SunCatcher - exceeds efficiency goals - Wins Huge Contract

Usually solar power of any sort has a basic problem of being low yield /low energy density. Suncatcher by Stirling Energy is breaking all barriers with a 30% efficiency solar concentrated modular system that has won a pair of huge contracts for SoCal Edison to be installed in Imperial Valley and brought online in less than 2 years.

As Reported In Popular Mechanics and other sources, this breakthrough is really the first solar farm of such a scale that can seriously power the peak load daytime use of a good sized city. And in essence it is simple, modular and relies on technology that harkens from thermodynamic engines.. the Stirling cycle. Very Cool… At the focal point of each dish is a self contained unit that is a heat collector - Stirling motor that spins a generator.

“Planted in the New Mexico desert near Albuquerque, the six solar dish engines of the Solar Thermal Test Facility at Sandia National Laboratories look a bit like giant, highly reflective satellite dishes. Each one is a mosaic of 82 mirrors that fit together to form a 38-ft-wide parabola. The mirrors’ precise curvature focuses light onto a 7-in. area. At its most intense spot, the heat is equivalent to a blistering 13,000 suns, producing a flux 13 times greater than the space shuttle experiences during re-entry. “That’ll melt almost anything known to man,” says Sandia engineer Chuck Andraka. “It’s incredibly hot.”

The heat is used to run a Stirling engine, an elegant 192-year-old technology that creates mechanical energy from an external heat source, as opposed to the internal fuel combustion that powers most auto­mobile engines. Hydrogen gas in a Stirling engine’s four 95 cc cylinders expands and contracts as it is heated and cooled, driving pistons to turn a small electric generator. The configuration of the dish and engine represent the fruit of more than a decade of steady improvements, developed in collaboration with Arizona-based Stirling Energy Systems.

Here is  the best part. Usually people think that solar power should be done in Hot climates only. This Technology actually works better in cool ambient air and bright direct sunlight, since the Stirling cycle of heat/cool relies in part on thermal differentials. The System basically just needs clean mirrors and low cloud density.

The challenge remaining is to turn the prototypes into a low-cost, mass-producible design—“just a question of good, old-fashioned engineering,” according to Osborn. To that end, Stirling Energy signed the two largest solar energy contracts in history with two Southern California utilities, promising to build up to 70,000 SunCatchers and provide power for a million homes. Construction starts next year.

http://www.stirlingenergy.com/default.asp