Analysis of electric and thermal seasonal performances of a residential microCHP unit

Abstract One of the most recent innovation of thermo technique industry is the development of wall hung cogenerative gas boilers that adopt Stirling engines in combination with condensing heat exchangers. Such machines are suitable for installation in single houses since the electric power is around 1 kW. However in order to justify the investments on the electric grids and to urge the simplification in laws, that makes now very difficult the installation, it is important to be able to quantify the primary energy savings achievable with such technologies; moreover because of the higher cost for the user it is also necessary to quantify the savings of money. For those reasons the aim of this work is the calculation of the energetic and economic performances of a Stirling engine microCHP installed in a detached house, built in 70’s in Milan in comparison with a condensing gas boiler as reference case. The simulations carried out using TRNSYS software show that the use of the Stirling microCHP gives advantages both in energetic and in economic terms, but they shown also that those advantages are higher with some schedules of the heating.