Solar panels - photovoltaics
This section covers photovoltaic (PV) electricity generation. PV technology is often referred to simply as ‘solar panels'.
- Why use PV?
- Cost and funding
- Project timescales
- How and where PV works
- Practical issues
- Case studies
- Useful links: where to find out more
Why use PV?
- Until 2013 electricity generated by PV receives generous subsidies from the feed-in tariffs - see Glossary. Also, the price for panels is reducing dramatically.
- It's a versatile technology. It can be used in urban or rural areas on roofs, facades or the ground.
- They are very low maintenance.
- The energy payback is good - currently between two and five years in European conditions.
- They are electricity generating and so it is not possible to over-size the panels in locations close to a grid connection.
Further information about the benefits of PV to the community and environment, as well as the potential impacts of using PV is available here:
Cost and funding
Typical costs for PV are:
- up to £4,000 per kW for systems integrated in new build projects
- up to £5,250 per kW for systems retrofitted on existing buildings.
However, costs are reducing rapidly and larger systems can cost less than £3,000 per kW.
Payback for PV is currently between eight to 13 years depending on the size of the project and whether you use the generated electricity or export it to the grid.
PV is eligible for the feed-in tariffs. For more information about the feed-in tariffs see:
Further information on costs, income generation and payback periods is available here:
Timescales will depend on whether you are adding PV to an existing building or incorporating it as part of a wider new development.
For domestic or small scale PV projects the process is likely to take between two and eight weeks. This is from the time the design has been agreed, in cases where planning permission is not needed.
Commercial PV schemes will take longer due to their complexity and need for planning permission. Installers indicate that 18 months is likely to be the longest time from inception to generation.
How and where PV works
Photovoltaic cells convert sunlight directly into electricity. The cells are made of semiconductor materials like silicon. They will work on a cloudy day, but more energy is produced when the sun shines directly on the cells.
A typical system has one or more modules (or panels) of PV cells arranged in an array.
The diagram on the right shows how arrays can be connected to the electricity distribution grid via an inverter and a meter. PV can also be used where there is no access to the grid, and can be connected to a battery to store power for times when demand exceeds generation.
PV is relatively versatile. Opportunities are principally determined by size and location. PV can be installed on roofs, facades, car parks, railway embankments, vacant land or fields.
Issues such as which direction the building faces and whether any structures would cast a shadow on the panel are also important considerations. Detailed information is provided in the PV project checklist below under 'Practical issues'.
Further information on where PV can be installed, what types of PV are available, and some of the more detailed considerations for managing installation and maintenance is available here:
PV modules have no moving parts and so once they are installed they will require minimal maintenance. Annual checks are recommended.
Prior to installation there are a lot of practical issues to check. Here you will find information on whether or not planning permission is needed for PV projects:
Here are some examples of how some councils are already using solar panels:
Useful links: where to find out more
Making Feed-In Tariffs work for you, A toolkit for local authorities and housing associations, Energy Saving Trust 2010 - on the Energy Saving Trust website
24 April 2012