Electricity can be generated from the sun using "solar" photovoltaic (PV) panels. They don't have to be receiving direct sunlight in order to work - any daylight will generate electricity. However full summer sun will generate more power than an overcast day in winter and the more of it the panels receive, the more cost effective they will be. The panels should always be positioned to face somewhere between South East and South West to maximise sunlight. PV panels come in a wide range of different sizes. For larger domestic arrays, grants are available from the Low Carbon Buildings Programme.
Different Uses for PV Technology
PV panels come in various different sizes and can be used for a range of different applications. Very small PV cells can be used to charge all sizes of batteries for home use. Small PV units can be a good solution for providing light and power away from the grid, such as in an outbuilding. Large 12V batteries will be needed to store the power and an inverter will be needed to convert it into useable 240V electricity. Large PV panels can also be installed either with a series of 12V batteries for remote locations unconnected to the grid or they can connected directly into the National Grid. For grid connected systems, bill payers will need to set up an agreement with their electricity supplier, whereby they'll earn money off their bill for electricity generated.
Cost Effectiveness
Prices for PV panels vary hugely, depending on the scale of the technology. Solar battery chargers, for example, begin at about £10, while small off grid panels range from about £250 - £1000. Prices for a large set of domestic panels start at around £7000 (including grant), for 8-10m2 of solar panels. This would generate around 800kWh a year, roughly a quarter of domestic electricity use. The time it takes for such a system to pay for itself due to reduced electricity bills will vary depending on the size of the installation; the bigger the system, the more favorable the payback periods. Payback periods can only ever be calculated based on current electricity prices: if electricity prices go up by 20% the payback periods drop by the same percentage. In 2004, the DTi had predicted a 35% increase in electricity prices by 2010, but it appears now that they have underestimated this. PV panels can be seen as an investment, and have been shown to add to the value of house prices. If installing PV panels, to get the most out of this home made electricity, the building should also be fitted with energy efficient appliances and low energy light bulbs.
Grants
Grants are available from the Low Carbon Buildings Programme to help pay for the cost of pv panels. This can greatly help in shortening the time it takes for the panels to pay for themselves in reduced electricity bills. Grants of up to £2500 are available for domestic installations. Alternatively, around 50% of the costs can be secured for public sector groups. For more information, call 0800 915 0990 or visit www.lowcarbonbuildings.org.uk.
Useful Contacts:
Please note that this list is not exhaustive. The companies listed are offered as a starting point for your enquiries but with no implied recommendation as to their qualities of service to the public.
Southern Solar Ltd
0845 456 1706 www.southernsolar.co.uk
Wind and Sun Ltd
01568 760671 www.windandsun.co.uk
Dulas Engineering
01654 705000 www.dulas.org.uk
Greenearth Energy
01981 241399 www.greenearthenergy.co.uk
Solar Century
0807 735 0100 www.solarcentury.co.uk
Solar Energy Alliance
01502 515532 www.solarenergyalliance.com
The British Photovoltaic Association
www.greenenergy.org.uk/pvuk2/index.html
Energy Saving Trust
www.energysavingtrust.org.uk/housingbuildings/funding/solarpv/
Centre for Alternative Technology
