Solar Power Generators | Solar Trough & Tower Systems

By far the most common of Solar Power Generators is the Solar Trough System. Solar troughs use the heat from the Sun rather than converting light into electricity. The system depends upon a series of parabolic mirrors, which concentrate the Sun's heat onto a pipe containing special oil, which sits in the trough. The oil is heated up to nearly 400ºC and is pumped to a generating station where it passes through a heat exchanger. Here heat is passed to water, which is converted into steam. Electricity is produced by a steam turbine.

The Solar Tower acts on the same principle as the trough except that the heat transfer fluid is situated in a receiver at the top of a tall tower. Many hundreds of mirrors concentrate the heat of the Sun onto the receiver, where the fluid, in many cases liquefied salt, is heated and pumped to a heat exchanger. Once again water is heated here into steam and this drives a steam turbine to generate electricity.

Another Solar Tower is presently being considered for the future - this one in the form of a very large greenhouse in the center of which is a very tall tower. Hot air from the greenhouse rises up the tower and drives turbines on the way, so generating electricity. This method is considered quite feasible in countries like Australia, where there is a lot of room and sunshine.

A third type of generator utilizes an array of mirrors in the shape of a dish. This focuses the Sun's heat onto a collector where the heat is converted into electricity by means of an engine, typically a Stirling engine or a Brayton-cycle engine. This type of generator under test at several locations around the world has shown a conversion efficiency of around 30%, much higher than photovoltaic generators have achieved to date.

Several multi-million dollar power stations using photovoltaic technology are in the planning stage in Europe. One is planned in Portugal where 116 clusters of solar panels are to be erected on a 620 acre site. A 15 megawatt solar power station is currently being built in South Korea and Israel is planning a 100 megawatt power station in the Negev desert.

On a smaller scale, all of those solar powered homes that contribute to the Grid in even the smallest way are solar power generators.