Woodfuel Heating Case Studies

Alison Wilshaw TV Energy

BIRTLEY HOUSE • Family run residential care

home, nr Guildford • Care home -> high heat

load

• Heated with biomass since 2008

PROJECT DETAILS Birtley House

• Old, inefficient buildings • High energy consumption (gas and

electricity) • Estate has its own woodland,

therefore large amount of wood thinnings available

• Woodchip boiler was installed to provide heating fuelled by the surplus wood

PROJECT DETAILS Birtley House

• KWB TDS Powerfire 150 kW woodchip boiler

• Sized to provide 80% annual energy requirements

• Boiler and buffer tank housed in an existing outside store room

• Underground chip bunker next to boiler house

• Chip store size: 4m x 4m x 2.5m • Woodchip tipped through central

hatch into bunker

PROJECT ECONOMICS Birtley House

• Total project cost: £121,500

• Boiler, accumulator and fuel feed mechanism: £40,000

• Civil works (fuel store and access road): £36,500

• Annual energy generation: 600,000kWh

• Fuel savings: ~ £14,000 pa, assuming use of estate’s own woodchip

• Annual O&M cost: Approx. £3,000

• Grant received: £18,500 from the Bioenergy Capital Grant Scheme

• RHI payments: not eligible

• Payback period: 9 years

• IRR: 12%

CURRIDGE PRIMARY SCHOOL • Small, village primary school

(100 pupils) • Main building over 100 yrs

old, plus some temporary classrooms

• Existing oil fired boilers very unreliable

• Decision to look at alternative fuels due to escalating oil price

• Woodchip boiler installed in September 2007

PROJECT DETAILS Curridge Primary School

• Herz woodchip boiler 50 kW • 2000 litre buffer tank • Above ground chip store, next to the

boiler house • 10m3 fuel store capacity (2.5 tonnes

woodchip @30% MC)

PROJECT ECONOMICS Curridge Primary School

• Total project cost: £68,182

• Biomass boiler and associated equipment: £23,228

• Chip store cost: £2,488

• Civil works (building mods, DH): £20,198

• Annual O&M cost: average £885

• Annual energy generation: 56,200kWh

• Fuel savings: ~ £1,340 pa

• Grant received: £40,000

• RHI payments: not eligible

• Payback period: 12 years

• Internal Rate of Return: 7%

MANOR FARM

• 350 acre farm in Hampstead Norreys, near Newbury

• Farmyard regeneration providing accommodation for local businesses and self-catering holiday cottages

• Biomass boiler and district heating installed in December 2010

PROJECT ECONOMICS Manor Farm

• 60kW Therminator II woodchip boiler • 3000 litre accumulator tank • District heating network supplies heat

to holiday apartments, community shop and hair salon

• 30m3 above ground chip store

PROJECT ECONOMICS Manor Farm

• Total project cost: £107,000

• Boiler, accumulator, civil works: £72,000

• Chip store: £35,000

• Underground pipework: £50/metre

• Annual energy generation: 105,100 kWh

• Fuel savings: approximately £3,500 per annum (compared to oil)

• Annual O&M cost: Around two hours per week operating costs.

Annual boiler servicing is around £750

• Grant: £62,500 (Leader / FWAG)

• RHI payments: ineligible

• Payback period: 8 years

• IRR: 14%

HUGHENDEN MANOR • Oil boilers needed replacing • Requirement to reduce fossil

fuel usage and associated CO2 emissions

• Project acts as exemplar to other similar properties

• Grade I listed building

• Owned by the National Trust

• Set in the Chilterns AONB

PROJECT DETAILS Hughenden Manor

• Fröling Turbomat 220kW, installed November 2010

• 4,500 litre accumulator tank • 35m3 chip store cut into bank adjacent to

boiler room, allowing easy delivery from higher ground

PROJECT ECONOMICS Hughenden Manor

• Total project cost: £298,700

• Chip store cost: £26,000

• Annual energy generation:

200MWh

• Fuel savings: ~£6,500 pa.

Woodchip is supplied from the

estate’s own woodlands

• Annual O&M cost: ~£3,400

• RHI payments: Expected to be

10,200 pa

• Payback period: 15 years

• IRR: 4%

HAMPTON ESTATE • Grade II listed Georgian House, with

2250 acres of land used for farming and forestry

• Two farms on the estate are heated with biomass boilers using woodchip from the estate

PROJECT DETAILS Binton Farm, Hampton Estate

• Traditional agricultural estate within

the Surrey Hills AONB • Woodchip being produced on the

estate since 2005 • Residential and commercial property

lettings • In August 2011, a biomass district

heating system was installed to provide heating and hot water to five residential properties

PROJECT DETAILS Binton Farm, Hampton Estate

• ‘Energy Centre’ located in an

existing barn • d’Alessandro 60 kW woodchip

boiler • 2,500 litre accumulator tank • Above ground chip store

adjacent to boiler • 5m3 storage capacity • Truck tips directly into fuel store • Agitator and auger move chip

into boiler

PROJECT ECONOMICS Binton Farm, Hampton Estate

• Total Project Cost: £100,000

• Chip store cost: £800 (second hand)

• District heating network: £25,000 for 350m

• Annual energy generation: 78,500 kWh

• Fuel savings: £2850 per year over cost of oil

• Annual O&M cost: carried out by staff

• RHI payments: Expected to be around

£6,500 pa

• Payback period: c. 9 years

• Internal Rate of Return: 11%

SURREY SPORTS PARK

• Sports Centre owned by the University of Surrey • Used by students, local residents and high

performance athletes • Large, consistent heat load due to 50m swimming

pool • Biomass system designed to supply a proportion of

the base load

PROJECT DETAILS Surrey Sports Park

• Gilles HPKI-K 300kW woodchip boiler installed in January 2010

• Chip store is an underground bunker, designed to allow a tipper trailer to tip directly into the store

• Chip store has fuel capacity of 50m3 and is adjacent to plant room

PROJECT ECONOMICS Surrey Sports Park

• Total project cost: £224,350

• Chip store cost: £39,335

• Annual energy generation: ~1,500MWh

• Fuel savings: none at present, gas price at 2p/kWh

• Annual O&M cost: Service contract of £7,500

• RHI payments: Expect to receive around £40,000 pa

• Payback period: 9 years

• IRR: 13%

WAITROSE, BRACKNELL • National supermarket

chain, looking for ways in which to reduce its carbon footprint

• Following discussions with TV Energy, decided to commit to the installation of biomass Combined Heat and Power (CHP) • CHP systems installed on the Isle of Wight and in Bracknell

• Designed to supply 68% of electricity and 84% of heating at the Bracknell site

PROJECT DETAILS Waitrose, Bracknell

• Four modular CHP units, manufactured by Stirling DK • ‘Trigeneration’ – generates power for heating, cooling and

electricity • Each unit rated at 35kWe and 140kWth

• Woodchips stored below ground in a 135m capacity chip store

• Woodchip is moved into the gasifier using a system of agitators, augers and bucket elevators

PROJECT ECONOMICS Waitrose, Bracknell

• Total project cost: £3,000,000

• Annual energy generation: 980MWhe

and 3,920MWhth

• Fuel savings:

• Annual O&M cost: £100,000 per

annum (complete system overhaul

twice a year)

• RHI payments: around £95,000 pa

• Payback period: 12 years

PROJECT ECONOMICS Summary

Project Rating (kW)

Installed Cost (£/kW)

Payback (years)

IRR (%)

Birtley House

150 £813 9 12%

Curridge Primary

50 £1,364 12 7%

Manor Farm

60 £1,783 8 14%

Hughenden Manor

220 £1,358 15 4%

Hampton Estate

60 £1,667 9 11%

Surrey Sports Park

300 £748 9 13%