Solar

Solar is also a good source for solar energy. The suns energy can be captured in the form of heat or light. The technology could be:

Photovoltiac (PV) panels that produce electricity;

Thermal solar panels that produce hot water or;

Solar hot air panels that capture heated air and distributes this around a building.

(links are to Greenspec website)

There are a number of pros and cons with each of the technologies. So to take each in turn.

Photovoltiacs. These are expensive at the moment, although technology is changing fast and new generations of equipment are being developed all the time. These produce electricity and this is a very precious source of energy since we are using more of it to power items like electronic gadgets. For the panels to be effective you will need to have an unshaded area to place them. They are approx. 5 - 12 % efficient and take a certain amount of energy to produce in the first place. For a typical 3 be3droom house with a family, you will have to look at about £ 8,000 in order to get a reasonable amount of energy back. The system also needs to be two-way, so that you can sell units back to the grid. This can be quite lucrative, since energy companies are desperate for energy produced in this way, so there are cases where people are getting paid 50% more for their renewable energy than they are actually paying for it.

Solar thermal is probably the most cost effective way of generating energy for the home. The technology is well tested and has proved itself to be easy to maintain. However it does need to be integrated with your existing systems for heating water, so it is better to go for a professionally installed system that compliments your existing energy source and lifestyle. Control systems are key to having an efficient hot water and heating system. Combi-boilers are not generally compatible with solar thermal systems, although new boilers are becoming available that will take a hot water input. Again with solar systems you will need a south facing roof for them to be most efficient.

Solar Warm Air. This is the least common and least proved of the solar technologies. However it can work very well and it stops the problems of integrating the existing systems together as the thermostat that controls the boiler will automatically take this additional input into account. It does however require additional conduits for the air in the house, so it is more difficult to retrofit, unless you are just installing in the top storey.