There are a number of methods which can be used to harness the sun's energy

Solar cells or photovaltaic (PV) cells convert light into electrical energy. In a sunny climate, a solar panel with an area of 1 square metre will power a 100 W light bulb. They can be used in many situations and many people own calculators powered by solar cells (often called photoelectric cells)

Another possibility is the use of glass panels to heat water on a roof. This reduces the amount of gas/electricity needed to heat the water at home. Water is pumped through pipes in the panel which gets hotter when the sun shines. The pipes are painted black to improve the efficiency of this and the water is pumped in at the bottom so convection can help the hot water flow out at the top. These systems work effectively in sunny climates such as California and Australia. As the technology improves they will become wothwhile in the UK but care must be taken to prevent the water in the panels freezing in winter.

More advanced solar panels exist and such panels can supply 90% of a typical homes hot water needs between April and November. These panels are specially designed to absorb solar energy including infrared and ultrviolet radioation and reduce losses. If used effectively they could reduce fuel bills dramatically.

Solar furnaces use complicated systems of mirrors to focus the sun's energy on a small area and produce very high temperatures. The solar furnace at Odeillo in France is used to conduct experiments and temperatures of 3000 degrees Centigrade (approx) have been achieved.

Solar cells are ideal for use in situations where an energy supply is difficult to obtain. They provide the energy required to power the satellites orbiting the earth which provide us with TV, telephones, navigation, weather forecasts and many other important facilities. Solar powered boats exist such as the one used on Lake Coniston in the UK. Many people own solar powered garden lights

Solar power is free, it needs no fuel and produces no waste or pollution. It is ideal for low power uses especially in sunny climates and can be used to reduce fuel bills

Solar panels are expensive and a large initial investment is required which may take a long time to recover. They don't work at night and are unreliable unless you live in a sunny climate. In the UK, unrealistically large solar panels are needed to produce an acceptable amount of power.

Grants are available in the UK to install solar power domestically.