Biomass District Heating New Build & Retrofit

District Heating SeminarDorset County Council 13th Oct. 2009

chris.miles@econergy.ltd.uk

Biomass heat market Heat is responsible for 47% of UK’s C02 emissions

• Potential UK biomass heat market (RES Strategy):

– Space/water heat in buildings– Process Heating– Up to 8% of heat (38Twh) by

2020– Renewable Heat Incentive

from April 2011– #2 potential after wind

• Market becoming mainstream– Specialist suppliers– Traditional boiler suppliers– Utilities

• Substantial fuel sources– UK forestry, waste wood– Energy crops from UK

agriculture– Substantial pellet import

potential• Mature technology

Biomass Heating: Carbon Neutral Cycle• As trees grow they absorb CO2• During photosynthesis the tree stores

carbon in their woody tissues & O2 is released into the atmosphere

• At harvest wood fuel is transported to the heat or power generating plant

• As wood is burnt the carbon stored combines with O2 to form the same amount of CO2

Econergy Ltd: The Company

• UK’s premier biomass heating supplier

– Founded 1999– > 350 projects sold to date– Approx 70 schools & colleges– 13% of UK installed base– 10KW to 2MW– 2009 investment by British Gas

• Biomass energy– turnkey solution design & supply– district heating– biomass heat supply - sell metered

heat• Leading supplier to public sector

– council offices, schools, social housing, universities, leisure centres, hospitals, care homes, education centres etc.

• Delivering direct & via network of partners

Retrofit energy centre: 300 flats, 6 blocks Sheffield Homes

New Biomass energy centre: 97 houses

Econergy Customers include:Bold: district heating included in at least one of the sites

ContractorsNG BaileySir Robert McAlpineLorne StewartDodd GroupKier GroupSkanskaBovisBalfour BeattyCrown HouseMitieHaydon YoungCrest NicolsonBriggs & ForrestorWaringsT ClarkeInterserveInviron

National Star CollegeSouth Shropshire HousingBromford CorinthiaHousingBirtley House Care HomeBowood Estate & Golf ClubMarks & SpencerBradford UniversityUniversity of CambridgeBerkshire College of AgricultureTelford & Wrekin CouncilMaidstone CouncilRoyal Victoria HospitalIslington Borough CouncilFinchley Borough CouncilCo-operative GroupWessex WaterRSPB

End CustomersNational Trust (x10)Barnsley MBC (x8)Bristol Council (x2 + 4)Forestry Commission (x6)Sheffield Homes (x4)S. Lanarkshire Council (x4)Suffolk Council (x4)Earl of Ronaldshay (x4)Worcestershire Council (x4)Bradford Council (x3)Duchy of Cornwall (x3)Doncaster Council (x2)Kent County Council (x2)Kevin McCloudForeign & Commonwealth OfficeRoyal Cornwall NHS Trust

Biomass heating system- design considerations

• What is the customer’s objective(s) ?– CO2 reduction, fuel cost reduction, meet building/planning regs.

• Peak heat loss, profile and physical distribution of buildings• Wood fuel selection & logistics

– Fuel type, availability & price v. boiler specification– Wood fuel delivery vehicle v. fuel store design

• Space & access for biomass boiler plant– Fuel delivery, receipt, storage options & delivery vehicle needs– New build v. Retrofit– Capital cost v. fuel & operating supply cost

• Planning issues (visual, air quality, noise, traffic….)• Hydraulics & controls philosophy

Which fuel type ?

Wood chip Wood pellet LogsHeat cost: 1.5 - 3p/KWh10KW to 10MWLow energy density (600KWh/m3)Automatic feed for 24x7 hour operationMedium /large scale operation is most economic

Heat cost: 3 - 4.5p/KWh10KW to 1000KWHigh energy density (3450KWh/m3)Can transport long distancesFuel “flows”Fuel delivered by blower –fuel store generally simpler & cheaper

Heat cost: 1 - 4p/KWh15 to 70KWEasy to handleKnown & existing supply chainCan produce from small scale wood land

ConsiderationsNeed local supplierQuality can be variableFuel reception design is key & can be expensiveFuel does not flow & is difficult to handle

ConsiderationsPellet quality is criticalCostNeed large scale production to keep costs downUnlikely to be local

ConsiderationsNeed to load manually at least once per dayOnly suitable for small scale

Wood Chip Supply Chain - local jobs & fuel security

via chipping & storage to

low carbon heat

from tree surgeonor forest

Wood fuel delivery:Capital cost v. fuel supply cost

1) Underground Bunker (Chip)2) Blown delivery (Pellet/Chip) 3) Scissor lift trailer (Chip)

4) Hook lift bin (Chip)

(1) New Development: Typical District Heating Objectives

• Reduce heat demand• Affordable & reliable heat• Reduce CO2 emissions• Meeting Planning, Building Regulations, Code for

Sustainable Homes, BREEAM etc.• Meeting emissions requirements (PM10s & NOX)• Maximise available space within dwellings• Ease of maintenance (minimise work in home)• Safety (e.g. gas leaks, CO poisoning), comfort and

convenience for customers

A typical boiler house

Carwood Close community heating energy centre serving 97 properties, including 320 kW biomass boiler and 2 standby gas boilers with excavated bunker for tipped deliveries. Econergy turnkey installation.

Underground heat mains

Single and twin plastic underground heat main

A fusion welded tee joint being made

Very low heat losses – circa 10 Watts per meter

Long life maintenance free buried installation

Domestic heat interface units

Typical Heat Interface Units; direct heating with hot water heat exchanger (left), complete twin heat exchanger for heating and instantaneous hot water (centre), typical casing (right).

New Build District Heating (2008):Rocks Green, Ludlow

• SSHA Rocks Green - 91 houses• Two 150kW fully automatic KWB

biomass boilers• Twin 200kW standby oil boiler and

tank• 1,200 metres of twin underground

pipe• Interface units incorporate a heat

meter, heat exchanger and pressure balancing valves

• 615,000 kWh per annum planned heat delivered

• Just over 200 tonnes of wood fuel per annum

• Saving 120 tonnes of CO2 p.a. based on gas

Rock’s Green

(2) Biomass District Heating– Retrofit Plant Room

• Sheffield Road Flats, Barnsley: Community district heating for 3 tower blocks (147 units)

• 470KW (150KW + 320KW)– Commissioned 1Q2005– High load factor for wood fuel

boilers, gas back-up– Serving 3 plant rooms

• Energy services contract– Econergy in 5th year– 1.4million KWhs/annum of

biomass heat delivered in 2007 (virtually no gas used)

– 500 tonnes of wood chip– 240 tonnes of CO2 saved pa

• Substantial cost reduction via demand management (pre-payment heat meters in flats)

(3) Existing buildings, new plant room & underground heating mains

National Star College, Nr Cheltenham – Special Needs College– New build energy centre for mission

critical heat 24 x 7 x 365– Supplying 14 buildings

Turnkey M&E design & supply– 500 + 320kW wood chip boilers– Underground 4m x 7m x 3m scaper

floor fuel bunker– 2 x 400kW back-up oil boilers – All plant room equipment– 1.6 km underground htg main– 14 local interfaces replacing 20 oil

boilers (13 direct, 1 via heat exchanger)

– 3 x 5,000 litre buffer tanks (central heat stores)

– Return 65 DegC; Flow 70 to 85 DegC

Heat Mains Network.

Energy Centre

Local Commercial Interfaces

The largest interface on the campus is within the Manor. The existing boilers provided heat to the Manor, Wilson Court residential block and Creative Arts Building.Now 315kW heat exchanger services the duty requirements.

Heat Exchanger connects to the original system on the existing flanges

Local Domestic InterfaceSchematic Layout

Hydraulic Scraper Floor Fuel System.

Hydraulic Scraper Floor Fuel System.

Operation• Fuel is delivered by a large tipping trailer into the excavated

bunker of 120m³ total volume (estimated 80m³ working volume)

• Fuel is automatically extracted and transferred to the ground level boilers by a hydraulic scraper floor system and fuel transfer augers.

• Expected fuel delivery frequency could be up to 3 deliveries of 50m³ per week in cold weather, less in milder conditions.

• Annually the boiler would use approximately 1,200 tonnes of wood chip at 30% moisture content to supply an estimated 90% of the projected year-round heating requirement.

Support for Biomass Heat

• 15% renewable heat by 2020, 8% biomass:

– “To meet the 2020 targets for renewable energy, the UK needs to increase very substantially the amount of renewable heat generated, and biomass heat is one of the key technologies..”

Lord Hunt, DECC, April 2009• Current support mechanisms:

– Planning Policy– Code for Sustainable Housing– Grants: BCGS, LCBP– ECA’s– Energy Efficiency Funding, CERT

• Renewable Heat Incentive (Apr 2011)– 1 to 4 p/kWh (probable range – tbc)– Supporting installations from July 2009– Consultation with preliminary values in

Dec 2009

National Star: 820 kW District Heat

Potential RHI economics:e.g. Care Home, Surrey

• 25,000 ft care home– c.700,000 kWhs of heat

pa– peak load: 200-250 kW

• 150kW biomass boiler

– sized for c.85% of demand

– peak load & stand-by gas

• Capital: c. £120,000 excl. grant

• c.200 tonnes wood chip pa

• if RHI were 1.5 p/KWh ……

Typical benefit: Biomass heating v. gasPrevious gas cost £22,500 at 3p/KWh GCVBiomass cost £18,000 at £90/tonneRHI (conservative) £9,000 at 1.5p/KWhBenefit pa £13,500Simple payback 8.9 years+ CO2 saved pa 127 tonnes CO2Typical benefit: Biomass heating v. oilPrevious oil cost £28,500 at 37p/litreBiomass cost £18,000 at £90/tonneRHI (conservative) £9,000 at 1.5p/KWhBenefit pa £19,500Simple payback 6.2 years+ CO2 saved pa 180 tonnes CO2

Indicative numbers only for different fuel types & possible Renewable Heat Incentive

Key Success Factors

• Must agree detailed requirements, scope and specification (lots of iteration)– Get design done before breaking ground

• Attention to design detail on all aspects• Ensure adequate program length to minimise costs• Substantial co-ordination with civils

– Econergy often write outline spec for builders works – Heat mains, plant room, fuel bunker, all local connections

• Budget & allow enough time for commissioning– e.g. plan for unexpected problems connecting to old local

systems

Further Information & contacts

• More information in Consultants Pack• Enquiry form on web-site www.econergy.ltd.uk• Call Dawn Riggett or myself 0870 0545554• sales@econergy.ltd.uk