Solar panel electricity systems, also known as solar photovoltaics (PV), capture the sun’s energy using photovoltaic cells. These cells don’t need direct sunlight to work – they can still generate some electricity on a cloudy day. The cells convert the sunlight into electricity, which can be used to run household appliances and lighting.
PV cells are made from layers of semi-conducting material, usually silicon. When light shines on the cell it creates an electric field across the layers. The stronger the sunshine, the more electricity is produced. Groups of cells are mounted together in panels or modules that can either be mounted on your roof or on the ground.
The power of a PV cell is measured in kilowatts peak (kWp). That’s the rate at which it generates energy at peak performance in full direct sunlight during the summer. PV cells come in a variety of shapes and sizes. Most PV systems are made up of panels that fit on top of an existing roof, but you can also fit solar tiles.
Solar tiles are designed to be used in place of ordinary roof tiles. A system made up of solar tiles will typically cost about twice as much as an equivalent panel system. Solar tile systems are not normally as cost-effective as panel systems, and are usually only considered where panels are not considered appropriate for aesthetic or planning reasons.
A 4kWp system can generate around 3,800 kilowatt hours of electricity a year in the south of England – that’s the same amount of electricity as it takes to turn the London Eye 50 times. It will save nearly two tonnes of carbon dioxide every year. A 4kWp system in Scotland can generate about 3,200 kilowatt hours of electricity a year – that’s the same amount of electricity as it takes to turn the Falkirk Wheel 2,100 times. It will save more than a tonne and a half of carbon dioxide every year.
The average domestic solar PV system is 4kWp and costs £5,000 – 8,000 (including VAT at 5 per cent).
|Location||Feed-in Tariff generation and export payments based on a 4Kw PV system (£/year)||Electricity bill savings (£/year)||Carbon dioxide (kgCO2/year)|
|System eligible for the tariff between 1st July 2016 and 30th September 2016 (Q3)||System eligible for the tariff between 1st October and 31st December (Q4)|
|CAP NOT REACHED||CAP NOT REACHED|
|London, South England||£255||£255||£240||£70||1,900 kg|
|Aberystwyth, Wales||£240||£240||£225||£70||1,770 kg|
|Manchester, North England||£230||£225||£210||£70||1,670 kg|
|Stirling, Scotland||£220||£210||£200||£70||1,580 kg|
Tariffs will also be subject to an adjustment for RPI (Retail Prices Index) so may change from those stated in this table.
For more information about the FITs scheme and recent changes please visit Feed-In Tariffs.