Solar energy
THE SUN'S ENERGY CAN BE CAPTURES AND HARNESSED. THERE ARE THREE MAIN WAYS OF DOING THIS:
1. PASSIVE SOLAR DESIGN ENSURES THAT A BUILDING'S FORM AND FABRIC CAPTURES THE SUN'S ENERGY AND REDUCES THE NEED FOR ARTIFICIAL LIGHT AND HEATING.
2. ACTIVE SOLAR WATER HEATING CONVERTS SOLAR RADIATION INTO HEAT WHICH CAN BE USED DIRECTLY OR STORED.
3. PHOTOVOLTAICS (PV) CONVERT SUNLIGHT INTO ELECTRICITY.
POLLUTION
SOLAR TECHNOLOGIES PRODUCE NO AIR POLLUTION AND EMIT LITTLE OR NO NOISE DURING OPERATION. 1KWP OF SOLAR CELLS DISPLACES 1000KG OF CO2.
DISTRIBUTION
WITH GENERATION AT THE POINT OF USE, TRANSMISSION AND DISTRIBUTION COSTS , AS WELL AS NEGATIVE ENVIRONMENTAL IMPACTS, ARE AVOIDED.
MATERIALS
THERE IS SOME ENVIRONMENTAL CONCERN OVER THE LEAD ACID BATTERIES USED IN SOME SYSTEMS FOR STORAGE PURPOSES. HEAVY METALS SUCH AS CADMIUM ARE USED IN PV CELLS AND CADMIUM SULPHIDE IS USED IN PV PANELS, REPLACING THE MORE EXPENSIVE SILICONE. CADMIUM CAN BE DIFFICULT TO RECYCLE. THE PRODUCTION OF SILICONE HAS AN INSIGNIFICANT ENVIRONMENTAL IMPACT, ALTHOUGH SOME FOSSIL FUELS ARE USED.
CURRENT CAPACITY FOR SOLAR PANELS IN THE UK STANDS AT 4 MW - LARGELY FROM PHOTOVOLTAIC SYSTEMS. THIS IS A TINY PROPORTION OF ITS POTENTIAL.
PASSIVE SOLAR DESIGN IS A PROVEN DESIGN APPROACH THAT CAN BE COST-EFFECTIVE IN TERMS OF REDUCED ENERGY COSTS FOR BUILDINGS. IN THE UK, SIGNIFICANT PROGRESS HAS BEEN MADE TO DATE IN THE NON-DOMESTIC BUILDINGS SECTOR. UPTAKE IN THE HOUSE BUILDING SECTOR HAS BEEN SLOWER, HOWEVER, ITS APPLICATION IS EXPECTED TO CONTINUE TO EVOLVE AND GROW AS A PART OF THE PRACTICE OF GOOD BUILDING DESIGN. BUILDINGS CURRENTLY CONTRIBUTE 47% OF THE UK'S CARBON DIOXIDE EMISSIONS. A SMALL ESTABLISHED MARKET CURRENTLY EXISTS FOR ACTIVE SOLAR HEATING IN THE UK, WITH FAIRLY STEADY HEALTHY PRODUCTION FOR THE EXPORT MARKET SINCE 1989.
INDICATIONS ARE THAT COSTS AND PRICES OF SYSTEMS IN OPERATION ARE FALLING- THIS WILL INCREASE THE ECONOMIC ATTRACTIVENESS OF SYSTEMS AND THE RANGE OF ATTRACTIVE APPLICATIONS. THERE ARE THOUSANDS OF PHOTOVOLTAIC CELLS (PV) TECHNOLOGY SYSTEMS IN OPERATION IN THE UK TO MEET SMALL POWER REQUIREMENTS IN APPLICATIONS SUCH AS PHONE BOOTHS AND ROADSIDE MONITORING SYSTEMS. LARGER-SCALE APPLICATIONS ON BUILDINGS CONNECTED TO LOCAL ELECTRICITY NETWORKS ARE GROWING. HERE THE ELECTRICITY PRODUCED CAN BE 'STORED' BY THE GRID FOR EITHER IMMEDIATE USE OR FOR SALE TO AN ELECTRICITY SUPPLY COMPANY.
LIKELY CONTRIBUTION TO RENEWABLE TARGET
PV CAN DELIVER CLEAN, SILENT ELECTRICITY AT THE POINT OF USE, AND HAS THE POTENTIAL TO MEET A SIGNIFICANT PROPORTION OF OUR ELECTRICITY NEEDS IN THE FUTURE.