cheap, green electricity from sunlight
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.
How do solar panels work?
- Cut your electricity bills: sunlight is free, so once you've paid for the initial installation your electricity costs will be reduced.
- Get paid for the electricity you generate: the government's Feed-In Tariffs pay you for the electricity you generate, even if you use it.
- Sell electricity back to the grid: if your system is producing more electricity than you need, or when you can't use it, you can sell the
surplus back to the grid
- Cut your carbon footprint: solar electricity is green, renewables energy and doesn't release any harmful carbon dioxide] or other pollutants. A
typical home solar PV system could save over a tonne of carbon dioxide per year - that's more than 30 tonnes over its lifetime.
- 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 be mounted
on your roof.
- " 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 and Slates - Solar tiles are designed to be used in place of ordinary roof tiles. A system made up of solar tiles will typically cost
around twice as much as an equivalent panel system, although you will save the money you would have spent on roof tiles or slates. 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.
An average domestic system size is around 3kWp. The Department of Energy and Climate Change (DECC) undertook an assessment of solar PV system costs in May 2012
and based on the results of this a 3kWp system will cost around £7,700 (including VAT at 5%).
Read the full DECC assessment of solar PV systems at the DECC website.
Other factors that affect PV installation costs are:
- The more electricity the system can generate, the more it costs but the more it could save.
- Larger systems are usually more cost-effective than smaller systems (up to 4kWp).
- PV panels are all around the same price per kWp, but PV tiles cost much more than a typical system made up of panels.
- Panels built into a roof are more expensive than those that sit on top.