Presentation on theme: "SOLAR for HOT WATER and HEATING Here Comes the Sun - London Solar: heat with care."— Presentation transcript:
SOLAR for HOT WATER and HEATING Here Comes the Sun - London Solar: heat with care
WHAT SOLAR HEATING HAS TO OFFER… A MATURE & WELL ESTABLISHED TECHNOLOGY VERY WIDESPREAD APPLICATION SOLAR HEATING is a VERY LOW CO2 EMITTING TECHNOLOGY EFFICIENT CONVERSION of LIGHT to HEAT VERY GOOD for HOT WATER and CAN WORK VERY WELL for HEAT COMBINES WELL with CONVENTIONAL HEATING SYSTEMS & OTHER RENEWABLE TECHNOLOGIES
HERE COMES THE SUN SOLAR for HOT WATER and HEATING: A MATURE & WELL ESTABLISHED TECHNOLOGY solar water heating is ‘OLD TECH’… In California, USA “CLIMAX” Solar Water Heaters were sold & installed from 1890’s. Clear standards for design & manufacturing: EN 12975 test standards for solar collectors EN 12976 for ‘intrinsically secure’ design & installation The UK market is now well regulated through the Microgeneration Certification Scheme (MCS) Product & Installation standards for a range of renewable technologies The UK has the world’s longest established trade body for solar technologies… The Solar Trade Association
HERE COMES THE SUN SOLAR for HOT WATER and HEATING: A MATURE & WELL ESTABLISHED TECHNOLOGY Installation standards are much higher in Britain now. A STANDARD SOLAR HEATING SYSTEM … … is INDIRECT, separate from the water we use … has GLAZED, INSULATED solar collectors … has mains-powered circulation pump … uses SOLAR-SPECIFIC components: pumps, valves, insulation etc
HERE COMES THE SUN SOLAR for HOT WATER and HEATING: VERY WIDESPREAD APPLICATION latest global statistics (source: IEA SHC): over 400 million sq.m. solar collector area installed around the world (40,000 hectares = around 56,000 football pitches of collector area) Approximately 300 GigaWatts = 300,000 MegaWatts capacity Around TWO THIRDS of total global capacity is in one country... TOTAL installed solar collector area in UK in 2005 was around 100,000 sq.m. ANNUAL installed area around 100,000 sq.m. in UK now.
HERE COMES THE SUN SOLAR for HOT WATER and HEATING: SOLAR HEATING is a VERY LOW CO2 EMITTING TECHNOLOGY assuming it has been appropriately chosen, well designed & installed… a solar water heating system will: consume around 50kWh of energy a year to run provide between 1000 and 1800 kWh useful energy a year offset a further roughly 25% of efficiency loss for a (modern, efficient) gas boiler TOTAL ENERGY OFFSET perhaps around 1500 to 2000 kWh a year NO NEED TO WAIT FOR THE ELECTRICITY GRID TO GO GREEN OR RELY ON OTHER PEOPLE REPLANTING BIOMASS
HERE COMES THE SUN SOLAR for HOT WATER and HEATING: EFFICIENT CONVERSION of LIGHT to HEAT MAXIMUM CONVERSION EFFICIENCY OF A SOLAR COLLECTOR over 80%... REALISTIC OVERALL SYSTEM EFFICIENCY around 50% compares well to the Internal Combustion engine: around 15 to 20% and very well to PLANT GROWTH, around 1 – 2% This makes SOLAR THERMAL COLLECTORS VERY SPACE-EFFICIENT this helps solar heating systems do a lot with a small area: For solar water heating a collector area of around 4 sq.m. is common For space heating & combi’ systems, a typical collector area is between 6 and 12 sq.m.
HERE COMES THE SUN SOLAR for HOT WATER and HEATING: VERY GOOD for HOT WATER and CAN WORK VERY WELL for HEAT SOLAR CAN WORK VERY WELL FOR HEATING BUILDINGS There are more constraints and complications than for water heating: NEEDS: a well-insulated building that can be heated at lower temperatures (just as for heat pumps to work effectively) a larger collector area and more storage by some means. “COMBI-SYSTEMS” that do heating and hot water are common across Europe, now most of solar collector area installed in Germany, Austria, much of France STORAGE & DISTRIBUITION OPTIONS ARE MULTIPLE & MORE COMPLEX APPROPRIATE DESIGN IS VERY IMPORTANT
HERE COMES THE SUN SOLAR for HOT WATER and HEATING: VERY GOOD for HOT WATER and CAN WORK VERY WELL for HEAT SKYRAD – UK patented design, installed in London & Birmingham, solar thermal & External Wall Insulation for ‘hard to heat’ solid wall buildings - costs around £16,000. Gas savings around 85%, data from installed systems. COMBI-SYSTEMS with THERMAL STORES a range of options available, highly dependent on buildings & occupants’ heat needs
HERE COMES THE SUN SOLAR for HOT WATER and HEATING: SOLAR THERMAL is useful for HOT WATER AND HEAT TYPICAL INSTALLED COSTS – materials & labour SOLAR HOT WATER: system (without storage) £2700 to £3600 high-efficiency hot water store: £800 to £1800 SOLAR SPACE HEATING varies more widely: £8500 to £18000
HEAT & ENERGY USE Over 80% of the energy we use in our homes is for HEAT Average domestic hot water demand around 2,500kWh, though varies widely Typical hot water storage losses between 500 and 800kWh per year Poorly insulated pipework and cylinders can loose up to 2,910kWh per year Well-installed solar water heating system can save 1,500kWh of hot water energy Installation StepEnergy Bill Saving per year More efficient boilerPossibly very large New cylinder with 75mm insulation or added jacket £45 Pipework insulation£15 Solar Thermal£55 replacing gas £88 replacing electric
How does it work? S1S2S3S1S2S3 Collector temperature Upper hot water store temperature lower hot water store temperature When S1 is hotter than S3, the controller switches the pump on, which circulates the heat transfer fluid. This warms the hot water cylinder.
Renewable Heat Incentive 19.2p/kWh for hot water provided by solar water heating for 7 years. The total amount over 7 years ranges between £1,200 and £3,200. Amount of hot water depends on: Occupancy Hot Water Usage Boiler Efficiency Green Deal assessment required for eligibility Loft must be lagged to at least 250mm Cavity walls must be filled. Legacy customers since 15th July 2009 included.