Stirling Energy Systems’ 25 kW solar dish harnesses the power of the sun to make zero emissions energy. Stirling Energy Systems (SES) is a U.S. Phoenix, Arizona based company and recently (April 17, 2008) they announced that the company NTR plc of the United Kingdom had invested $100 million in them to take a controlling stake. On February 12, 2008 Stirling Energy Systems achieved a record 31.25% net efficiency in the conversion of solar energy to electricity, beating the earlier 29.4% efficiency of a Stirling Solar Dish set by Sandia National Laboratories in 1984.

Stirling Energy Systems’ Solar Dish Engine has the commercial brand name of ‘SunCatcher’ and was developed in 1984 by McDonnell Douglas Corporation and Kockums of Malmo, Sweden. With the acquisition of McDonnell Douglas by Boeing, Boeing assumed the rights to the technology. In 1996 Stirling Energy Systems acquired the patent rights and a license to build the Kockums 4-95 Stirling Engine from Boeing. Boeing and SES continued to work jointly on the development of the Stirling Engine in conjunction with the U.S. Department Of Energy (DOE) as Phase I and II development trials between 1999 and 2001.

Each Stirling-engine solar parabolic dish is 37 feet in diameter and generates 25kW. The solar dish works by reflecting the sun’s rays onto a receiver which transmits heat energy to a Stirling engine. The engine is a sealed system filled with hydrogen. As the gas heats and cools, its pressure rises and falls. The change in pressure drives pistons inside the engine which, in turn, drives a generator to make electricity.