Cooling Strategies for Photovoltaic Modules in High-Temperature Tropical Environments: A Review

Photovoltaic (PV) module performance is significantly constrained by operating temperature rise, particularly in hot and tropical climates where a large portion of incident solar radiation is converted into heat rather than electricity. Experimental and review studies report that PV module temperatures commonly reach 50–60 °C and may approach 80 °C under high ambient conditions, resulting in a power reduction of approximately 0.4–0.5% per °C increase above standard test conditions. This performance degradation is primarily due to temperature-induced reduction in open-circuit voltage and is further associated with accelerated material aging and reliability losses. To address thermal losses, research has increasingly focused on passive and low-energy cooling strategies. These include rear-mounted heat sinks and fins that enhance natural convection, air channels and chimney-based designs that promote buoyancy-driven airflow, and phase change material (PCM) systems that absorb excess heat through latent thermal storage. Recent studies emphasize thermal conductivity enhancement of PCM using fins, metal foams, or structured containers, achieving PV temperature reductions exceeding 20 °C and corresponding efficiency improvements. Water-assisted backside cooling and hybrid systems combining air, conduction, and water mechanisms have also demonstrated short-term gains in electrical output under high solar irradiance. Despite notable progress, key research gaps persist, including the absence of standardized net-energy evaluation frameworks, limited long-term field data linking cooling to degradation reduction, challenges in PCM discharge under hot night conditions, water sustainability concerns, and insufficient emphasis on scalable, low-cost, and retrofit-compatible designs. Addressing these gaps is critical for reliable PV operation in high-temperature environments.