Tel: 0845 671 5548
Fax: 0845 071 0766
 
Home      Solar Photovoltaics
Solar PV (Photovoltaics)
 
Solar PV is a renewable energy system which uses photovoltaic modules on the roof of a building to convert light into electricity. Voltaic cells are made up of thin layers of semi-conducting material (usually crystalline silicon) which generate an electrical charge when exposed to direct light, producing a direct current. This direct current (DC) is then fed into an inverter which changes it into a usable alternating current (AC).
 
 
 
 
 
Solar PV (Photovoltaics) FAQs 
 
Where can a Solar PV (Photovoltaics) module be installed?
The location of the PV is vitally important. The modules must receive the maximum amount of day light possible, so it is not advised to install the modules in a situation where surrounding buildings or trees may cast shadows. The best location for a PV solar module is on a south-facing roof.

What is the difference between Solar Thermal & Solar PV (Photovoltaics)?
Solar Thermal involves water heating collectors which are very different from PV modules. In Solar Thermal water passes through pipes in the solar collector and the sun heats the water. This type of system will only produce hot water and installation will involve changes to your plumbing and heating system. PV solar modules generate electricity, which is generally used to power appliances. Installing a Solar PV (Photovoltaics) system causes little disruption to your home because apart from a meter and switch which can be installed by your main fuse box, all the components are outside or in your loft.
 
What happens when the weather is cloudy or cold?
Solar PV uses light to generate electricity, so the modules still work when it is cloudy, although when it is overcast they are less efficient. When it is slightly overcast, the panels may produce as much as half the power they would in sunny conditions. When the sky is heavily overcast, this could reduce further. Temperature is less important than how much light there is. What’s more, a clear cold day is perfect, because PV modules operate better at cooler temperatures.
What happens if the Solar PV (Photovoltaics) modules get dirty?
Solar PV modules are self cleaning when mounted at an angle of at least 15º. The amount of dirt on the modules depends on their location. If the modules are in a heavily silted area (e.g. under trees) the build up of dirt may reduce the power the panel generates by around 10%.

What is the expected life span of a Solar PV (Photovoltaics) system?
Most solar panels have a lifetime of around 30 years. The PV modules we supply come with a twenty-five year performance guarantee.

How much electricity can a Solar PV (Photovoltaics) system produce in a year?
A 2kW Solar PV System (approximately 16 modules) should produce around 1,600kWh of electricity per annum. To put this into perspective, 2kWh should run the lighting in an average household using low energy light bulbs for approximately one week.
 
 
Solar PV & Your Home

You can use PV systems for a building with a roof or wall that faces within 90 degrees of south, as long as no other buildings or large trees overshadow it. If the roof surface is in shadow for parts of the day, the output of the system decreases.

Solar panels are not light and the roof must be strong enough to take their weight, especially if the panel is placed on top of existing tiles.

Solar PV installations should always be carried out by a professional installer.

Cost & maintenance

Prices for PV systems vary, depending on the size of the system to be installed, type of PV cell used and the nature of the actual building on which the PV is mounted. The size of the system is dictated by the amount of electricity required.

Grid connected systems require very little maintenance, generally limited to ensuring that the panels are kept relatively clean and that shade from trees has not become a problem. The wiring and components of the system should however be checked regularly by a qualified technician.

Stand-alone systems, i.e. those not connected to the grid, need maintenance on other system components, such as batteries.

Planning considerations

In England, changes to permitted development rights for domestic renewable technologies mean that  most solar PV installations don’t require planning permission, as long as they respect certain size criteria. Exceptions apply for installations on flat roofs, Listed Buildings, and buildings in Conservation Areas and World Heritage Sites.

In Wales, Scotland and Northern Ireland, the devolved governments are currently all considering changes to their legislation, to make installations of microgeneration technologies easier. Legislation is expected in all three countries later this year. Until then, householders in Wales, Scotland and Northern Ireland must consult with their local authority regarding planning permission.

 
 
Why not contact Conservenergy today to discuss how you can dramatically reduce your energy bills.

We provide you with a no obligation quotation together with a free energy efficiency check.
© Copyright Conservenergy 2008