Exergy Analysis of Solar Energy Systems for Residential Buildings

Abstract

In order to reduce fossil-fuel consumption to cope with global warming, solar energy use technologies become increasingly important in recent years. This paper presents the result of a comparative evaluation of the solar water heater and the photovoltaic power generation system installed on the roof of a detached house. The evaluation was conducted based on "exergy" as an index to express the qualitative difference between electric power and thermal energy. The results of this study showed that the energy efficiency of the photovoltaic power generation system is lower than that of the solar water heater, whereas the exergy efficiency of the photovoltaic power generation system is higher than that of the solar water heater.