Enhancing passive cooling of photovoltaic modules using bio-based eutectic phase change materials and barium sulphate radiative cooling paint

The global shift toward renewable energy has intensified the need to improve photovoltaic (PV) efficiency, particularly in tropical climates where elevated temperatures degrade performance. This study evaluates 2 passive cooling methods, bio-based phase change materials (PCMs) and barium sulphate (BaSO₄) radiative cooling paint to mitigate PV overheating. Two eutectic PCM mixtures, lauric acid/oleic acid (LA/OA) and lauric acid/capric acid (LA/CA), were characterized via differential scanning calorimetry, revealing latent heats of 120.1 J/g and 172.1 J/g, respectively. Under simulated solar irradiance of 800 W/m², PCM-integrated panels demonstrated significant thermal regulation, with the LA/CA system reducing peak temperatures by 18.3 °C vs. the reference panel and improving power output by 26.0%. In contrast, radiative cooling paint applied to panel frames or side-mounted heat sinks lowered temperatures by up to 6.1 °C but unexpectedly reduced power generation due to power dissipation, highlighting a trade-off between thermal and electrical performance. The LA/CA PCM emerged as the superior solution for tropical climates, offering sustained cooling and enhanced efficiency, while paint formulations require further optimization to avoid compromising light absorption. This study provides critical insights into passive cooling strategies, emphasizing the importance of holistic performance evaluation for real-world PV applications.