Best practice in residential micro-CHP systems design

The aim of this paper is to evaluate the profitability of micro-CHP systems for the heating of residential buildings. A micro-CHP system is intended as a system composed of a prime mover, a thermal storage system and an auxiliary boiler. For this kind of system analyses were carried out in order to evaluate both profitability and primary energy saving compared to the separate production of electricity and heat. In particular, the analyses provide the operating hours, the produced electric and thermal energy and the allowable marginal cost of the CHP system with respect to a traditional boiler as a function of prime mover technology and size and of the thermal storage system size. Moreover, the relation between the CHP production (operating hours) and the thermal storage system size is evaluated thoroughly, showing its effect on the economic results.