The World Leader in Free-Piston Stirling Engines and Cryocoolers

Welcome to Sunpower, Inc.

Sunpower is the world leader in free-piston Stirling technology. Our reputation for producing reliable and efficient Stirling engines and cryocoolers is known world-wide.

Sunpower’s engineering services include prototype design, development and fabrication of free-piston Stirling engines. The CryoTel® line of cryocoolers has outstanding performance, manufacturing accuracy, and quality. We invite you to contact us for more information about our services or products.


    For over 10 years Sunpower’s M77 cryocooler has cooled Germanium detectors continuously aboard the RHESSI satellite to study solar flares. It was launched on February 5, 2002. Thanks to its longevity and the data the mission has provided the science community, RHESSI is continually one of NASA’s highest rated scientific missions. The original mission was planned for 6 months of study. Read More

  • ASC
    Sunpower’s Advanced Stirling Convertor (ASC) has been selected by NASA for integration in the Advanced Stirling Radioisotope Generator for potential space missions. The use of the ASC in space radioisotope power systems reduces the required mass of fuel by a factor of 4 compared to existing technology. Read More

  • Mission Downselect(NASA)
    Read More

  • ASC-E3 Stirling Convertor
    Sunpower, Inc. operates the first ASC-E3 Stirling Convertors, generating electrical power in a test cell within the company’s Athens, Ohio facility using electrically-generated heat to simulate a space systems heat source. The Advanced Stirling Convertor is integrated into the Lockheed Martin Advanced Stirling Radioisotope Generator that may be selected for potential NASA Discovery Class missions scheduled for launch in 2016.