The original kinematic Stirling machine, developed over 200 years ago by Rev. Robert Stirling, did not attain significant technical or commercial success until the latter half of the 20th century. An increased focus on this technology over the last 50 years has led to significant recent breakthroughs in terms of operating concepts and supporting technologies. The principal “Stirling advantage” is that it is a closed-cycle external combustion engine, meaning the heat source is outside the engine and the inside of the engine can be sealed. Stirling engines also make use of a regenerative heat exchanger that allows them to re-use their heat. This regeneration feature is what makes the Stirling cycle efficient, in addition to allowing it at the same time to be powered by virtually any heat source (e.g., oil, gas, solar, wood, coal, nuclear, and other combustible natural waste).
Qnergy employs an innovative variant to the well-known ‘classic’ Stirling engine, which is called the Free Piston Stirling Engine (FPSE). Qnergy has introduced additional proprietary designs which monopolize on the fundamental architectural reliability of the FPSE. By employing novel heat exchanger designs within the harmonically resonating thermo-mechanical structure, Qnergy generators transform heat into electricity directly by using linear alternators. Qnergy’s design breakthroughs have resulted in an extremely reliable, long-life, maintenance-free, and quiet, electricity generating platform. Qnergy’s FPSE generators, when heated at their absorber, can literally transform any flow of heat into a steady output of electricity. These same generators are packaged into Qnergy’s energy products, these make use of multiple types of fuels to generate grid-quality electric power.