In 1816, the Rev. Robert Stirling a Scottish clergyman from Perthshire, Scotland, patented a device he called the Heat Economizer. The patent describes a power piston, a displacer to move the enclosed air between the hot and cold ends and a regenerator set between the hot and cold ends of the displacer cylinder. Using external heat (sun) the power piston compresses the enclosed air in the cold end of the displacer cylinder. The displacer then shifts the air from cold to hot chambers. The piston is driven back, the power stroke, by the air expanding in the hot end. This movement can be attached to permanent magnets, thus producing electricity.

Today this old technology is used by Infinia to generate electricity. Infinia Corporation is located in Kennewick Washington. The unique design consists of a 15ft. highly polished mirrored dish that tracks the sun for 19 hours a day focusing its rays on the Free Piston Stirling Engine. (Click here to see video) Each engine is capable of producing as much as 3kW of power at 240 VAC. These products are expected to reduce energy costs by 15% and the associated greenhouse gas emissions by over 20%, without any reduction in consumer comfort and satisfaction. Infinia has partnered with Bosch, Rinnai, Merloni, Enatec, Lockheed Martin, NASA and the U.S. Department of Energy (DOE) enabling significant changes in radioisotope-fueled power delivered for future space missions. They have also worked with the Pacific Northwest National Laboratory (PNNL) to develop reliable Stirling Generators that will help protect national security

A single 3kW Stirling Generator will produce over 8MW per year. Each megawatt generated removes 1,867 tons of carbon dioxide, 7 tons of nitrogen oxides and 11 tons of sulfur dioxides from the atmosphere annually. Carbon dioxide avoidance alone is the equivalent of burning over 190,000 gallons of gasoline. The conversion efficiency of 24% enables it to generate up to twice as many kilowatt hours of electricity as Photo Voltaic (PV) systems of similar size. A Stirling Solar system will produce 1.5 MW of power on a 3 acre site versus the 13.5 acres required for generation of that same 1.5 MW using PV based systems. Groups of units can be installed in phases to produce increased power.

In 2008 the City of Belen obtained a competitive “Clean Energy” Grant as part of Governor Bill Richardson’s Clean Energy Innovation Fund from the State Energy Minerals and Natural Resources Department; of the $40 million in requests for $1million in funding the City of Belen was able to secure $100,000 to retro-fit City Hall with new energy efficient lighting, ballasts and solar power generation. The city has matched $5,000 in cash and over $10,000 in-kind services for this project.

The City of Belen and Integrative Solar, the developer for Infinia Corporation, have been working hand in hand to bring to fruition this installation of three concentrated solar power units (CSP) at the Belen City Hall. These generators will feed energy directly to the grid that will qualify the City for “Return Energy Credits” of 15 cents per kilowatt hour. The City of Belen and Integrative Solar have also entered into a development and research collaboration in which Integrative Solar will be monitoring and testing the Infinia equipment on an ongoing basis in the hopes of improving Infinia's technology. This will be the "seed" start up of a hoped for STAR Center being constructed on a 160 acre parcel of land near the Alexander Municipal Airport.

The initiative has inspired local business to also conduct energy efficient audits and solar retro-fits that includes 5 commercial buildings of 10,000 square feet and larger. The initiative has also built new partnerships with the UNM Valencia Campus and the local school district which has conducted a Lighting and Solar Thermal audit for the High School and is on schedule to audit and retro-fit solar power, solar thermal hot water and lighting on the remaining 15 facilities.

The project funds were awarded, to the City of Belen in September 2008, and due to the new Concentrated Stirling Technology, United Laboratories (UL) certification process delayed the installation of the Stirling Generators for several months. The technology is currently certified for commercial use by the European Regulatory Authority and Integrative Solar has a 1 megawatt facility operating in Spain.

		Left, a 200ft. long trench is dug through the parking lot at City Hall that will carry conduit to tie the solar generators to the power grid. Center, workers set up one of the three solar dishes. Right, workers install conduit for the dish controller.