Otherwise known as PV’s or SOLAR PANELS; these are rectangular flat devices that face the sun and generate electric power from its light. The energy of photons is used to energise electrons in the PV’s laminations). Three types of PV cells exist;
"Mono's" are the smallest cells and they generally last a little longer. Poly’s are slightly larger, whilst Amorphous cells cope well with high temperatures but are significantly larger and have a shorter life-span (they are, however, slightly cheaper).
A PV array is generally easy to install and the modular nature of such a system allows for easy additions later on. A south facing roof of any pitch is ideal. The solid state technology employed in the production of PV’s means that they are very reliable, lasting 30+ yrs.
If PV’s on their own have a drawback it is that they generate most power in the summer when it is not always needed, and less power in winter when needs are often greater. For this reason PV systems are often appropriately used on a seasonal basis (summer holidays) or incorporated as part of a WIND/PV hybrid system. Where cost is not so important a PV only system will provide year round power, however the number of modules, and hence cost, will be significantly greater. Planning permission is not usually required for PV’s.
The most common and least expensive PV systems consist of a PV array 'bolted on' to the roof, this means that it stands up slightly proud of the roof. More integrated systems involve removing the slates or tiles, fixing the array to the rafters and then re-fitting the slates/tiles around the array forming a waterproof barrier (similar to a Velux roof window). Also available, though more expensive, are 'Solar Slates/Tiles' which mimick the look of normal slates/tiles - though these integrated systems cost more.
Typically, in Southern UK, 4 KW of PV panels (8m x 3.5m) will generate about 4,000KWh (units) of solar electricity per year - a 2KW system will produce half...
Typical costs (through SUSTAINERGY) are in the region of £1,500 per KW including installation.
Site-assessment visits should be arranged prior to ordering: We will come and look at your roof and house, chat to you informally and prepare a quote for an appropriate PV system - just phone us!