Synergistic solar photovoltaic and electrodialysis desalination system with waste heat management: A multiscale modeling

Electrodialysis is fascinating for seawater desalination to overcome freshwater crisis. Meanwhile, solar photovoltaics are promising for directly converting solar energy into electricity to reduce fossil fuel consumption. However, when surface temperature of solar photovoltaics is excessively high, their photoelectric conversion efficiency sharply drops down. Facing these challenges, we propose a synergistic solar photovoltaic and electrodialysis desalination system with waste heat management. When waste heat generated from solar photovoltaics is transferred into seawater for electrodialysis, their photoelectric energy conversion and desalination efficiencies are synergistically enhanced. Furthermore, a three-layer serpentine flow channel is designed to cool down solar photovoltaics using seawater. Consequently, the maximum temperature drop of solar photovoltaics is 45.5 degrees C by 52.3 % in comparison to that of solar photovoltaics under natural cooling, and its corresponding electric power generation is increased by 13,828 W about 145.5 % under one sun solar irradiation. Based on multiscale modeling, when waste heat from solar photovoltaics is used to raise seawater temperature from 25 degrees C to 34.6 degrees C, the seawater desalination rate of electrodialysis using ion exchange membrane with 1.0 nm nanopores is enhanced from 62 % to 72.6 %. The current work paves a potential route for developing solar photovoltaic assisted electrodialysis system for efficient seawater desalination.