Hydropower Generation by a Self-Circulating Solar Thermosyphon

A self-circulating solar thermosyphon (TS) was applied to hydropower generation for the first time. A TS consists of a solar thermal collector, condenser, buffer chamber, hydropower section, heat exchanger, and recuperator. In the present study, the power output level was 10⁻⁶ W for the solar irradiation input of 10² – 10³ W. The coefficient is 10⁻⁹. Considering the Carnot’s coefficient, 0.13, for the heat source and sink of temperatures 70°C and 25°C, there is room for remarkable improvement in TS hydropower generation. Moreover, the solar thermosyphon hydropower generation may provide us with new ways of utilizing heat below a temperature of 100°C, which until now has been merely used for things such as hot water supply and floor heating.