Thermal management of photovoltaic systems using cascade phase change material module

The phase change material (PCM) cooling technology has been recognized as one of the effective methods for reducing the operating temperature of photovoltaic (PV) cells and enhancing photoelectric conversion efficiency (PCE). However, the issue of slow thermal response in traditional phase change modules has posed a significant barrier to their large-scale application. To address this, a heat transfer-storage model for PV was established to investigate their temperature characteristics and thermal generation properties, based on which a cascade phase change material thermal management module (cas-SCPCM) was proposed. Among them, the PCM was comprised of paraffin (PA), expansion graphite (EG), polyethylene octene co-elastomers (POE), ethylene-ethylene-butadiene-styrene (SEBS), and carbon nanotubes (CNTs), and its thermal control performance was analyzed. The results indicated that during the operation of the PV cells, approximately 50 % of the absorbed solar energy was converted into thermal energy, leading to a temperature increase. Under various irradiance intensities, the cas-SCPCM demonstrated superior thermal control performance compared to traditional single-layer phase change material thermal management modules. At an irradiance intensity of 2000 W/m², the temperature of the cas-SCPCM photovoltaic cell was reduced by 34.6 %, and the PCE was increased by 27.1 %. Compared with the traditional phase change modules, the cas-SCPCM enables PV to exhibit better electrical output performance, providing valuable guidance for low-energy PV building integration.