MIT prototype solar dish (Low-cost system could revolutionize global energy production)

A team led by MIT students this week successfully tested a prototype of what may be the most cost-efficient solar power system in the world--one team members believe has the potential to revolutionize global energy production.

The system consists of a 12-foot-wide mirrored dish that team members have spent the last several weeks assembling. The dish, made from a lightweight frame of thin, inexpensive aluminum tubing and strips of mirror, concentrates sunlight by a factor of 1,000--creating heat so intense it could melt a bar of steel.

To demonstrate the system's power, Spencer Ahrens, who just received his master's in mechanical engineering from MIT, stood in a grassy field on the edge of the campus this week holding a long plank. Slowly, he eased it into position in front of the dish. Almost instantly there was a big puff of smoke, and flames erupted from the wood. Success!

Burning sticks is not what this dish is really for, of course. Attached to the end of a 12-foot-long aluminum tube rising from the center of the dish is a black-painted 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.

Someday soon, Ahrens hopes, the company he and his teammates have founded, called RawSolar, will produce such dishes by the thousands. 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.