Some frequently asked questions about solar pv...
A south facing roof is not necessary. Even if your roof faces due east or west, solar panels are still a worthwhile investment. Solar PV panels on a typical UK roof, at a slope of 40 degrees, and facing due east or west will still generate over 80% of the electrical energy compared with one facing due south. For panels facing south-east or south-west the figure is over 90%.
Shading from chimneys, aerials and trees etc is a potentially a big problem when trying to achieve maximum efficiency, so it's important to try to minimise shading wherever possible. Our engineers will be happy to advise you on the best site for your panels. For more information see our Technical Information page and read the section on shading.
Panasonic's HIT solar modules (Heterojunction with Intrinsic Thin layer) have been distributed worldwide since 1997. The HIT solar cell is a mono crystalline solar cell which is encased by an incredibly thin amorphous silicone layer. Panasonic's HIT panels offer the highest efficiency ratings in the market. This means their panels comparatively produce more power per square foot/metre than many competitors’ offerings, and is news for those who have limited roof space and want to generate the maximum amount of power they can. Panasonic's HIT panels are also the best at combating high temperatures . All solar panels’ output decreases as surface temperature increases. Panasonic have worked hard to reduce this effect on the HIT panels offering up to 10% more power per watt than the majority of other manufacturers. They have now been proven to only lose 8% of their total output due to degradation over the 25 years and have the worlds highest conversion efficiency.
When obtaining quotations, it is important that consumers question installation companies about their proposed mounting system. In our opinion, correct mounting is the most important aspect of any installation; the roof structure must not be compromised and the panels must be mounted in accordance with manufactures instructions.
We DO NOT believe that using a "direct style" sales agent is the correct way to conduct a site survey. Typically they will not carry out a full survey of the property, roof structure or even go up a ladder to take accurate shading information. Their only concern seems to be getting the sale and the commission that follows. Go Green Systems DO NOT employ any sales agents, nor do we pay our surveyors commission. We will undertake a full survey looking at every aspect of the installation, answer any questions you may have, show you information on the correct way to install your system, and then return to our office to compile your quotation before we either email or post it to you. This way you can be sure that the output and investment return figures are correct, and more importantly make a decision in your own time without being pressured in any way.
The panels and mounting system must be MCS accredited, consumers sometimes forget the importance of the mounting system! Panels must be accredited for consumers to be eligible for the FIT, thankfully all installation companies adhere to this. However, if a fault was to occur and the mounting used is not MCS accredited; the panel manufactures' guarantee would be invalidated. Inverters do not need to be MCS accredited but they must comply with the standard G83/1 or G59. Generation meters must conform to IEC62053.
In many cases fixing solar panels to the roof of a single dwelling house is likely to be considered 'permitted development' under planning law, so there is no need to apply for planning permission. If your building is listed you are likely to require listed building consent. This is becoming easier to obtain due to new government guidelines, particularly if the roof is not visible from the road. If your property is in a conservation area, an Area of Outstanding Natural Beauty or in a World Heritage Site, planning consent is required when panels are to be fitted on the principal or side elevation walls and they are visible from the road. If panels are to be fitted to a building in your garden or grounds they should not be visible from the road. If you do need permission of any kind, we will be happy to help guide you through the process.
Yes! However, all panels must be properly secured and mounted. There are a number of mounting systems for flat roofs, as you can rarely provide a positive fixing into the roof structure; these systems usually utilise ballast weights. In some cases this can prove to be an issue when trying to satisfy structural calculations. You can even mount panels vertically; so long as they are facing south, you will still achieve over 70% efficiency.