Optimization of Micro-chp Systems in Residential Buildings from an Economic and Energetic Point of View

This paper investigates the optimal configuration of micro combustion engines (kWel or kWth), the associated volume of thermal heat storage and the thermal capacity of an additional boiler (kWth) for heat supply in residential buildings with 30 units, which have been built in Vienna (Austria) during different construction periods (before 1919 to 2011). The target function for the configuration is defined, on the one hand, as the minimization of heat generation costs represented by investment, operational and maintenance costs. On the other hand, a minimization of the embedded energy, represented by the energy for manufacturing and operation of the micro-CHP plants (including the thermal energy storages), is performed. A power performance ratio is derived by the proportion between the thermal power of microCHP plants and the maximum heating load, which also describes the difference between the various performances.