Cascade Use and Optimal Control of Solar Thermal Energy for Hybrid Solar Energy System
Abstract
Solar energy is a promising technology for reduction of CO2 emission with amenity of life. The use of solar energy is divided to two methods: electricity conversion and thermal energy conversion. In this paper, the authors describe about the combination use of photovoltaic and solar heat collector. The authors investigated the effect of operating condition of hybrid solar energy system on energy saving potential in Japan. Thermal output from the heat exchanger was 26.1% of total demand of room heating. The low supply point decreased the effect of reduction of room heating to 66%. The additional thermal energy for hot water supply also decreased. The reduction of room heating demand by hot water will be effective when the heat source of room heating has high environmental load or the efficiency of room heating apparatus is low. The total amount of surplus PV electricity in a day was 4147.0kJ on a holiday and was 2523.4kJ on a working day. The use of surplus electricity for hot water supply is effective for reduction of electricity in the evening.