Improving the Characteristics of Phase Change Material for Use in Cooling Bifacial Solar Panels: a Preliminary Study
Abstract
Effective passive cooling is critical for sustaining the performance and transparency of bifacial photovoltaic modules. This study evaluated three key properties of phase change materials (PCMs) for such applications: degree of supercooling, transmissivity and thermal conductivity. To enhance these properties, three different nucleating agents, zinc oxide (ZnO), graphite and titanium dioxide (TiO 2 ), were added at different concentrations. ZnO at 0.1 wt% was found to be the best overall, reducing supercooling from 18.5 °C to 2.5 °C, improving conductivity by 37%, and maintaining high transmissivity (91.1% in liquid state). Graphite was most effective at enhancing heat transfer, with a 146% increase at 0.5 wt%, but decreased transmissivity by 96.6%. TiO₂, meanwhile, yielded little thermal benefit and decreased light transmission. This work points to ZnO as the most promising additive for enabling transparent PCM cooling in bifacial modules, leading the way for a cost-effective method to enhance bifacial performance and longevity.
Keywords
bifacial photovoltaic, phase change material, supercooling, thermal conductivity, transmissivity