Combined Heat and Power Generation Systems Design for Residential Houses

Abstract

Nowadays cogeneration is recognized as one of the most effective techniques to meet the increasingly stringent requirements regarding energy efficiency increase and energy saving in buildings. In this context, the aim of this study is the definition of reference parameters for the optimal energy systems design in residential applications. To this purpose, a generation scenario with cogeneration units, heat pumps, auxiliary boilers and chillers (both compression and absorption machines) has been set for the fulfillment of residential users’ needs (in terms of electrical, thermal and cooling loads). For a given number of involved households, commercial cogeneration units have been selected, sized on the basis of the electrical peak need, and the generation scenario has been optimized by an in-house developed software, obtaining the optimal energy systems design and operation. Then, a parametric analysis has been carried out varying the number of considered households in order to define the optimal range of the energy systems size. In particular, specific values in terms of installed power for household and installed power for unitary peak load have been determined. For completeness, an economic analysis has been finally carried out for the evaluation of the return on investment and of the differential net present value – with respect to a standard generation scenario (only natural gas boilers for thermal needs fulfillment and electricity purchase from the grid for electrical and cooling needs) – considering a time horizon of ten years.