Energy Facts

Solar PV

Solar PV is a simple sustainable energy technology, with no moving parts, converting sunlight (photons) into electricity.

Each PV cell consists of one or two layers of a semi-conducting material, usually silicon. When light shines on the cell it creates an electric field across the layers, causing electricity to flow.

Solar electricity is free, energy-saving, and environmentally friendly. It requires no maintenance and incurs no running costs.

The sun does not have to shining brightly for Solar PV systems to work. Solar PV generates electricity in daylight, not just sunlight, although the more intense the light, the greater the flow of electricity.

There is a wide variety of technologies available but fundamentally they are available in panels which can be fitted on sloped roofs, on vertical facades or be used as replacements for glazing units. The average domestic Solar PV system can reduce carbon dioxide emissions by 650kg per year. Solar PV systems produce no greenhouse gases. A typical domestic system can save approximately 1.2 tonnes of carbon dioxide per year, adding up to almost 30 tonnes over a system's lifetime, depending on the fuel replaced.

The PV cells are most efficient when facing south and installed at an angle of 30°. The size of the system for a typical home is limited by the availability of suitable orientated roof area or façade. Around 1kWp or 8m² of panels can provide around 800 kWh and reduce the carbon emissions by around 350 kgCO₂ per year.

The PV panels are connected to an inverter that could be located in the loft. It converts the direct current generated by the PVs to alternating current to allow it to be used directly in homes.