Technological watch

The solar energy spectrum absorbed and converted by PV modules is mainly located in the high-frequency band (380–1200 nm), while the spectral energy in other bands that fail to generate electricity is converted to heat and dissipated into the environment, which leads to lower energy utilization efficiency. Spectral beam splitting cascade utilization is a potential technology to improve the efficiency of solar energy utilization. In this paper, a novel combined cooling, heating and power system with solar energy spectral beam splitting was developed according to matching the energy grade and the operating characteristics of refrigeration cycles. The theoretical investigation carried the parameters distribution of energy load and efficiency out. The solar spectrum is divided into the high-frequency spectrum for electric power generation and the low-frequency spectrum for thermal energy harvesting. The spectrum energy after removing electrical power generation is recovered for fluid heating. The part of thermal energy with high temperature is used to drive the ejector refrigeration system to obtain the cooling capacity. Hot water is derived from low temperature thermal energy. Through the effective conversion of energy and heat recovery, the novel system ensures the efficiency of solar energy utilization and realizes a high-efficiency combined supply of cooling, heating and electricity. The total energy utilization efficiency and the total converted generation efficiency of the novel system can reach 82.7 % and 44.9 %, respectively, which is a remarkable improvement from 30.7 % of the conventional single photovoltaic system. The research results provide inspiration for the efficient utilization of solar energy and facilitate the realization of more application scenarios.