All-day working photovoltaic cooling system for simultaneous generation of water and electricity by latent heat recycling

The photovoltaic (PV) cooling system based on solar-driven interfacial water evaporation (SIWE) system can effectively reduce the temperature of PV panels and obtain fresh water, but it cannot work at night during which there is no heat source input. In this work, we proposed a novel SIWE-based PV cooling systems with optimized performance that can achieve all-day working. In this hybrid system, the heat generated by the PV panel is extracted as the form of vaporization latent heat through membrane distillation (MD). Then it transferred along with the condensation of water vapor and stored in Phase Change Material (PCM), which is used to achieve electric power generation by thermoelectric effect at night. The hybrid system can achieve an 19.5 % improvement of output power compared with that without cooling method. Additionally, a 1.55 kg m(-2) h(-1) fresh water output with a salt rejection rate more than 99.9 % are realized under 3-sun irradiation. At the same time, it can also achieve a peak power output of 6 W m(-2) at night by the release of latent heat stored in PCM. This hybrid system may provide a new idea to broaden application scenarios of traditional SIWE-based PV cooling systems.