Thermo-Economic Comparison of Solar Thermal Cooling and Solar Photovoltaic Cooling Systems for a Typical Residential Building – Lebanese Case Study

This paper aims to investigate the performance of a solar cooling system for a typical residential building in moderate climates. A comparative energy and financial analysis was performed between a solar driven LiBr-H
2
O single effect absorption chiller and solar photovoltaic cooling system. In Lebanon, very few studies have been done on solar thermal cooling and its application. So a typical residential building with a four floors of 100 m
²
each located in Fanar, Lebanon was taken as a case study. After cooling load calculation, simulations on "TRNSYS" and "MATLAB" were conducted to determine performance of the solar thermal cooling system, followed by a Hooke and Jeeves optimization to size it. As for the solar photovoltaic cooling system, "PVsyst" was used to find the optimal equipment sizes covering the cooling load needed. To complete the comparison, a feasibility study and CO
2
emissions’ reduction were calculated for both systems. The results showed that the solar thermal system has a payback period of 7 years 5 months, and saves 16 tons of CO
2
each year. While, the solar PV cooling system has a payback period of 5 years and 1 month and will save 43 tons of CO
2
per year. To summarize, the PV system required to cover the same cooling load takes more space, but it has a better payback time, energy, and CO
2
savings each year. Since Lebanon has a suitable climate for solar energy, such a study provides design guideline on which system is more convenient, while taking the different parameters into consideration.