Microrenewables Kevin Lindegaard Renewable Energy Development Officer Dorset County Council 24 April 2007

Microrenewables Heating Solar water heating Heat pumps Pellet and log boilers Electricity Photovoltaics (PV) Small scale wind turbines Micro hydro

Energy basics Unit of power is the Watt (W) 1 kW = 1000 W To convert power to energy multiply by number of hours Using a 100 watt bulb for 10 hours = 1000 Watt hours = 1kWh

Domestic energy use Electricity = 2, ,000 kWh Gas = 8, ,000 kWh Oil = 4,000 litres 1 kWh of electricity costs 10p 1 kWh of gas = 2.5p 1 kWh of oil = 4p

Solar Water Heating Flat plate Evacuated tube Unglazed Increasing efficiency/cost

Domestic systems 50% of hot water needs overall % of needs in summer 3-4m 2 array Roof should face between SE and SW and avoid shading 35-45° pitched roof or mounted on A- frames Need to have new hot water tank kWh/year years useful life

What does it cost? TechnologyInstallation2 m23 m24 m26 m2 Flat plate Closed Installer/£3,150£4,200£5,000 DIY//£1,500£2,500 Open (direct) Installer/£3,400// DIY/£2,500 //// Evacuated tube Installer£4,200£5,500// DIY£2,115/ DIY = 17.5% and no grant Installer = 5% and £400 grant

What is the pay back? Savings are best in off-gas areas Long paybacks but fossil fuel prices increasing Pay back* DIY9 years Flat plate17 years Evacuated tube 31 years * Based on replacing on peak electricity saving £162 per annum

Opportunities Domestic hot water (not heating) New build eco homes B&B, hotels Swimming pools Campsites

Heat Pumps Ground source Air source Water source Harness solar energy stored in ground, air or water sources Uses electricity to drive compressor to raise heat to useful temperature 1 kWh of electricity in provides about 3-4kWh of useful heating

Options Provides space &/or DHW, (potential also for summer cooling) Best niche is new build, because: - Well insulated - Combine with other works - Best with under floor heating Limited visual impact

What does it cost? Cost including distribution system Grant 8 kW Ground source HP £10, ,000£ kW Air source HP £6,000£0 8 kW Water Source HP £6,500£0 Pay back ~15-20 years

Biomass heating Rika Thermia Room heater Boilers Stove with back boiler Extraflame Ökofen KWB Herz Kalorina

Heating with wood pellets Room heaters or back boilers 3 times greater density than wood chip Flowable Cheaper to transport than other biomass Compact and clean handling (dust free) for domestic market Automatic ignition and feed Cope with variable load demands and can be operated on a timer Integral hopper Very efficient with low emissions

Showstoppers? Need space for fuel storage Good access for deliveries Bulk buying is best - bagged pellets are 2x the price of bulk deliveries More hands on Ash removal

Vigas Froling Pyromat Log boilers

Vigas 25 boiler Very efficient and as sensitive and controllable as an oil boiler 120-litre log magazine - stores enough logs for about 14 hours burning 4 kg/hour and will use about 12 tonnes or 25 m 3 of cut logs per year Hands on – manual filling £4,500 (£5,300 with 1000 litre accumulator tank)

25 year fuel costs Fuel typeUnit cost25 year cost* Heating oil40p litre£40,714 Gas2.5p/kWh£18,750 Wood pellet£160 tonne£24,000 Grain£85 tonne£15,300 Logs£80 tonne£14,100 * Based on annual fuel usage of 30,000 kWh

How much do they cost ? Fuel typeBoiler make and model Approx cost inc installation Wood pelletOkofen 25 kW£15,000 GrainKalorina 25 kW£7,000 LogsVigas 25 kW£4,500 £1500 grant available Pay back 5-15 years versus oil

Photovoltaics (PV) Polycrystalline SiThin Film Increasing efficiency/cost Monocrystalline Si

Photovoltaics (PV) Use semi-conductor cells to convert light into electricity Inverter turns direct current (DC) into alternating current (AC) which can be used or sold to the grid Low maintenance, with 25 year lifespan Can be roof mounted (bolt-on) or roof integrated Work best in direct sunlight - need to avoid shading Remote applications

PV Domestic system 1.5-2kWp modules area of 12-40m kWh/year £12-14,000 30% grant available Lifestyle changes 800 kWh per annum would save about £96 per annum against buying electricity from the grid – no pay back

Roof mounted wind Need to be on high buildings Designed to work in turbulent conditions Limited planning issues in non listed buildings Wind speeds avg 3.5 m/s 1.5 kW – supposedly produces 1000 kWh p/a Windsave 1 kW Swift 1.5 kW

What does it cost? Rotor (M) Rated power Power output p.a. at Total cost inc. installation LCBP Grant 5.0 m/s 5.5 m/s Windsave W 883 kWh 1,000 kWh £1,600£480 Swift W 1,031 kWh 1,307 kWh £4,500- £6500 £1,350 Pay back ?

Stand alone wind turbines Iskra 5 kW Proven kW

Costs, outputs and sizes Proven 2.5 kW Proven 6 kW Iskra 5 kW Price inc installation£14,000£21,000£18,000 Grant£2,500£5,000 Tower height (m)6.5 or 119 or 1512 or 15 Blade diameter (m) Output (kWh/yr)3,500 at 5 ms 10,000 at 5 ms 5,000 at 4 ms Pay back ~11 years

Micro Hydro Run of river schemes e.g. historic water mills or hilly areas with spring fed streams Generally < 100 kW Can be used in rivers with as little as 1m heads Most cost effective of all renewable resources where suitable sites exist

How it works

Micro Hydro – pros & cons Weirs and leats are in many cases still usable Zero annual fuel costs & low running costs Long lifetime - generator (15 yrs), turbine (25yrs) High reliability and availability High load factor (50-70%) Reasonable pay back period (<10 years) River flow rates vary so low output in summer Grid connections can be expensive Low electricity prices paid to small producers Planning

How much does it cost? Installation costs £2000/kW A 10 kW system would cost £20,000 LCBP grant - max of £5000 Payback = 9.5 years

More information Low Carbon Buildings Programme Energy Saving Trust case studies Dorset Energy Group Renewable Energy Association

More information Solar Trade Association Ground Source Heat Pump Association British Wind Energy Association British Hydropower Association Biomass Energy Centre Woodfuel South West Advice Service Woodfuel suppliers