FAQ Solar Electricity / Photovoltaic (PV)
How does Photovoltaic (PV) work?
A charge is placed across the cell and as the energy from the sun hits the silicon, an electron is released from the atom. Due to the charge across the cell, this electron then flows towards the positive layer. Once you have an electron flow, a current is generated. This direct current is converted by an inverter in the system to an alternating current (AC) at the same level as the national grid.
What happens when I produce more electricity than I need?
When your PV system produces more electricity than you need, the surplus will flow back into the national grid. Your electricity supplier will pay you extra for this surplus power, to reduce your future electricity bills.
Why should I consider a PV solar system?
PV solar systems are easy to install with minimal disruption and have no moving parts so they are also maintenance free. PV is now a mature technology, is guaranteed at 80% efficient for 25 years plus, creates no pollution and is silent when operating.
What are the disadvantages to using PV solar system?
The only disadvantage is the cost; however this is offset by the generous grants currently available and the forthcoming feed in tariff. The average system should pay for its self in 7 to 10 years.
How big a PV solar energy system do I need?
The size of solar system you need depends on several factors such as how much electricity you use, how much daylight is available where you are, the size of your roof, and how much you’re willing to invest. After talking through your requirements we will recommend the size of system you use.
What maintenance and cleaning do the systems need?
PV Solar systems are silent in operation, have no moving parts and require very little maintenance. Dust or dirt may cause a power reduction. The modules can be cleaned with a hose and clean water.
How long do should my PV systems last?
Your PV Solar system is guaranteed operate at 80% for 25 years plus, with an expected lifetime exceeding 40 years.
Will it still work on a cloudy day?
As the electricity generation is dependant on light intensity and not direct sunlight it will work in cloudy conditions but the greater the intensity of the light the greater the flow of electricity. Hence you generate more on sunnier days but the system will still produce electricity on cloudy days.
Will it produce greenhouse gases?
PV systems generate electricity without producing emissions of greenhouse or any other gases. Based on the current electricity mix, every kWh of electricity delivered to your premises from the national grid will have produced 0.43 grammes of CO2. At 800kWh per kWp this will save approximately 344g of CO2 emissions every year. Over the warranty period this is over 8 tonnes of CO2 saved.
Where can I install a PV system?
A PV system should not be installed in shade such as from other buildings or large trees since this will decrease the output from the system. However, although generally installed on a roof, they can be installed on any surface such as facades, sunshades, garages or ground mounted. They are normally installed in locations that receive sunshine through most of the day i.e. from East through South to West. However, maximum output will be facing due south and between 30-40 degrees from horizontal.
Do I need planning permission?
Some authorities require planning permission especially for listed buildings or within a conservation area. Although planning permission for solar PV is not generally required, however we recommend that our customers should always check with their local authority before having a system installed.