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Renewable Firewood Stoves; a community approach to widespread installation and fuelling suitable for future inclusion in the RHI. Jeremy Thorp Cwm Harry 28 th March 2012. Project Funding and timescales.
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Renewable Firewood Stoves; a community approach to widespread installation and fuelling suitable for future inclusion in the RHI Jeremy Thorp Cwm Harry 28th March 2012
Project Funding and timescales • This project has been funded through the LEAF project (Local Energy Assessment Fund) set up by DECC and administered through the Energy Saving Trust. • Funding was confirmed on 7th February, and the project had to be complete by the end of the Financial year (31st March)
Why? • Non-domestic Renewable Heating Incentive (RHI) offers 7.6p/kWh to users of log batch boilers, wood pellet boilers and wood chip boilers but not log stoves. • Domestic RHI (phase 2) due to be introduced Summer 2013 • Phase 2 expected to exclude wood stoves same as phase 1
Why are log stoves excluded? • Difficult to measure heat output • Difficult to establish sustainability of fuel supply
1. Difficult to measure heat output • RHI is based on total heat delivered. For pellet stoves, chip stoves etc, delivered heat would be measured using heat meter in hot water pipes • Log stoves deliver most heat as radiant – more difficult to measure • Deemed heat – difficult as log stoves often used as supplementary heating
2. Difficult to establish sustainability of fuel supply • DECC argue that you cannot ensure that users are not burning coal (or other non-sustainable fuel) on a log stove
Solutions:1. Measurement of heat output • Is direct measurement possible? • Can we produce a look-up table to convert between something measurable (e.g. Flue surface temperature) and heat output? • Experiments have been carried out to investigate this possibility (see separate presentation)
Solutions:1. Measurement of heat output • Are there alternative ways of measuring heat output? • Can we deduce from fuel input an assumption on efficiency of burn? • How could this be set up in an auditable way?
Measuring fuel use • Set up company (ESCo) which can take out a long term contract with the client • Volume of wood delivered would be auditable • Demonstrates proof also of the sustainability of supply (as long as the ESCo can demonstrate it purchases from sustainable sources)
Measuring fuel use • Could either measure at household level or at ESCo level • At household level – need accurate data on weight, species, water content, of each batch delivered • At ESCo level, only need to prove gross weight, species, etc for supplies coming into the ESCo • ESCo could receive the RHI on behalf of households, and distribute to them
Measuring fuel input • The household would have to have a new efficient stove installed by the ESCo to qualify • The ESCo would install the stove, provide training on use, maintain (sweep chimney) once a year and contract to provide wood for 10 year period
What is the price of log fuel? • What is the price of heat from logs (compared to oil and gas) • Does it need a subsidy from RHI, and if so, how much? • What is the price elasticity? • What is the aesthetic value of a log fire? • What is the “nuisance” cost of lighting it?
What price are logs? • “Farm gate” price of 5p – 8p/kWh (based on 1m3 bag of hardwood at £37.50 and 1m3 softwood at £27.50) • (Assumes overall efficiency of stove of 50%) • Need approx 7.6p/kWh (to achieve same income per acre as rent from grass keep)
Public acceptance • Set up user focus groups • Address questions such as: • Convenience compared to oil/gas • Reliability of fuel supplies (wood and oil/gas) • Storage of wood fuel • Question? How do we attribute a price to side issues such as the aesthetic attraction, the inconvenience factor, the carbon reduction effect?
Evidence from focus groups • The majority want to use wood for the following reasons: • cost, personal satisfaction, environmental benefits • Of particular interest is the agreement that they all felt a sense of satisfaction / a relationship with their stove and wood fuel and enjoyed the process • Questions to address in the second group: • Options for “firewood club”, (ESCO / Co-op...) • Discuss options for storage at scale • Cost of keeping warm • Barriers to change • Skills e.g. lighting fires • Rented accommodation • Alternative uses of the heat • Expert advice on installation, fuel and maintenance
Focus group feedback • People want to be actively engaged, not at a distance as they are with oil and gas where delivery is in someone else's hands leaving the home owner out of control • Importance of price for wood fuel, • Awareness of how to use wood heating most effectively, etc
Supply versus demand • What is the potential volume of wood fuel available for household use in the UK? • How many households would a log stove be appropriate for?
What is the potential volume of wood fuel available for household use in the UK? • How much fuel wood could be obtained from existing sustainable sources? • Address issues of: • Alternative uses of timber (saw-wood, mdf production) • Need to maximise value obtained from woodland • Use of the waste stream (equal in size to home grown timber) • Large quantities currently used for dual-firing of coal fired power station
What is the potential volume of wood fuel available for household use in the UK? • UK total woodland area 3,078,000 hectares • (870,000 managed by Forestry Commission) • Total harvest 9.5 million green tonnes coniferous, 0.5 million tonnes broadleaf timber • = 3.25 green tonnes /ha/yr • State forest in Wales 7.5 green tonnes /ha/yr • Hence theoretical additional 4.25 green tonnes/ha/yr from 3,002,000 hectares = 12 million green tonnes per year = 19million Mwh = 0.6 million homes
Supply • For Powys 75,083 hectares of woodland • Survey indicates woodlands are adequately but not heavily stocked • Suggest 4.2 m3/yr could be harvested, of which, 40% is firewood. • Suggest county yield of 80,000 m3 hardwood and 400,000 m3 softwood suitable for firewood
How many households would a log stove be appropriate for? • Off the mains gas grid • Demographics – (<70 yrs, disabilities etc) • Logistics (can a flue be installed, is there room for a stove, storage space for fuel, not high-rise flats etc) • What is the typical carbon saving per household?
Carbon saving from households • Estimate of 21% of households not on mains gas grid could benefit from installation of a log stove • Estimate 5m3 of dry logs used in average dwelling • Estimate 2.5 tonnes CO2 saving per household • National potential – 2 million tonnes carbon saving per annum
6 models No RHI With RHI
Contracts Model maps Goods Money Social Enterprise Government Heat user Fuel supplier
Green deal agreement Contracts 1a: No RHI, Green Deal funding for stove installation Goods Money Payments based on fuel usage, passed on Social Enterprise Government Green deal agreement Supply of stove Payments based On fuel usage Green deal agreement Fuel supply Heat user Fuel supplier Payments for fuel + Green Deal charge
Contracts 1b: no RHI, private loan fund for stove installation Goods Money Social Enterprise Regular loan repayments Supply of stove Loan agreement Initial loan Fuel supply Heat user Fuel supplier Payments for fuel
Contracts 1c: no RHI, fuel supply only Goods Money Social Enterprise Payments for fuel Payments for fuel Fuel supply contract Fuel supply Heat user Fuel supplier
Contracts 2a : RHI certification obtained on stoves Goods Money RHI registration RHI Payments based on heat usage Social Enterprise Government Lease Purchase of stove Stove supplier RHI accreditation Installation of stove Fuel supply Heat user Fuel supplier Purchase of fuel
Contracts 2b : RHI certified log fuel Goods Money RHI registration RHI Payments based on fuel usage Social Enterprise Government Purchase of fuel Fuel supply contract RHI accreditation Possible RHI accreditation Purchase of stove Fuel supply Fuel supplier Heat user Stove supplier Installation of stove
Contracts 2c : RHI certified log fuel ESCo model Goods Money RHI registration RHI Payments based on heat usage Social Enterprise Government Payments based On heat usage ESCo contract Purchase of stove Purchase of fuel Stove supplier Installation of stove Fuel supply Heat user Fuel supplier
For each model: Is it viable - worth pursuing? What are the barriers/hurdles to pursuing this? No RHI With RHI