Basically there are two kinds of solar panels. Solar collectors which heat the water and then there are photovoltaic solar panels which converts solar radiation directly to electricity. Both systems use completely different technology and they are related only because they’re using sun as a source of energy.

Solar collectors (or solar thermal panels) as mention above are used to heat water. Basically it’s a area where water flows on the flat plate or in tubes and solar radiation is used to heat up the water. There is a layer of insulation and often a black absorber plate to make sure that the most of radiation is used. When the water is heated then it’s stored in boiler for further use.

Solar collectors could supply you very large amount of your annual heating needs for a very interesting price.

Photovoltaic panels on the other hand converts solar radiation directly to electricity. The technology is more advanced and materials are more expensive.

A single crystalline silicon PV cell typically produces a voltage of about 0.5V at a current of up to around 3A which is a peak power of about 1.5 W. So to cover your electricity needs you would need a lot of cells.

Photovoltaic is a very interesting topic to which we will return many times in the future.