Abstract
Aiming at reduction of the energy consumed in domestic use, research of an energy system corresponding to ZEH (Zero Energy House) is advanced. The authors are developing a hybrid heat source Stirling engine CHP (combined heat and power) system, which uses solar and woody biomass for a heat source and supplies power generation and warm water. This paper describes basic characteristics of a solar tracking type collector made by a Fresnel lens. The test results of a basic solar collector with a rectangular concentrating area were presented, and here new test results of an improved solar collector with a circular concentrating area are reported. The latter are improved in an absorbed heat efficiency.