Experimental investigation of photovoltaic passive cooling methods using low-cost metallic, ceramic, and cellulose porous media

• Metal pellets, aluminum chips, cellulose pads, and porous SiC ceramic are compared. • Residue wax was used as a low-cost PCM in PV passive cooling. • Metal pellets/PCM exhibited the best techno-economic performance in PV cooling. • Achieved 16.3% temperature drop, efficiency increase of 10.6%, LCOE of $0.134/kWh. • SiC porous ceramic/PCM reduced temperature by 10.9% and boosted efficiency by 7.4%. Maintaining efficient photovoltaic (PV) performance in tropical regions requires addressing the negative impact of high temperatures on cell performance. This study aims to identify the optimal passive cooling configuration for PVs in warm climates through the experimental and economic analysis of four low-cost porous media. Among them, porous silicon-carbide ceramic (SiC) was developed for the first time as porous medium for solar applications. Furthermore, residue wax with a melting temperature of about 40 °C is employed as the phase change material (PCM) due to its favorable availability and cost-effectiveness. The scenarios under study, which include Metal pellets/PCM, SiC porous ceramic/PCM, aluminum shavings/PCM, SiC porous ceramic/water, and cellulose pads/water, were tested and compared against an individual PV panel. According to the technical results, these scenarios demonstrated temperature reductions of 16.3%, 10.9%, 9.3%, 4.2%, and 3.2%, respectively. Additionally, they exhibited average enhancements in electrical efficiency of 10.6%, 7.4%, 5.3%, 3.2%, and 1.3%, respectively. The economic study revealed that the levelized cost of energy (LCOE) for cooling scenarios were $0.134, $0.165, $0.139, $0.155, and $0.166 per kWh, respectively. Accordingly, PCM-based passive cooling methods utilizing either more regularly shaped porosity or micro-porosity, such as metal pellets or SiC porous ceramics, offer superior technical performance. A comparison of results with literature shows that utilizing industrial wastes, including metal pellets, aluminum shavings, and residue wax, has the potential to improve system affordability. It also offers competitive technical performance compared to conventional passive cooling methods, contributing to the sustainable development of PV cooling techniques.