Electricity can be produced directly from sunlight by the Photovoltaic effect. Crystals of silicon semi-conductors when subjected to light cause electrons to move and produce a voltage (DC). The PV cells are connected together to form a module (solar panel) and modules linked to form an array which can be roof mounted.

There are no moving parts and apart from cleaning dust etc. from the array there is no maintenance. Panels are guaranteed to produce not less than 80% of stated output after 20 years.

How much power can a PV system produce?
Systems are usually between 1 and 5kW and can meet between 25% and 100% of a households needs. A typical household will consume around 3-4000kWh annually.

Approximately each kWp installed costs between £5000 and £6000.

50% of the cost is met by the Solar Grant scheme (see link on previous "sun" page for information).

Unless your household's electricity consumption is very high it is likely that at midday in bright sun the PV system will be generating more electricity than is being consumed by your electrical appliances.

In this case export of electricity to a supplier arrangement (i.e Grid Connect) would be an advantage and highly recommended.

Solar PV Installers list


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A basic PV diagram.