Solar system

A team from MIT has tested a prototype of a new solar power system that consists of a 12ft-wide dish made from a frame of thin, aluminium tubing and strips of mirror.

Attached to the end of an aluminium tube that rises from the centre of the dish is a black coil of tubing that has water running through it. When the dish is pointing directly at the sun, the water in the coil flashes immediately into steam.

Spencer Ahrens, who has just received his master's in mechanical engineering from MIT, hopes that the company he and his colleagues have founded - RawSolar - will produce such dishes by the thousands.

He said they could be set up in huge arrays to provide steam for industrial processing, or for heating or cooling buildings, as well as to hook up to steam turbines and generate electricity.

Once in mass production, such arrays should pay for themselves within a couple of years with the energy they produce.