'What are Solar PV Tiles?' is a question frequently asked by people who are wondering how they can best incorporate a system of renewable energy into their homes. These photovoltaic (PV) roof tiles are sized so that they can be integrated into an existing roof when the covering is replaced. They can help to supply a family's energy needs even on cloudy days.
Each roof tile consists of a photovoltaic module with a glass laminate covering. The tile's assembly uses a semi-conductor material to covert photons of light into electricity. A tile does not require direct sunlight to generate energy, although the amount of energy it produces is dependent on the intensity of light it receives. A PV roof tile system is most efficient when oriented towards the south.
Electrical connectors link the solar roof tile modules to each other and to the house's electricity supply. During the day, the sun's energy will be harnessed to power the household. In times where home electricity use exceeds the amount of renewable energy generated, it will be supplied by a utility company in the usual manner.
Under a UK government sponsored scheme called 'Clean Energy Cashback', utility companies are required to buy any surplus electricity generated from renewable sources. A complete roof tile system includes an import/export meter which keeps track of the amount of energy sourced from or provided to the network.
Total annual energy produced by a photovoltaic roof tile system varies in the UK according to latitude. Roof systems in Southwest England produce about a third more electricity than those in Scotland due to the available light. Since hours of daylight vary with the seasons, more energy is produced in summer than in winter.
Solar PV tile systems can be used on roofs with pitches between 17.5 and 60 degrees from the horizontal. Planning permission is not usually required unless a building is listed or in a conservation area. A trained roofing contractor can install the tiles using standing components.