9 kW Stirling Engine for Natural Gas and Biogas

Small, decentralised Combined Heat and Power Plants (CHP) are normally based on internal combustion engines. However, emissions from these small engines have been difficult to keep at a reasonable level and the need for service makes the economics of the plants unattractive.
The external combustion of the Stirling engine and the possibility of designing the engine as a hermetically sealed unit with very little need for service has resulted in a project, where a 9 kW Stirling engine for CHP is developed. Two engines have been made and they have been tested in the laboratory through 1999. Results have been very satisfactory, and field tests of the engines with natural gas and biogas as fuel will be initiated in the beginning of 2000.