All‐Polymer Polyethylene‐Hydrogel Felt for Efficient Evaporative Cooling and Ecological Restoration in Photovoltaic Power Plants

With the explosive growth of photovoltaic (PV) power station, the energy efficiency and ecological impact of which have emerged as two important points of great concern. In this work, an approach is proposed to cool solar panels and facilitate ecological restoration by engineering moisture cycle in PV plants with an all-polymer hydroscopic felt. Formed by fibers with highly oriented polyethylene (PE) micro-fiber cores and polyacrylamide (PAAm) shells of a few microns in thickness, the felt is ultra-light, anti-corrosive, and demonstrates a high passive heat transfer coefficient of 1100 W m^-2 K^-1. Under the solar light of one sun, the felt reduces the temperature of solar cells by 28 °C, and increases the output power by 20.4%. Moreover, the felt regenerates to the original state in only 1.3 times the evaporation time. In addition, due to the high evaporation and moisture absorption rate, the PE/hydrogel felt exhibits the ability to raise the ambient humidity in photovoltaic plants by 24% and lower the ambient temperature by 2.6 °C, which significantly promotes the survival rate of surrounding flora. These results show the ability of the all-polymer hydroscopic felt in promoting energy efficiency of PV conversion and offers the potential to augment ecological restoration using PV plants.