Techno-Economic Analysis of Solar Cooling Systems for Residential Buildings in Italy

Solar cooling systems might represent a viable alternative for space cooling in residential buildings because the peak of cooling demand matches the availability of solar radiation. The use of adsorption chillers in this field gives another environmental benefit, since they employ natural refrigerants as water. However, the design of such systems is critical because it relates to several parameters and cannot be easily accomplished using traditional tools. In this work, a dynamic model for the simulation of a small solar cooling system employing adsorption chillers has been evaluated. The model, realized with the commercial software TRNSYS, has been implemented to quantify the effect of different operational and design parameters on the overall performances of solar cooling systems in three different Italian cities (Milan, Rome, and Messina). Particular focus was put on the comparison of different heat rejection systems, which was found to be a critical aspect in the design of such systems. In addition, an economic analysis has been performed for an optimized system, in order to evaluate the payback time of the systems compared to a traditional air conditioning system and provide indication on the possible outlooks by means of a sensitivity analysis.