Solar Energy - energy from sunlight - is very versatile. It can be used to generate electricity, light and heat buildings and create hot water. Solar power could generate 10,000 times more energy than the world currently uses.

Converting sunlight into electricity

Sunlight is converted to electricity by the use of Photovoltaic cells, or solar cells. A PV cell consists of a semiconductor (similar to what transistors and computer chips are made of) that absorbs the sunlight and converts it into electricity. These cells are mounted into modules that hold about 40 cells, and in turn, about 10 modules can be used together to form an array. An array can be used to generate electricity for a building.

Converting sunlight into hot water

Solar hot water systems consist of a solar collector, which is mounted on the roof facing the sun, and a storage tank, to store the heated water. The solar collector heats an absorber plate in the collector, which in turn heats the water, which is running through tubes inside the collector. The heated fluid is moved either by pump or gravity. (The gravity method works because hot water will tend to circulate as it is heated.) Solar heating systems can also be used to preheat air coming into a building.

Passive solar gain

Passive solar gain is simply arranging a home or office to take the best advantage of sunlight, both for heating and lighting. Examples of this include: Adding a conservatory. A well designed conservatory acts as extra insulation for the house, preheats the air, and provides direct solar heat to the wall to which it is attached, which in turn is passed into the house.Facing the main glazed areas to within 30° to either side of south.

Main living areas, such as living rooms and bedrooms should face south and have large glazed areas.Less used areas should face north and have smaller glazed areas.Cut back trees and undergrowth to allow the sun to reach the walls and windows of the house.