Is your home suitable for solar panels?

Lots of people want to install solar panels but worry about whether their house is right for them. How should they be aligned and is the roof strong enough? Most houses are suitable for solar and a solar system will work well almost everywhere in the world.

The key thing to check is whether the area where the panels are to be deployed is shaded by trees or buildings for most of the day. If it is, then you will have to look for another renewable energy option. Fortunately most houses are not shaded.

In the United Kingdom you have to be aware of certain planning requirements, but these have changed for the better. Under the new rules every Genersys installation does not need planning permission because the panels will not project more than 150mm above the roof line, so they will not be obtrusive.

Originally the rules were drafted to limit solar panels to 150mm but after of the representations by the Solar Trade Association the allowance was increased to 200mm to allow for fatter solar panels. You still need planning permission if you want to fit solar panels to a listed building, or in a conservation area facing the road.

Virtually all roofs are strong enough for Genersys panels; they are always mounted on a aluminium frame which is fixed to the roof structure below the tiles, or in the case of slates, by self sealing fittings through the slates. The Genersys 1000-10 panel weighs only around 35kg, so a typical two or three panel system will not affect the stability of the roof.

Some councils take the view that as a material alteration, a solar panel installation falls within building regulations. Your installer can undertake the necessary work to notify Building Control locally, and comply with regulations.

If you can fit the panels “within the roof”. In these cases roof tiles or slates are stripped, and the frame is mounted 30mm or so above the roof timber, to avoid condensation between metal and wood. After the panels are fitted in the frame the tiles are laid back to the panels and surround by flashing to create a watertight fit.

“In roof” systems have the advantage of preventing heat losses underneath the panels by wind, and the weight of the panels is almost always less than the weight of the tiles that they have replaced.

What about the orientation of the panels? Thermal solar panels work by converting daylight into heat. You do not need direct sunlight to get the panels working, but they will work quicker in direct hot conditions. In the United Kingdom most thermal solar systems provide hot water but there is an increasing take up for also using them to provide space heating and pool heating.

Solar thermal panels are usually fitted to a south facing roof. If the panels are selectively coated (like all Genersys panels) they do not need to be fitted facing due south (or due north in the southern hemisphere) – south east or south west will suffice. There will be a moderate loss of performance in the winter months but performance in summer will not be affected, because the daylight hours are longer.

If your roof has slopes that face east and west you can still fit solar; you fit an array on each slope and program the digital controller to react to the array that is collecting the most energy. In fact, an east/west pitch will provide better performance than a south facing pitch although it is a more expensive option.

If you have a flat roof you can arrange the orientation and pitch of the panels precisely. Ideally, they should face due south and incline to 10 degrees less than the latitude of your property. The reason for this is that in summer placing the panels at an angle which does not provide the most area of concentrated light will not affect performance at all, but in winter, lowering the angle will enable more concentrated light from a sun low on the horizon and improve performance.

It is possible to mount Genersys panels vertically, virtually horizontally, on racks or A frames and on every type of roof, as you can see from the pictures. You can get a good idea of the range of roof fittings from the installation manual at http://www.genersys-solar.com/downloads.asp?ID=82

All these rules theoretically provide for the best “performance” but in practice the additional energy gains that you can achieve by perfect alignment pitch and orientation can easily be outweighed by poor installation, so it is important to have your panels fitted by a qualified installer who has been approved by the manufacturer.

At Genersys we have introduced a system of approved Genersys Installers. Once a system has been installed by a Genersys Approved Installer Genersys will guarantee the panels for twenty years, but if you do it yourself (not recommended) we will not provide you with such comfort.