Improving heat transfer in solar cells to achieve sustainability and lower greenhouse gas emissions: A comprehensive review

The rapid expansion of solar photovoltaics (PV) as a decarbonization technology has made module performance and sustainability central to global energy planning. Only a small portion of the incident solar spectrum is converted to electricity; the rest is dissipated as heat, which raises cell temperature, depresses voltage, and accelerates long-term degradation. Because the life-cycle greenhouse gas (GHG) intensity of PV electricity is inversely proportional to lifetime generation, improvements in thermal management can substantially lower embodied emissions per kilowatt-hour. This review integrates thermophysical principles with the latest passive and hybrid heat-transfer strategies for PV, including enhanced rear convection and heat spreading, phase-change materials (PCMs), spectrally selective radiative cooling, and hybrid photovoltaic/thermal (PV/T) and PV–thermoelectric (PV–TEG) systems. We critically examine the physics, the governing equations, and real-world performance from both laboratory and field studies. Finally, we explore how heat-transfer improvements translate into better reliability, longer lifetimes, and lower gCO₂-eq/kWh, identifying research gaps in durable coatings, recyclable PCMs, and standardized long-term field data.