How solar PV works
Photovoltaic (PV) solar cells/panels are renewable electricity-generating systems, which are installed at an optimal angle on a supporting roof or wall. Each solar cell is made from one or two layers of semi-conducting material, such as silicon. When solar energy (photons) reaches each cell, it creates an electric field across the layers. The stronger the sunlight the more electricity is produced, but solar PV can also generate energy in overcast conditions. The strength of a PV cell is measured in kilowatt peak (kWp), which is the amount of energy the cell generates in direct sunlight.
The benefits of solar PV electricity
- lowers carbon emissions: solar PV electricity is renewable once its installation’s carbon payback time is accounted for
- lower fuel bills: electricity bills could be reduced by as much as £250 per year. A typical home PV system can produce around 50% of the electricity of an average household in a year.
- can export electricity back to the grid: if system is producing more electricity than needed, or at times during the day when householder is not at home, someone else can use it – by either exporting by a private wire or to the grid
- energy storage options: if a home is not connected to the grid, excess electricity can be stored in batteries
Solar PV certification
At micro-level <50kW, there are MCS standards for solar PV installer companies and products. MCS installers and products are mandatory for FITs and installer companies must belong to a consumer code of practice. There are also routes for any complaints through MCS. At the moment there is no other certification scheme considered ‘equivalent’ to MCS but if there were, it would also have access to FITs.
Grants
Grants are available for a range of microgeneration heat technologies which meet the criteria of the Renewable Heat Premium Payments Scheme (RHPP).
Microgeneration heat technologies which meet certain criteria will be eligible for financial incentives (Renewable Heat Incentive).
Permitted planning
Getting planning permission can be a barrier to householders wishing to install microgeneration technologies. In England and Scotland, changes to permitted development rights were introduced on 6 April 2008 and 12 March 2009.
The General Permitted Development Order (GPDO), or the Town and Country Planning (General Permitted Development) (Domestic Microgeneration) (Scotland) Amendment Order 2009 grants rights to carry out certain limited forms of development on the home, without the need to apply for planning permission.
Most solar PV became eligible for permitted planning as a result. For further details see the:
Sources of further information about generating your own energy
Suitable technologies
- For a 'home energy selector' to advise on suitability of a particular property, see the Generate your Own Energy pages on the Energy Saving Trust's website.
Suitable products
MCS installer companies are able to give consumers advice on specific products and impartial advice on the suitability of individual technologies. They are required under MCS standards to give accurate written estimates of likely energy outputs from a technology.
Further information
Carbon Trust guide: A Place in the Sun
This guide on the selection, installation and operation of solar PV technology in low-carbon buildings is based on experiences from the Low Carbon Buildings Programme.