Effective integrated thermal management using hygroscopic hydrogel for photovoltaic-thermoelectric applications
H.Z. Wu, Shangzhen Xie, Guopeng Chen, Congji Zhang, Kang Xiang, Zhiguang Guo
Abstract
As the proportion of solar energy in the global energy mix increases, photovoltaic cells have emerged as one of the fastest-growing technologies in the renewable energy sector. However, photovoltaics utilize only a limited portion of the incident solar spectrum, resulting in significant amounts of light energy being wasted as heat. This excess heat raises the surface temperature of photovoltaic cells, which in turn reduces their overall efficiency. To address this issue, it is essential to implement effective cooling methods to enhance the power generation efficiency of photovoltaic systems. This paper proposes an integrated thermal management system combining a hygroscopic hydrogel with a thermoelectric generator (TEG). Under a light intensity of 1 kW/m 2 , the cooling strategy achieved a reduction in surface temperature of 11.9 °C, delivering a cooling power of 136 W/m 2 . This cooling power significantly exceeds the conventional radiation cooling power range of 40–120 W/m 2 . Furthermore, at a light intensity of 1.2 kW/m 2 , the waste heat generated by the photovoltaic cells can be harnessed by the TEG to produce an additional voltage output of 0.15 V. Additionally, the hygroscopic hydrogel used in the system can be regenerated through the absorption of water molecules from the atmosphere following evaporation. The superior performance of this proposed integrated photovoltaic cooling system not only improves the efficiency of photovoltaic systems but also enhances their energy conversion capabilities. Consequently, this system offers a novel approach to thermal management in photovoltaic technology.