BUS. The following is the itemized breakdown of the scope of BUS and

the client. This section is included in the business proposal; prices of the following items

shall not be disclosed due to the confidential nature of business.

Capital cost of the proposed system includes the following two sections:

1. Breakdown of design and equipment:

Engineering design

STP 5000TL-20-inverter

Balance racking system

Kyocera PV modules

STC Rebate

2. Breakdown of client payment:

Synergy Meter Upgrade

Balance of System (BOS)

Construction labour (50 hours)

Most of the balance of system (BOS) is already available at BE. The component list for

the balance of system is attached in Appendix A11.

The system lifetime is 20 years or more and will generate a total annual savings of

$4876.12; this however is subjected to increase as the electricity prices increases. Over

the projected lifetime of 20 years, the system will generate $87,768 ($4876.39 X 20

years) or more worth of savings.


26

4.4 Summary

This chapter was completed with simulation data with the aid of simulation outputs

from HOMER, which is a tool highly recommended due to its ease of use and the ability

to include economic data into the user interface. System capital costs are not included

in the report because of privacy issues, however it is an inaccurate way to value the

system and calculating payback periods because part of the system was bought second

hand and not eligible for STCs.

BE is situated in Perth, and being in the southern hemisphere and experiencing four

seasons in a year has an expected average solar resource of 5.5 kWh/ /d with its peak

months during the summer period and lowest solar resource during the winter months

(June). Clearness index is a relatively high at 0.633 with little variation throughout the

year, indicating that solar generation will be consistent and not be interrupted due to

overcast conditions throughout the year. The suitability for PV installs that are of such

size because BE is locked into the non-exporting business tariff, making it very beneficial

if all generation is consumed within the facility.

Electricity costs ever rising and the STC multiplier, for a certain location, the solar credit

multiplier, which was X4 in 2011, has now been changed to X1 for systems installed post

June 2013. In the near future, when PV is accepted as another form of “conventional

electricity generation” as the costs for production is lowered, REC schemes for PV

installs are also expected to be removed, making now a high time for the system to be

installed.


27

5 Design

5.1 Introduction

The original design proposed used a single 10kW 3 phase inverter, however due to the

design complications caused by the updates to clause 3.1 of the AS/NZS 5033:2012 where

string voltage should not exceed 600V, the design of the system was modified.

The final design documented from section 5.5 onwards included the use of two existing

single-phase inverters. To comply with the WP rule of having a phase difference of not

more than 2.5kVA, a 3-phase, 5kW inverter (STP-5000Tl-20) was included in the design,

which resulted the final design to be an unbalanced 3-phase system.

BE has already procured a 4kW set up comprising of 20X200W modules, and two single

phase inverters (SMA SB2500TL, Fronius IG15) inverters to support. The remaining

5.04kW of Kyocera modules will require a new inverter for the system to be connected.

Section 5.4 will discuss these issues and how the design did not conform to the

specifications of the inverter and Australian standards, particularly clause 3.1 of the

AS5033: 2012. The rest of the chapter (Section 5.5-5.10) discusses the approach to how

the final design was reached and the BOS sheet finalized.


28

5.2 Important Properties of PV Systems

5.2.1 Ingress protection

Ingress protection ratings (IP ratings) are important factors to consider when doing

electrical installations. Appliances that are to be used outdoors (Isolator box, junction

box, combine r boxes) all need to be IP55 or an IP55 rated enclosure needs to be used.

In reference to the AS60529, the IP rating is the specification of durability when exposed

to solid, liquid and mechanical objects to the electronic device. The equipment

manufacturers determine IP ratings after performing multiple tests [24].

The following are the interpretations of the IP rating:

First digit: Enclosure protection against solid objects [24]

Second digit: Enclosure protection against liquids [24]

Third digit: Enclosure protection against mechanical stress [24]

As a result of inverters not exposed to mechanical stress during their lifetime, the third

digit generally is not required for PV components because once the system is

commissioned; it is advisable not place items on top or near the components

IP 65: Totally protected from ingress of dust, can be hosed from all directions.

IP45: Access probe of not more than 10mm shall not penetrate can be hosed

from all directions.

IP ratings of 45 and 65 makes it an equipment which is quite versatile to weather

conditions however the inverters shall be placed in a shaded area where it would not be

under direct sunlight. Table 5 is the summary of the ingress protection ratings of the

inverters to be used in the install.

Table 5: Ingress Protection of Inverters

Inverter Ingress rating

SMA STP5000-TL-20 IP65

SMA SB2500TL IP65

Fronius IG15 IP45


29

5.2.2 Maximum Power Point Tracking (MPPT)

MPPT tracking is the electronic tracking of the best match between the supply and load

for optimizing power delivery. Without MPPT trackers, PV systems are only limited to

the loads which the system is connected to. The two common types of topology of the

inverter used in PV systems are the DC--DC buck or buck or boost converter or the DC-DC

converter [23] used only at the DC side for MPPT and having a transformer on the AC

side.

In a PV application, the mismatching conditions caused by partial shading or mix

matching of PV modules linked to the same input can be partially fixed by MPPT device

in the inverter by altering the DC input voltage of the inverter to provide the optimum

energy available from the system [22].

5.2.3 BI – Directional Meter

The Bi-Directional electrical meter enables the electricity retailer to monitor the usage

and charge the end user according to how much electricity is exported and imported.

This bi-directional meter for this project is installed by Synergy after the application has

been approved. The sticker on the main supply (Figure 3) of the site will have a sign

indicating that the Bi-Directional meter has been installed.

The client has to have the bi-directional meter installed because of the different tariffs

for import and exports for electricity [21]. Without the new meter installed, existing

analogue meters may spin backwards and give an inaccurate reading for the correct

amount to be paid [21].


30

5.3 Choosing an Inverter

Matching inverters and solar modules are important so that the power generated from

the modules is matched to the inverter and its operating voltage window. Cable is

selected through a process followed closely to the Australian Standards. Voltage drops

from the source and load to PCE of less than 3% [29].

The original approach (design 1) was to use a 1-inverter system, the Aurora PVi-10-OUTD

inverter was chosen because it requires less amount of space, if a monitoring system

was to be implemented, this would be a more viable option because only a single

monitoring system would be required. This option also is discussed in section 5.4.

Section 5.4.1 addresses the problems that were associated with the design as it

exceeded the maximum allowable Vdc of 600V in the AS5033 clause 3.1.

The Final design (design 2) utilizes 3 inverters. This was the most viable option as 2 out of

the 3 inverters were already available on site. A single 3-phase inverter SMA STP 5000TL-

20 was included in the design to accommodate the 5.04kWp ground-mounted system.

Refer to table 6 for a clearer view.

Table 6: Inverter Combinations

3 inverter

OR

2 inverter

OR

1 inverter

SB2500TL(available) STP 5000TL-20 Aurora PVI-10-OUTD

Fronius IG15 (available) SMA SB4000

STP 5000TL-20


31

5.4 Design 1 (1 inverter)

The single inverter was chosen, however to comply with AS5033: 2012 clause 3.1, the

system needed to be secluded from the general public. This was not a favourable choice

to our client due to the extra costs that may be associated to isolate the system. Table 9

indicates the string voltages of the systems in series and in an attempt to lower the

string voltage a parallel configuration was also considered.

In series configuration, the maximum string voltage of MPPT1 exceeds the upper limit of

MPPT1 and MPPT2. In parallel configuration, minimum string voltage of the rooftop

modules is 17.3V short of reaching the minimum operating range of MPPT1; string

current is also 0.4 A above the tolerable limit of the current rating of MPPT2. Table 7 is

the summary of the string voltages and currents for the entire system.

Table 7: Series and Parallel Configurations (1 inverter)


32

5.4.1 Issues and Solutions to design error

Issue:

After analysing the design in accordance with the inverter data sheets, it was found that

that string voltages were not within the MPPT range of the inverter specifications for

both MPPT 1 and MPPT2. When placed in a parallel configuration, minimum voltage was

out of the MPPT voltage window, which further confirms the need for a different design.

Possible Solutions:

1. Put strings in parallel to reduce voltage;

2. Exclude modules from the design to reduce string voltage;

3. Choose another inverter

As the string voltage was too high, the parallel combination had induced a nominal

current that was too high for many inverters in the market. A new 3-phase inverter (SMA

STP5000Tl-20) was included in the design along with the Fronius IG15 and SMA

SB2500TL.


33

5.5 Design 2 (3 inverter)

Because the BE is connected to a 3 phase grid supply, the SMA STP5000TL-20 is a 3

phase inverter and the Fronius IG15 and SMA SB25000-TL are both single phase

inverters. According to the WP requirement there should not be a difference of more

than 2.5kVA. This requirement is fulfilled with the current design, the 5kW inverter

relates to 1.67kVA per phase. Apparent power difference between the highest and

lowest phase has a difference of 0.83kVA. Table 8 is the DC analysis of the final design

and incorporates the temperature coefficients to a minimum of 5°C and a maximum

temperature of 65°C.

Table 8: DC Analysis of 3-Inverter System


34

5.6 Cable Calculations:

4 cables were used from the modules to the inverter. Cable lengths are illustrated

in Figure 5. The voltage drops were of less than 1% for each string to inverter, detailed

cable calculations for the DC side and AC sides can be found in Appendix A22. The

following are the formulas that were used for majority of the calculations:

Line to line current equation:

√

Using the formula above the line current of the Fronius IG15 and SMA 25000TL single-

phase inverters are found and added with phase a and phase b at the combiner box.

Step 1:

Step 2:

Step 3:

The AS5033: 2012 states that the total voltage drop of the system cannot exceed 3%.

Because of the complexity of the system the tables will be split into the following

sections, starting from the DC side of the system to the AC side of the system. Cable

calculations will be done from the modules to the inverter, inverter to the AC combiner

box and lastly, then from the AC combiner box to the main distribution board. These

tables illustrate the summarized data of the calculations that determine the size of the

cables that are to be used.

Table 9: Modules to their respective inverters

Table 10 Inverter to Combiner Boxes

Table 11: Combining the outputs of the single phase inverters to the three

phase

Table 12: Voltage drops from the PCE to the main distribution board


35

Table 9: Module to their Respective Inverter

Modules to inverter

DC cable Length (m) Cable diameter ( ) Voltage drop %

Kyocera 5.04kW 5 4 0.01

Sun Power 1.5kW 15 4 0.08

Sun Power 2.5kW 25 4 0.24

Table 10: Inverter to Combiner Box

Inverter to AC Combiner Box

Inverter Length (m) Cable diameter ( ) Voltage drop %

SMA STP 5000TL-20 5 4 0.246

Fronius IG15 5 4 0.005

SMA SB2500-TL 5 4 0.202


36

Table 11: Current at the Combiner Box

At the combiner Box

Phase Voltage (V) Current (A)

a 240 22.138

b 240 18.805

c 240 12.138

Table 12: Voltage Drops from PCE to the Main Distribution Board

Combiner Box to Main Distribution Board AC Cable

Length (m) Cable diameter ( ) Phase Voltage drop %

40 10 a 1.670%

b 1.210%

c 0.623%

According to the (AS3008:2009, clause 4.6), it is a safety measure to consider the

heaviest load when considering voltage drops and over current protection. Protection

on the phases with lower currents will leave the system without an appropriate buffer

for starting up currents and cause nuisance tripping on all the other 3 phases.

The 9.04kWp system contributes to the grid as a generator. Phase a carries the most

amount of current, therefore should be connected to the line that carries the most load

in BE. Phase b shall be connected to the line that carries the second highest amount of

current. Phase c as shown in table 13, carries the least amount of current and therefore

can be connected to the line with the lowest current. Figure 5 below is an illustration of

the distances of cable runs that were used for the cable loss calculations. It should also

be noted that the SMA STP5000TL-20 inverter is a 3-phase inverter, the outputs of the

other 2 single phase inverters are combined together as an unbalance 3-phase system.

Figure 6 is the single line diagram that was used to attain electrical quotes on the

system.


37

Figure 5: Overview of system

CombinerBox

Drawingisforillustra vepurposes,andisnottoscale

Kyocera5kW

SunPower1.5kW

SunPower2.5kW

FroniusIG15

SMASB2500TL

SMASTP5000Tl

Distribu onBoard

25m

15m

5m

5m

5m

40m5m


38

Figure 6: SLD and Breaker Specifications


39

5.7 Circuit breaker/Enclosure

Overcurrent protection measures used will be in the form a circuit breaker (CB). Each CB

shall be rated differently as this is a more complex system compared to the conventional

single or three phase PV installations. Components exposed to outdoor conditions are

to be at least IP 54 complaint or be put into IP 54 rated enclosures. All of the CBs with

the exception of the one at the main distribution board will require being in IP 65

enclosures.

As per AS5033, CBs are rated to 25% more than the Isc (maximum current that the array

experiences). The formula used to rate the CBs is as the following:

[29]

Because this is a combination of a three phase and two single-phase systems, the

protection CB at the combiner box must be rated in accordance to its highest line

current to accommodate. Fault protection devices to be used are all rated differently

and are to be indicated in the SLD in Figure 6.

Due to the cable lengths of the system from device to device, isolations points are

required whenever the inverter is not within sight. The roof-mounted system has

breakers included in the design (B1, B2) to comply with this standard.


40

5.8 Cable Routing and cable types

All 3 inverters are located behind the fence as shown in Figure 2. The reason for the

inverters being located there is due to possible future development of the site.

Copper cables are used as DC cables from the rooftop array and ground-mounted array,

adhering to AS5033 (clause 4.3.6.3.1). Isolation points (B1, B2) on the rooftop are

required and are shown in the SLD in Figure 6. Enclosures are to be located at a highly

accessible area and to be IP65 rated for the system to comply with the standards. All

exposed wires of the system shall be in a UV stabilized conduit. Cable diameter is

justified in section 5.6.

The distance from the inverters to the AC combiner box (IP65) is an estimated 5m

XLPE 3+1 core cable [8] per inverter prior connection to the AC combiner box (IP65, 6

poles). From the AC combiner box to the main switchboard, the distance will cover 40m

(estimated) and shall utilize cable no less than in diameter; slightly thicker

conduit (32 ) is used for the application. Cables are to be run along the fence line

and into the rooftop of the BE office, and into an empty port on the BE main distribution

board as illustrated in Figure 7.

Figure 7: Main Distribution Board


41

5.9 Lightning Protection Systems (LPS)

BE is located in an industrial area in Canning Vale, the area surrounding the installation

site consists of other factories and business without significant high-rise buildings or tall

trees. This leaves the array a potential lightning strike target. However, to determine

whether or not the building required LPS systems, a risk assessment must be done.

It is important to consider lightning protection systems (LPS) for PV installs. Areas with

higher lightning densities such as office buildings, schools and power utilities will include

both internal and external protection if there are high volumes of human traffic and

expensive electrical components.

5.9.1 External Lightning Protection

LPS systems are used to attract and direct the charge to its circuit rather than having

the lightning strike cause mechanical or thermal damage to its structure by providing a

low resistance path to ground where it gets terminated. External methods of

overvoltage protection are discussed briefly in the overvoltage protection section in

AS5033: 2012 clause 3.5.2 and Appendix F5 in the AS5033 [29]. External methods can

consist of earthing and bonding, magnetic shielding and cable/conductor routing; and

SPD protection [26]. Figure 8 below is also a method of wiring the modules as it

decreases the amount of loops in the cables, providing an alternative path for the

current to flow, protecting the modules against lightning [26].

If there are no means of external lightning protection at the site, internal protection

methods such as the appropriate placement of internal LPS can be used.


42

Figure 8: Prevention Of Wiring Loops in Circuits [26]


43

5.9.2 Internal Lightning Protection

The two forms of internal lightning protection that will be discussed are:

Equipotential Bonding

Surge Protection Devices (SPD)

Equipotential bonding is the bonding of all the ground to the same multiple earth

neutral connection (MEN connection). This will work by making all the equipment

bonded together have the same electrical potential. This enables the human being to be

able to touch two items with the same reference because it eliminates the potential

difference between them [27].


44

Surge protection is referenced to ground and provides an alternative route for the

current to flow to the ground. It operates by having two pathways for the current to

flow. During normal operating conditions, the flow of current goes to the load while the

other pathway is blocked by a bad conductive metal, which only conducts when a higher

voltage than average voltage is received (during overvoltage).

There are 3 protection levels in SPDs (Type I, Type II, Type III). Protection levels are in

descending order with Type I as the highest order of protection. While most inverters

already have a type II inverter within its internal circuit, surges can still pass through due

to the high operating currents of PV systems. SPDs shall be connected before and after

the inverter for overall protection of the inverter and BOS, details on where SPDs should

be installed and the range (10m) it protects can be found in the appendix of AS5033.

Although the final design does not include SPDs, it is recommended that the system

have the following protection installed:

DC side:

Type II SPD intercepts the circuit after the PV array and also at the point before inverter

for the rooftop arrays. Ground array only requires SPD at the point at the inverter as the

distance is between the PV modules and inverter is less than 10 metres.

AC side:

Type II SPD intercepts the circuit before the entrance of the building and also at the

point of the inverters.


45

5.10 Lightning Protection Risk Assessment

A lightning protection risk assessment has been conducted according to the lightning

man guideline. This guideline is a replicated version according to AS1768 which is

available online. The risk assessment incorporated the risk of the site where power

utilities are involved and human lives are at risk during a case where lightning strikes.

Risk to human life loss is low and a dedicated external LPS system is not required.

Factors considered in the lighting risk assessment are shown below in Table 13.

Table 13: Lightning Risk Assessment

Assessment Type of Structure

or use

Type of

Construction

Height of

structure

Prevalence/

Thunder

days

Situation

Description

Structure with

contents of fair

importance, e.g.

Water tower,

Shop with

valuable

contents, office,

factory or

residential

building

Reinforced

concrete or

steel frame

structure

with a

ferrous

metallic roof

Exceeding

6m but not

exceeding

11m

Exceeding 8

but not

exceeding 15

On the flat,

at any

elevation

Value of

index score 2 1 2 3 0

Total score 8

This risk assessment gives a total score of 8, which indicates that risk involved is

negligible and therefore LPS systems are not required. SPDs should still be included in

the final design if the budget is permissible. The full lightning assessment is attached in

Appendix A21.


46

5.11 Earthing

Earthing of the system is an important safety precaution that needs to be addressed for

onsite personnel and maintenance personnel; all conductive equipment must be

equipotential bonded; this included the racking of the system. The human perception of

an electric shock is 0.5mA [19]. A study at Murdoch University [19] recorded 0.6mA of

leakage current from a 2.25kWp array in its racking system, which further enforces the

need for the racking system to be earthed to prevent accidents from happening.

Earth Lugs are included in each individual rack to prevent the electric shock when a well-

earthed person touches the racking system. The flow chart in Figure 9 is a map to how

the earth conductor is chosen and implemented as shown in the SLD, in Figure 6.

All conductive material is to be linked to the same earth bar as the MEN connection of

BE. By doing so, all components will be equipotential bonded; this leads to the potential

difference between a well-earthed person and the ground to be of a much smaller

magnitude.


47

Figure 9: Earthing Conductor Selection [29]


48

5.12 Connectors

Connection points of the PV array and the inverters have to be lockable and only

separable when force is applied. Most new modules on the market today (MC4, Tyco,

Amphenol Helios H4) are lockable [29]. The ground mounted Kyocera modules already

come equipped with MC4 connections points from the junction boxes. The Sun Power

modules had MC3 connectors which are non-lockable and therefore needs to be

replaced. 20 male and 20 female MC4 connectors for the Sun Power modules are listed

in the balance of system sheet with a crimp tool to make the connections are included in

the BOS sheet as attached in Appendix A11.


49

5.13 Summary

This chapter takes into considerations of the installation guidelines of AS5033 and

regulations set out by WP for embedded generation. Voltage drop for the largest phase

was 1.69% while using a 10 cable from the combiner box to the main distribution

board (40m), a 6 cable was initially considered and had an voltage drop of 2.8%,

however it was avoided because the distance of 40m was a estimation and using the

6 cable would allow for no margin for error. Cable is to be routed from module to

the distribution board in conduit.

Initially there were a few design problems as indicated in section 5.4. However the

problems faced were overcome by changing the design of the system to utilize 3

inverters instead of 1 inverter. During this stage, the availability of the SMA STP 5000TL-

20 was also sourced from various distributors to get quotes on the cheapest price.

A lightning risk assessment was done for the site and the risk assessment is attached in

Appendix A21. The site is exposed to a mild risk of lightning strikes and therefore does

not need any form of external lightning protection. Internet protection like

equipotential bonding of the racking and the use of surge protection can be offered as

an option but are not required.

After completion of the design, a list of components that is required to complete the

system was finalized and the balance of system was formulated and passed on to the

on-site electrician for quote on the final pricing on the components. This was followed

by the preparation of a business proposal to our client, indicating the benefits and

system capital costs involved in implementing the grid connected PV system.


50

6 Procurement

6.1 Introduction

Procurement usually takes place after the detailed design is discussed and approved. It

is an important skill that project managers must have to increase the cost effectiveness

of the project.

When procurement is taking place, some important factors to consider are:

Are the items large in size?

When is the item required?

Will items obstruct workflow when they arrive on site?

Are the items sensitive to environmental issues (rain/ hail/ sunlight)?

What are the payment methods?

An example that can be used is given in minor project in minor project 1. This is a good

example because the arrival of PV modules should only arrive after site clean-up, ground

works are completed. Arrival of components, which are not required during the stage,

obstructs the flow of work that takes place and may cause delays. If component are

sensitive to exposure to environment, they will incur storage fees, which can all be

avoided if arrival of the materials are well timed.

6.2 Items To Be Procured

The following are the components that need to be procured:

SMA STP5000-Tl-20

New Roof Racking

Contractor for Concrete Cutting

Concrete for foundations of the system

Labour

CEC accredited installer sign off


51

6.3 Summary

This project did not proceed to the procurement stage of the project because of the

financial terms of the project have not been met.

Sub-contractors and the lead times associated for the components to arrive on site have

been acquired and implemented on the Gantt Chart for reference.

This phase of the project required prior knowledge of a systematic approach for the

project to flow smoothly. If well timed and planned can lower project overhead and

avoid delays.


52

7 Implementation

7.1 Introduction

This chapter involves the process of getting the installation crew to get started and the

job safety assessments (JSA) plans for the job to proceed. Site visits were mandatory, to

make sure of the availability of space. Trimble sketch up was a very good indicator for

area estimation however from the aerial view of the site as shown in figure 1, the shade

sails had been a problem when estimating points of where the lines of fencing is

situated.

During the site visit, the measurement of the area further affirms that fencing had to be

removed for the system to operate efficiently. Total required area for the site for the

installation of the system was 24.72 .

Consideration have also been given to the 4kW on the roof, however after the design

had been done, roof renovation commenced which may impose delays on the project.


53

7.2 Fencing Options

This section applies to the ground-mounted array, which has fencing to the north of the

system as illustrated in Figure 2. An estimated 30% of the cells will be shaded from direct

sunlight, during noon as illustrated in a not to scale drawing in figure 10. Current

technologies within the inverter, such as MPPT tracking and bypass diodes in the

modules are insufficient to enable the system from reaping the full benefits of a PV

install, ultimately decreasing the system efficiency and monetary value in savings.

As seen in Figure 10, the ground-mounted array will fit onto the proposed site with only

the removal of the fencing on the east. However due to the partial shading caused by

the 1.85m fence line to the north of the array, it is essential that this part of the fence be

removed for an optimized performance of the system; hence increasing the monetary

value of the system.

Figure 10: Shading From Fence

As part of the business proposal to BE, the client had to be notified that the fencing was

required to be removed for the ground-mounted system to be installed. The fencing is

1.85m high as shown in Figure 10 and will impose significant amounts of shadings to the

ground-mounted PV array. Three separate site layouts and possible restructure of the


54

barbeque area with their benefits and function listed was discussed among BUS

internally.

A PowerPoint presentation was prepared for the different fencing options available and

will be included in the Appendix 15-17, and the final decision was to leave most of the

fence intact and remove fencing on the north of the PV array that can cause shading as

indicated in Figure 11.

Figure 11: Desired Fencing Option


55

7.3 Ground-mounted racking system:

The floor of the installation site for the 5.04kW ground mounted system had concrete

set on it as it was an outdoor barbeque area for BE (Figure 12), the ground on the east is

paved by bricks and the allocated site for the piling the support beams of the 5.04kW

system had to be piled 1.5m into the ground as per installation manual of the racking

system.

In order for the installation to proceed, the vertical axis of the racking system (H beam),

had to be installed on the concrete part as indicated on Figure 12. The concrete is 85mm

(refer to Figure 13) at its thickest point, sand beneath. For small piles such as the poles

for the ground-mounted system, concrete squares of 0.2mX0.2m have to be cut out

with a circular saw before installation of the piles. A small excavator with a vibrator can

be used to vibrate the poles into the ground. An excavator can also use its bucket to

knock the poles into the ground however will cause damage to the tops of the poles and

cause issues with connecting the pole top and pole top connector.

Numerous piling contractors were contacted and due to the small scale of the job, many

established local piling contractors were not willing to accept the job, or gave very

expensive quotes. The cheaper solution of getting the foundations as shown in Figure 15

was to have the 85mm thick concrete cut out square blocks, the next step was

to manually dig the hole 1.5m deep and fill it with 0.5m of rapid set concrete.

Density of concrete = 2400kg/

Volume per base anchor =

Weight per anchor (kg) =

The base anchorage is approximately 48kg per pot. A total of 4 pots equalling 192kg of

concrete have to be used for the foundations of the racking system. Installation advice

on the improvised foundation was proposed, and recognized by the manufacturer.

Email correspondence with manufacturer is found in Appendix A19.


56

Figure 12: Before preparation

Figure 13: Thickness of Concrete


57

7.4 System Security

Security becomes an issue when the PV system is exposed to the public. There are

multiple solutions to prevent this from happening; however the modules are still

subjected to vandalism.

The following are the suggested methods that can be included as part of the package to

enhance security of the system:

1. Have motion sensor lights that cover the area of the modules

2. Have locks and chains at the back of the modules to decrease accessibility

3. Have security cables of the modules that trigger a security alarm when the

modules are moved

4. Secure the modules with one way security bolts

5. Insurance coverage for theft and burglary

7.4.1 Recommendation for Security of the System

It is recommended the stakeholder utilizes multiple security measures as mentioned

above. There are one way security nuts that can be replacements of the M8 bolts that

are attached to end clamps that hold the modules to the frame. This will be the most

crucial step to secure the system because this makes it impossible to remove the

modules individually without the use of a specific tool provided in the kit.


58

7.5 Summary

All stages of the implementation were sourced including quotes from external

contractors for the foundations of the racking system.

Currently the site has concrete flooring; it is not possible for the piling as recommended

by the manufacturers to be done, a different approach on how the foundations would

be set was suggested and approved by the manufacturers of the system.

Job safety is of high priority and standard industry safety protocols are implanted by JSA

plans. The assembly team consists of individuals from BE and BUS. Procedures for JSA

was acquired from the production manager at BE. Instructions are to be followed by all

members of the assembly team.

Security of the system is documented in section 7.4 and is highly recommended for the

ground mounted system and should be implemented because the design of ground

mounted system is assessable to general public.


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8 Commissioning

8.1 Introduction

Commissioning is set to take place when implementation of the system has been

completed. It is the procedure of “final checks” of the system to ensure that all

components are installed appropriately not only by the information provided by the

manufacturer, but also complies to the Australian Standards on PV installation.

Commissioning tests also act as an indicator to ensure that all components are

functioning to satisfactory levels and safety hazard issues are all rectified before the

project is handed over to the client.

Commissioning tests are to be performed by the CEC accredited PV designer, using the

commissioning equipment available at BUS and will be split into four main sections and

also its step-by-step instructions that is required to perform the commissioning.

1. Mechanical and structural inspection

2. DC Commissioning

3. AC Commissioning

4. Safety tests

The following documentation presents the commissioning procedure for the BE grid

connected PV system. The commissioning procedure is sectioned into two phases. The

first phase is a physical and mechanical inspection of the array and surrounding

components. The second phase is the electrical site acceptance testing of the PV

system.

The mechanical inspections includes the following:

Inspection of PV array installation;

1. Concrete foundation location;

2. General Site Arrangement;

Inspection of inverter enclosure.


60

The electrical testing includes the following:

Testing of each PV string at the Junction Box;

1. Earth/Ground Continuity Test;

2. Open voltage test, short circuit test;

Testing of each inverter;

Testing of AC connection at combiner box;

Testing of complete power system at the main distribution board.

8.2 Quality Assurance Testing

1. Factory assessment testing (FAT)

Factory assessment testing is the procedure that manufacturers put their products

through before it rolls out of the production floor (e.g. flash testing on solar modules)

2. Site assessment testing (SAT)

On site testing for function as described by manufacturer, there are different

procedures in completing this test. This is determined by the assembly team/contractor

(e.g. on-site physical inspection of equipment)

3. Commissioning

This is the last stage of quality checks which is done by the CEC accredited PV designer

and the installer. Mechanical and electrical testing of a fully functioning system is tested

before it is connected to the grid.


61

8.3 Commissioning Test Instructions and Test Sheets

The Commissioning Test instructions and Test Sheets are located in Appendix A14.

8.4 Summary

Commissioning of the system was not possible during the timeframe of the internship

project. However the commissioning test instructions and test sheets have been

formulated and ready for when the commissioning is to be done on the system. This will

only be possible once a financial agreement has been made with the client and the

system has been completed.

Implementation of the system is due to be started by February and is due to be

commissioned by the end of the Feb 2014. Completed commissioning test data will then

be handed over to the client for early detection of an underperforming system.


62

9 Future Plans and Recommendations

9.1 Introduction

Considering the standalone inverter SMA Sunny Island 5048 (SI), battery banks have

been pre acquired together with other PV equipment, further development of the site

for UPS capability can be done with low capital costs.

BE has an onsite back-up generator that currently needs to be manually switched on

during blackouts. Blackouts can occur without notice and can cause valuable

information to be lost and business operations to come to a halt while waiting for the

generator to come online. An integrated system with battery banks and a backup

generator can be implemented using an uninterruptable power supply (UPS) system.

A conceptual design of the standalone/ grid connected hybrid system is documented in

this chapter.


63

9.2 Sunny Island 5048

The SI is a much more sophisticated inverter when compared to the grid connected ones

that are used in the main project. The inverter alone has multiple functions that are

listed below (Appendix A24):

Grid monitoring

Grid forming

Control of frequency and voltage

AC to DC conversion for battery charging

DC to AC conversion for load supply

Load and energy source control

Generator control capability

202V - 253V AC voltage

Under WP connection rules, standalone inverters such as the SI cannot be grid

connected; this is due to the non anti-islanding capabilities of the inverter. When the

grid is online, the SI acts strictly as a charger for the batteries from the supply of the grid

while not supplying any loads; its internal programmable logic control (PLC) can also be

configured to operate the utility grid and generator mutually exclusively with

coordination settings for a seamless transition between utility grid and back up

generation.


64

9.3 UPS Systems

UPS systems are widely used to provide temporary power supply for the system when

there are power shortages or blackouts. Their support time is limited to the capacity of

the battery. UPS systems are usually wired in to telecommunication systems or network

server pc, as they are the most important in organizations in scale, data processing

machines to provide ample time to back up devices and prepare for downtime.

Generators and UPS systems are forms of back up for existing power systems; the big

difference is the continuity of the power. The internal PLC within the Sunny Island 5048

can provide control during blackouts and can direct the site to receive power supply

from the generator and PV supply.

During the transitional period of normal operating conditions and stand-by generation,

usually by diesel generators, there will be a down time as opposed to UPS systems. This

is because generators are manually started or have electrical starters with its associated

PLC signal. During an unexpected power shortage event, dedicated loads can receive

supply from the batteries while the generator becomes a substitute for the grid. The

switching period is 16ms [30], which is less than a cycle of Australian electric power

network frequency of 50 HZ. This is sufficient for a seamless switching of supply.


65

9.3.1 Operation of UPS systems

The proposed UPS system consists of a dedicated UPS load, standalone island inverter

and battery banks and a voltage rectifier/charger and PLCs with its input sensors getting

feed from the grid. The following are the statuses and operations of the main

components (generator, PV and utility grid of the UPS system) during normal operation,

during a blackout and grid reconnection [30].

Before switching:

During normal operation, the load and UPS both receive supply from the grid while the

grid charges the battery bank via the SI.

During Switching: transient period

During downtime, the microprocessor of the SI detects a no signal from the grid and

diverts to backup supply (battery) while it signals the generator to be started up.

During Blackout

During the blackout, the utility grid is disconnected and the facility is islanded. The

facility is running from the generator supply and PV if available. Charging the battery can

be optional, depending on the generator capacity and the load required. The SI

continues to monitor to the grid for a signal.

Grid Reconnection:

When the PLC detects the availability of the grid, it will signal the generator to ramp

down its output while it matches the grid voltage. Once the grid is reconnected the

generator can go into standby mode and later on be turned off.


66

9.4 Summary

With most of the expensive components already procured by BE, the development of a

test bench will only inflict a low capital cost to BE. The majority of the costs that BE will

incur will be for the detailed engineering design, and testing of the existing components

such as Sunny Island 5048, 1MW load, battery banks and design involved. Due to the

lengthy period of which the battery has been left without charge, there is a possibility

that the battery banks will need replacement.

Developing a UPS system that supports the two main components of a business;

telecommunications and the main PC for business operation can be very beneficial. This

enables the business to receive enquiries, process payments during blackouts, making

this a very feasible option for the completeness in power supply of the facility. A

monitoring system is highly recommended to provide more efficient fault finding.

Advanced systems that are available in the industry also support SCADA interfaces.


67

10 Minor project 1 – Technical design of 150kW system

Having worked on the technical design of a 150kW wastewater treatment plant PV

project that is due to be completed during May 2014. Due to a last minute decision to

prepare the tender document for the project, a tight timeframe of 5 days was given to

complete the document.

A first meeting was held to distribute the workload and the author picked up section

“demonstrated understanding” which consists of the fundamentals of technical design,

project delivery and the materials used. Skills that were learned from my internship so

far were truly tested in the level of detail and consideration that is required for the

tender document to be completed. Two versions of the Gantt Chart (high level and low

level) were also implemented over the course of the minor project. The high level

version submitted together with the tender, while the low level version were attached

in Appendix A20.

The scope that was covered during the tender documentation is as follows, and further

details will be provided over the following chapter documented in the sections as listed

below [7]:

1. Demonstrated understanding of the scope of work

2. The process of delivery of goods and services

3. Various approvals for the system

4. How did the products meet the specific requirements of the project?


68

10.1 Demonstrated understanding of the scope of work:

Balance Utility Solutions will be undertaking the following scope of works for the 150kW

PV System consists of the following components.

Supply of quality power components including:

o Photovoltaic (PV) modules

o PV inverters

o Racking and ground mount structures

o Balance of system (Including cables, cable tray, switches, protection

devices, junction and combiner boxes)

o Communication gear

o Power protection relay gear (Balance Grid Integration Box)

o Switch room ancillary components (including air-conditioning

components)

Detailed electrical engineering design for the commercial PV System;

Site inspections and grid connection application;

Site leveling and clearing;

Installation of ground mounted PV racking system (North Facing);

Securing of the PV modules to the racking system;

Connection of DC cable and cable tray installation;

Installation of PV Inverters in switch room;

Installation of air-conditioning within switch room;

Installation of communication gear;

Installation of ancillary boxes (DC Junction box and AC Combiner Box);

Interconnection of AC Cable from Combiner box with existing switch board;

Installation of main solar supply switch;

Commissioning of PV system;

Commissioning of communication system;

Application of initial Large Generation Certificates (LGCs);

Operator Training and Assistance.


69

10.2 Process of delivery of goods and services

This section involved a detailed consideration of all aspects of the project, which was

categorized in the following 4 steps:

Step 1: Engineering design and approvals

Resource evaluation

Performance evaluation

Cost of equipment

System design

Components of BOS

Complying to principle expectation

Western Power grid connection application

Safety induction training

Step 2: Procurement

7 X Aurora TRIO-20.0-TL-OUTD-S2-400

1 X Aurora PVi-10-Tl-OUTD

Cable tray

Inverter mounting plate

Concrete footings

Racking system

600 X 255W HanWha SolarOne HSL6060p6-PB-1-255E PV modules

Hiring out of site equipment

Making of concrete blocks

Step 3: Implementation

Site provided free and clear of scrub

Site surveyed for placement of blocks

Placement of concrete blocks

Installation of cable trays

Assembly of racking system

Installation of PV modules


70

Electrical cable installation

Installation of Inverters

Installation of GIB

Installation of control and monitoring equipment

Clearing of site

Step 4: Commissioning

Civil ITP (Inspection and Test Procedure)

Structural ITP

Electrical ITP

PV DC Commissioning

Inverter Commissioning

Control Commissioning

Monitoring Commissioning

CEC PV system sign-off

Training and Handover


71

10.3 Approvals for the system

The application process is for connecting transmission loads and large generators to the

WP Network. The Process involves 6 stages and is done with collaboration with WP; the

following are the 6 stages and a brief description of theirs tasks and application

components that need to be submitted are indicated. This magnitude of generation

(above 30kVA) requires depth of detail during the application and involves mandatory

protection relays as part of the design requirement. Figure 14 is a more illustrative view

of the application stages that are required.

1. Enquiry

Identify suitable network connection point and feasibility, a submission of

lodgement fee is also due.

2. Project initiation

Identify network constraints and its options to modify network. Submission of

the corrected application and technical data with lodgement fee is required.

3. Project Scoping

Selecting final technical solution to be implemented. Adhering to technical and

safety requirements of the SWIS network. Preliminary designs such as computer

models, environmental assessments and project planning definition are

included. Identifying the CAG solution is mandatory at this stage. Submission of a

preliminary access offer is required.

4. Project Planning

This step Involves project planning, business cases and estimates of the project,

and also submission of the final technical solution to modify the network.

Statutory approvals are finalized. Submission of Access offer is required.

5. Construction & commissioning

The IWC (Interconnection works contract) then constructs and commissioned by

Western Power. Checking against the compliancy regulations for performance

verification and model validation.


72

6. Operation

Once constructed, the new and modified connection assets become the

property of Western Power. Assets can now begin operating under the terms of

the electricity transfer access contract (ETAC), which is a operation to facilitate

the construction of a connection or technical compliance [36].

Figure 14: Flow of Application for generator up to 150kVA


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Competing Applications group (CAG)

For systems upwards of 30kVA, the network has to be upgraded to accommodate the

change. The Competing Applications group (CAG) is a network solution that involves all

consenting parties to pay processing fee, which covers the following [28]:

Developing the shared network solution;

Preparing a preliminary design and cost estimate for the solution;

Undertaking system studies (such as load flow and dynamic studies);

Undertaking a regulatory test (where applicable);

Conducting a net benefits assessment (where applicable); and

Developing a project schedule and the likely costs to implement the solution if it

is accepted.

Terms and conditions for the applicants of the CAG [28]:

Preliminary offer is an upfront payments for the applicants in a CAG, the

acceptance fee is non refundable unless WP does not make an access offer.

Once sufficient funds are received, access offers will be created.

When the POA is being developed, any fees paid will not be refunded to the

applicant and will contribute towards overall costs to develop the POA of the

CAG.

If there is insufficient response and access offers are not issued, WP will proceed

and use the funds for development and refund the remaining after the rework.

POA offers will include technical information and costs for all the CAG

participants, information such as land acquisition; planning and environmental

issues are included.


74

4. How did the products meet the specific requirements of the project?

Design:

Inverter:

7 X Aurora TRIO 20KW-TL

1 X Aurora PVI-10kW-TL-OUTD

Racking system:

Figure 15: Concrete Footings

The ground mounted racking systems are custom made for every system and are

designed to comply with the following standards as shown in Figure 16:

1. AS1170.2 Structural design actions – Wind loads

2. AS1664.1 – Aluminium Structures

3. AS4600 – Cold Formed Steel Structures

4. AS3798-2007 – Guidelines on earthworks and commercial and residential

developments

PV modules:

255W modules will be utilized for the ease of installation and transportation. Associated

requirements as per request to tender document.

Configuration:

There are 15 rows of modules that resemble Figure 4, All modules are in portrait form,

containing 20 columns of 2 rows. The total amount of modules is 600. A total of 602

modules will be bought, however 2 will be used as spares.

This is designing with respect to the Vmax of the inverter; the inverters are rated to 1000V

per input string. However there is an option if the site has to allow for public access, the

configuration has to be changed to allow string voltage to go below 600V as per

AS5033, clause 3.1


75

Monitoring system components:

Aurora Enviro Sensors Entry

AuroraMAX Logger

Aurora Hand Held Display

a) Proposed installed location;

Trimble sketch up was used to draw the site location and the switch room layout. There

were two options that were given by principle on where the locations of the inverters

and combiner boxes were to be located: in the switch room or out in the field. The

option of having the PV equipment in the switch room was the preferred method of

install, however as space was a constraint for the set up, test fitting of the 8 inverters,

the BUS designed grid integration box (GIB), air conditioner was also considered to

compensate for the heat dissipated from the inverters.

Benefit of having equipment in the switch room:

Lowering of capital costs by eliminating the need for inverter enclosures;

Site layout

The tilt angle is 25 degrees and the space in between rows of modules is 1.35m. The PV

array takes up a total of 1276 , including the space in between each row of modules.

Beside both sides of the array, there is also space in excess of 8m, which allows for easy

access for service vehicles. Actual site drawing is located in figure 17.

Figure 16: Site layout


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The wall layout on the 13m by 2.7m wall in the switch room has the following layout: a

new 3.5kW air conditioning unit is placed in the middle of all equipment to compensate

for the amount of heat dissipated from the inverters. The switch room layout is

illustrated in Figure 18, with the inclusion of a 3.5kW air conditioning unit to dissipate

heat.

Figure 17: Switch room layout


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f. Wiring losses;

As Option 1 is chosen as the BUS preferred method of install for optimized performance.

The calculations are done from the furthest end of the PV array to the back of the switch

room, covering a total distance of 80m, voltage drop and power loss calculations for a

6mm2 Copper tinned cable with a resistance value of 3.11 Ω/km. String voltage of 616V

and nominal current of 8A is applied for the calculations shown on Table 14.


78

Table 14: Voltage Drop Calculations (Minor Project 1)

Strings Inverter Length (m) Cable Power Loss Power Loss % Volt Drop Volt Drop %

1 1 50 0.1555 19.904 0.20% 2.488 0.40%

2 1 50 0.1555 19.904 0.20% 2.488 0.40%

3 1 58 0.18038 23.08864 0.23% 2.88608 0.47%

4 1 58 0.18038 23.08864 0.23% 2.88608 0.47%

5 2 64 0.19904 25.47712 0.25% 3.18464 0.52%

6 2 64 0.19904 25.47712 0.25% 3.18464 0.52%

7 2 72 0.22392 28.66176 0.28% 3.58272 0.58%

8 2 72 0.22392 28.66176 0.28% 3.58272 0.58%

9 3 80 0.2488 31.8464 0.31% 3.9808 0.65%

10 3 80 0.2488 31.8464 0.31% 3.9808 0.65%

11 3 88 0.27368 35.03104 0.34% 4.37888 0.71%

12 3 88 0.27368 35.03104 0.34% 4.37888 0.71%

13 4 96 0.29856 38.21568 0.37% 4.77696 0.78%

14 4 96 0.29856 38.21568 0.37% 4.77696 0.78%

15 4 102 0.31722 40.60416 0.40% 5.07552 0.82%

16 4 102 0.31722 40.60416 0.40% 5.07552 0.82%

17 5 110 0.3421 43.7888 0.43% 5.4736 0.89%

18 5 110 0.3421 43.7888 0.43% 5.4736 0.89%

19 6 120 0.3732 47.7696 0.47% 5.9712 0.97%

20 6 120 0.3732 47.7696 0.47% 5.9712 0.97%

21 6 128 0.39808 50.95424 0.50% 6.36928 1.03%

22 6 128 0.39808 50.95424 0.50% 6.36928 1.03%

23 7 136 0.42296 54.13888 0.53% 6.76736 1.10%

24 7 136 0.42296 54.13888 0.53% 6.76736 1.10%

25 7 144 0.44784 57.32352 0.56% 7.16544 1.16%

26 7 144 0.44784 57.32352 0.56% 7.16544 1.16%

27 8 152 0.47272 60.50816 0.59% 7.56352 1.23%

28 8 152 0.47272 60.50816 0.59% 7.56352 1.23%

29 8 160 0.4976 63.6928 0.62% 7.9616 1.29%

30 8 160 0.4976 63.6928 0.62% 7.9616 1.29%

Summary

Power Loss 1242.01W

Power loss (%) 0.81%

Average Volt drop 0.84%


79

Potential issues associated with the specific project and how they will overcome.

Issue:

Delays in Western Power Approval

Solution:

Application for Western Power grid connection shall be completed and submitted one week

from the date of when the tender is deemed successful. Previous projects and experience

will enable Balance Utility Solutions to gain approval for the application in a fast and efficient

manner.

Issue:

Illness

Solution:

Balance Services Group is the parent company of Balance Utility Solutions, along with Barclay

Engineering and Balance infrastructure. With capabilities for all aspects of the project to be

done in house. Project continuity will not be affected and personnel’s with multiple skill sets

can easily be arranged within the group.


80

10.4 A project schedule/timeline

This aspect of the tender document greatly relied on the lead times associated with the

logistics of the equipment. All aspects of the project have to be considered in detail for

an accurate project handover date to be estimated. Suppliers and manufacturers were

contacted for numerous aspects of the system for an accurate estimate of lead times

Involved for equipment to arrive on site. Two Gantt Charts were created; a summarized

version was included in the tender document, and the detailed version, which will be

handed over to BUS for future project management duties. The high level Gantt Chart is

attached to this document as Table 15.

The low-level Gantt Chart involved the internal meetings, site visits, dates for booking of

flights and arrival of the site engineers and installation team. The low-level Gantt Chart is

also attached on Appendix A20 created a more realistic estimation of time required for

tasks to be done, yet enhancing the level of accuracy compared to the final cost of the

project

Design and Analysis of Commercial 84 Photovoltaic Systems and Components

Table 15: High Level Gantt Chart of Minor Project 1


11 Minor project 2 – Testing of Sun Power Modules

11.1 Introduction

The Sun Power modules that were to be installed on the rooftop of BE were purchased

second hand from a company that was liquidizing in WA. These modules have been

operational for 3 years and put in storage in BE for another 2 years.

The Sun Power modules SPR-200-BLK (Appendix A9) were very high-end PV modules.

With breakthrough technology and industry leading module efficiencies of 16.1%. There

are a total of 21 modules to be tested and the objectives of testing is listed in section

11.2.

11.2 Objective of Testing

The main objectives of the testing are:

Familiarization of commissioning gear for future use

Compare the degradation of the modules against published results

Find the 20 best performing modules to include in the design

Study of degradation when in Australian climate


11.3 Background

A study of degradation rates of PV technologies done by National Renewable Energy

Laboratory (NREL) shows a mean degradation rate of 0.8% per year [20] and 78% of data

points from a sample size of 2000 indicate a degradation rate of less than 1% per year

[20]. From the study alone, it is perceivable that not only climate will have an effect on

the degradation rates of the modules and system and also to take into consideration the

components used and installation location.

Studies from the NREL indicate that the degradation rates can vary from close to 0% in

(Vulcana, Italy) to 1% per year when placed in the desert in Libya [20], which shows the

sensitivity to climate conditions. Table 16 below is a study done by the NREL on the

average degradation rate on different cell technologies.

Performance output warranties allow for a power output degradation of 10% for 12 years

and 20% for a period of 25 years.


Table 16: Test Results of Sun Power Modules


11.4 Method

The testing of the modules is a straightforward process and can easily be done by using

a conventional multimeter. The following are the steps that I followed to achieve the

test results.

Before executing tests on the PV modules, all of the instruction videos on how to

perform the commissioning tests were viewed and notes taken on how to operate the

Seaward PV150 and Seaward 200R commissioning gear.

1. Locate a site to test the modules (non obstructing to operations of BE, exposed

to sufficient sunlight)

2. Wipe down access dust and effects of long storage periods

3. Create boundary on where the modules shall be placed

4. Record serial number of all 21 modules

5. Sync the Seaward PV150 and Survey 200R modules

6. Align the Survey 200R with the modules using the extension bracket provided

7. Record ambient temperature and module temperature

8. Connect the MC connector clips to the rear of the modules outputs (Red to

positive and black to negative)

9. Record Isc and Voc as shown in the Seaward PV150

10. Put the modules back into storage

11.4.1 Data Processing

1. Sets up tables with data in excel

2. Using ratios, Bring the outputs of Isc and Voc in reference to STC

3. Include Isc and Voc temperature coefficients to the measured ambient

temperature

4. Calculate the Power output of the modules by using the formula

5. Make an assumption that all modules have a 200W output

6. Calculate degradation of the modules


11.5 Results

There was only enough room for 5 modules to be lined up in a row as the testing was

conducted outside the storage area of BE. Results were acquired at 36°C on the 7th of

November 2013, according to the method mentioned in secti0n 11.3. Irradiance levels

were recorded periodically during the swapping of modules. A slight overcast condition

when testing modules 17-21, which caused irradiance levels to lower. The test data with

the Voc and Isc along with the testing conditions are recorded in Table 17. Table 18 shows

the degradation rates for 18 out of the 21 modules.

Note: Degradation rates for modules 2,3 and 8 could not be calculated because they had

broken connectors and was dangerous because of the high current levels.


Table 17: Test Results of Sun Power Modules

Irradiance level 932,944,900,880 (refer below) W/m²

Outdoor conditions Sunny, partly cloudy

Ambient/module temperature

36, 39 °C

Test equipment Seaward pv150, Survey 200R

Notes:

- Modules are tested at the following irradiance levels: - Modules (1-4): 932 W/m²; - Modules (5-12): 944 W/m² ; - Modules (13-16): 900 W/m - Modules (17-21): 880 W/m²; Modules 2 and 3 had broken connectors

Module Type Sun Power Date: 7/11/2013

SPR-200_BlK

Module number Serial number Isc (A) Voc (V)

1 C42j00256521 4.5 A 41 V

2 C43j00261609 - 41 V

3 C34j00220294 - 42 V

4 C07joo101467 4.8 A 41 V

5 C33j00215116 4.2 A 43 V

6 C38j00244946 4.3 A 43 V

7 C04j00094525 4.3 A 43 V

8 C46j00280987 - 43 V

9 C42j00256520 4.0 A 43 V

10 C43j00261613 4.1 A 44 V

11 C38j00244947 4.2 A 43 V

12 C42j00256524 4.2 A 43 V

13 C06j00097598 3.7 A 43 V

14 C42j00256522 4.0 A 41 V

15 C38j00244943 4.2 A 43 V

16 C33j00215124 4.1 A 42 V

17 C43j00261614 3.6 A 42 V

18 C38j00244944 3.8 A 42 V

19 C36j00230469 3.7 A 43 V

20 C07j00101478 3.6 A 43 V

21 C44j00271411 3.8 A 42 V


Table 18: Degradation of Modules

Each module is 200W

Module Delta Isc Delta Voc Power Degradation

( A ) ( V ) Degraded (W) Percentage

1 0.54 4.88 2.642060435 1.321%

2 4.88

3 3.88

4 0.22 4.88 1.06969992 0.535%

5 0.92 2.88 2.654152906 1.327%

6 0.81 2.88 2.348559685 1.174%

7 0.81 2.88 2.348559685 1.174%

8 2.88

9 1.13 2.88 3.265339346 1.633%

10 1.03 1.88 1.933766465 0.967%

11 0.92 2.88 2.654152906 1.327%

12 0.92 2.88 2.654152906 1.327%

13 1.26 2.88 3.629334827 1.815%

14 0.92 4.88 4.517245938 2.259%

15 0.70 2.88 2.02666816 1.013%

16 0.81 3.88 3.160845938 1.580%

17 1.28 3.88 4.965904524 2.483%

18 1.05 3.88 4.082995433 2.041%

19 1.16 2.88 3.359795433 1.680%

20 1.28 2.88 3.687613615 1.844%

21 1.05 3.88 4.082995433 2.041%

Average 1.530%

Minimum 0.535%

Maximum 2.483%


11.6 Summary

Monocrystaline-Si modules have been in used since the 1970’s and the amount of data

samples shown on Table 16 shows the amount of data points pre and post year 2000.

The degradation of the Sun Power modules has been calculated based on the

assumption that all modules are exactly 200W.

The key findings of the testing are:

Modules 2,3,8 cannot be tested due to having missing connectors (possibly

detached during de-commissioning);

Degradation rates were 0.02% higher than the NREL study;

Module 17 has the highest degradation at 2.483%;

Module 4 has the lowest degradation at 0.535%;

Average degradation of the 18 modules is 0.38%

The possibilities for the substandard degradation rate can be due to the following:

Power tolerances were not included in the calculation;

Dust was present on the surface of the modules;

Light induced degradation is highest during the first year of exposure


12 Overall Conclusion

There are numerous official standards and applications for PV installation. Both the

major and minor projects have been designed and handled with care, and the final

designs were very cost effective. This is due to the use of second hand and new

components in the overall system.

Over the course of this internship, there have been numerous experiences with

corresponding with contractors, broadening my professional network while also

deepening my understanding of the Australian standards used in the solar industry.

Due to the short timeframe and 100kW project commissioning in Guam and the

commencement 6MVA back up generation at Perth Market Authority (PMA), this

project is up to the procurement stage and once the client accepts the quote,

construction of the site can commence.

13 Learning Experiences

This internship project was collaboration between Murdoch University and Balance

Utility Solutions to design and project manage 9.04kWp PV system for Barclay

Engineering. There were other tasks such as preparing of tender documentation and

also soil resistivity testing of Perth Market Authority (PMA) and projects involved with

provided a very insightful experience on how versatile professional electrical engineers

must be.

Many valuable experiences have been gained from this internship project including the

familiarization of PV authorization approvals for PV systems of less than 30kVA and also

the application of PV installs up to 150kVA, which fall under the LGC scheme.

Liaising with contractors and getting quotations for items has enabled one to build a

professional network outside of university. Participating in tender documentation of the

minor project in tight time frames has truly let me experience working in a team under

pressure to meet deadlines of projects.


It is also learnt that for a system to be Clean Energy Council (CEC) approved, the design

has to be certified by a CEC accredited PV designer, and the installation must be

supervised or installed by a CEC accredited installer.


14 Annotated Bibliography

1. Australia, Standards. “As5033 Installation and Safety Requirements for

Photovoltaic (PV) Arrays.” (2012).

This is the standards for installation and safety requirements for photovoltaic (PV)

arrays. It covers issues for safety requirements and safety gear that is required for the

PV install.

2. Australia, Standards. “Electrical Installation” In Part 1.1: Cables for alternating

voltages up to and including 0.6/1 kV - Typical Australian installation conditions. Sai

Global Limited, 2009.

This standard has examples of LV cables cable selection for Australian installs. This

standard also has cable routing options and suitability of conductor for its respective

use.

3. Dirk C, J, and S R. Kurtz. "Photovoltaic Degradation Rates - an Analytical

Review." Progress in Photovoltaics, no. Research and Applications (2012).

This journal enlightens about the different cell technologies and how different

technologies can affect the degradation rate of the modules.

4. “Horizon Power, Western Power” Western Australian Distribution Connections

Manual.” 2013.

This connection manual provides a touch of every aspect of the Western Australian

distribution network. It also created a link for installers and consumers. WADCM

contains typical circuit diagrams for a clearer vision of the circuit.

5. Paskulich, John. Photovoltaic Grid Connect Systems Design. Central Institute of

Technology, 2011.

This book contains all the factors that need to be considered when designing a grid

connected PV system. However its limitations are that pre-acquired knowledge was

required. A guideline on preliminary system design is included.


15 Reference

[1] “Can I choose my retailer?,” Economic regulation authority – Online

http://ret.cleanenergyregulator.gov.au/Certificates/Large-scale-Generation-

Certificates/about-lgcs [Accessed 16/11/2013]

[2] CEC, approved inverter, PCE list, November 2013- pg54 [Accessed 17/11/2013]

[3] CEC, Approved module, PCE list, November 2013- Pg55 [Accessed 17/11/2013]

[4] Paraskevadaki, E.V.; Papathanassiou, S.A., "Evaluation of MPP Voltage and Power of

mc-Si PV Modules in Partial Shading Conditions," Energy Conversion, IEEE Transactions

on , vol.26, no.3, pp.923,932, Sept. 2011 [Accessed 08/12/2013]

[5] England, B. (2012). An investigation into Arc Detection and fire safety aspects of

photovoltaic installations. School of Engineering and Energy Murdoch university.

[Accessed 17/08/2013]

[6] Paskulich, John. Photovoltaic Grid Connect Systems Design. Central Institute of

Technology, 2011. [Accessed 09/109/2013]

[7] K, City of K. "Request to Tender ." 2013. [Accessed 15/11/2013] [8] Olex. "The Handbook." 2012. [Accessed 09/09/2013] [9] Horizon Power, Western Power. "Western Australian Distribution Connections

Manual." 2013. [Accessed 10/10/2013] [10]Lee Joo Shen, Tanvi Gupta, Daniel Allison. "Eng 421: Electrical Design 2." Murdoch

University, 2013. [Accessed 23/08/2013] [11]Australia, Standards. "As 1768: Lightning Protection." Standards Australia, GPO Box

476, Sydney. NSW 2001 and Standards New Zealand, Priate Bag 2439, Wellington 6020, 2007. [Accessed 12/12/2013]

[12] Council, Clean Energy. "Approved Inverter List." 2013. [Accessed 15/08/2013] [13] Council, Clean Energy. "Approved Module List" 2013. [Accessed 15/08/2013] [14] Overton, Rodney. "Feasibility Studies Made Simple." Martin Books,

http://www.murdoch.eblib.com.au/patron/FullRecord.aspx?p=306614&echo=1&userid=21159c59ed13b928d835b6d64cd2b2a1&tstamp=1386296168&id=449c78797688a6ee524dff95d4cd6533. [Accessed 01/01/2014]

[15] "Engineering Feasibility Studies." HRL technology,

http://www.hrlt.com.au/engineering-feasibility-studies/w4/i1039651/. [Accessed 01/01/2014]

http://ret.cleanenergyregulator.gov.au/Certificates/Large-scale-Generation-Certificates/about-lgcs

http://ret.cleanenergyregulator.gov.au/Certificates/Large-scale-Generation-Certificates/about-lgcs

http://www.murdoch.eblib.com.au/patron/FullRecord.aspx?p=306614&echo=1&userid=21159c59ed13b928d835b6d64cd2b2a1&tstamp=1386296168&id=449c78797688a6ee524dff95d4cd6533.



http://www.hrlt.com.au/engineering-feasibility-studies/w4/i1039651/


[16] "Balance Services Group." http://www.balanceservicesgroup.com.au/?page_id=1623. [Accessed 14/01/2014]

[17] Krishnan, G., and D. N. Gaonkar. "Control of Grid Connected and Islanding

Operations of Distributed Generation Systems with Seamless Transfer between Modes." Paper presented at the Control Applications (CCA), 2013 IEEE International Conference on, 28-30 Aug. 2013 2013. [Accessed 16/01/2014]

[18] E.C Okogbue, J.A. Adedokun, B Holmgren. "Hourly and Daily Clearness Index and

Diffuse Fraction at a Tropical Station, Ile-Lfe, Nigeria." INTERNATIONAL JOURNAL OF CLIMATOLOGY (2008). [Accessed 03/01/2014]

[19] M Calais, A Ruscoe, M Dymond. "Transformerless Pv Inverter Issues Revisited - Are

Australian Standards Adeqate?" In 47th ANZSES Annual Conference. Townville, Queensland, Australia, 2009. [Accessed 10/01/2014]

[20] Dirk C, J, and S R. Kurtz. "Photovoltaic Degradation Rates - an Analytical Review."

Progress in Photovoltaics, no. Research and Applications (2012). [Accessed 11/01/2014]

[21] . Synergy- ONLINE http://www.synergy.net.au/at_home/how_can_i_read_my_meter.xhtml. [Accessed

12/01/2014] [22] Balato, M., and M. Vitelli. "A Hybrid Mppt Technique Based on the Fast Estimate of

the Maximum Power Voltages in Pv Applications." Paper presented at the Ecological Vehicles and Renewable Energies (EVER), 2013 8th International Conference and Exhibition on, 27-30 March 2013 2013. [Accessed 23/12/2013]

[23] A, Ricciardi. "Improved Maximum Power Point Tracking with Partially Shaded

Photovoltaic System." Curtin University, 2012. [Accessed 13/01/2014] [24]"Degrees of Protection Provided by Enclosures (Ip Code)." In AS 60529 - 2004.

Standards Australia International: Standards Australia International Ltd, 2004. [Accessed 23/08/2013]

[25] Abidin, H. Z., and R. Ibrahim. "Thunderstorm Day and Ground Flash Density in

Malaysia." Paper presented at the Power Engineering Conference, 2003. PECon 2003. Proceedings. National, 15-16 Dec. 2003 2003. [Accessed 14/01/2014]

[26] Australia, Standards. "As 5033 Installation and Safety Requirements for

Photovoltaic (Pv) Arrays." 2012. [Accessed 17/01/2014] [27] SÖHNE, DEHN +. "Lighitning Protection Guide Revised 2nd Edition." DEHN + SÖHNE,

2012. [Accessed 20/01/2014] [28] "Connecting Transmission Loads and Large Generators to the Western Power

Network." http://www.westernpower.com.au/documents/business/generators/WP_connection_process_maps_CAG.pdf. [Accessed 28/12/2013]

http://www.balanceservicesgroup.com.au/?page_id=1623.

http://www.synergy.net.au/at_home/how_can_i_read_my_meter.xhtml.

http://www.westernpower.com.au/documents/business/generators/WP_connection_process_maps_CAG.pdf.

http://www.westernpower.com.au/documents/business/generators/WP_connection_process_maps_CAG.pdf.


[29] Australia, Standards. "As 5033 Installation and Safety Requirements for Photovoltaic (Pv) Arrays." 2012. [Accessed 20/01/2014]

[30] Australia, SMA. "Sunny Island 5048u Product Training." edited by SMA Australia.

SMA. [Accessed 23/01/2014] [31] “Australian Government Clean Energy Regulator”-Online

https://www.rec-registry.gov.au/home.shtml [Accessed 2/02/2014]

[32] "About Homer Energy." http://homerenergy.com/index.html.[Accessed 11/02/2014]

[33] "About Sketch Up." http://www.sketchup.com/about/sketchup-story. [Accessed 11/02/2014]

[34] "Small Generation Unit Stc Calculator." Australian Government, https://www.rec-registry.gov.au/sguCalculatorInit.shtml. [Accessed 11/02/2014]

[35] "Green Energy Trading." http://greenenergytrading.com.au/.[Accessed 11/02/2014]

[36] Power, Western. "Access Arrangement Information." In Standard Access Contract Demonstration of Code Compliance: Western Power. [Accessed 11/02/2014]

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http://greenenergytrading.com.au/


16 Appendices

16.1 A1: Synergy bi-directional metering generation

16.2 A2 : Western Power application

16.3 A3: Synergy Approval

16.4 A4: Western Power Approval

16.5 A5: SMA SB2500-TL data sheet

16.6 A6: STP 5000TL-20 data sheet

16.7 A7: Fronius IG15 data sheet

16.8 A8: Kyocera KD315GX-LPB datasheet

16.9 A9: Sun Power SPR-200-BLK datasheet

16.10 A10: Single Line Diagram of 9.04kW system

16.11 A11: BOS component list

16.12 A12: Approved locations for PV

16.13 A13: SPR-200-BLK Test Results

16.14 A14: BE Commissioning Instructions and Test Sheets

16.15 A15: Fencing Option A

16.16 A16: Fencing Option B

16.17 A17: Fencing Option C

16.18 A18: Email Correspondence With Frontier rack

16.19 A19: Email Correspondence with Frontier Rack

16.20 A20: Low Level Gantt Chart for Minor project

16.21 A21: Lightning Risk Assessment

16.22 A22: Cable Loss Calculations (

16.23 A23: Cable Loss calculations ( )

16.24 A24: Sunny island 5048 datasheet

16.25 A25: Project plan (24/01/2014)

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