A review of the effects of photovoltaic (PV) systems on thermal conditions in the built environment

The thermal effect of photovoltaic (PV) systems on the built environment is an ongoing research field. An up-to-date review integrating indoor and outdoor effects as well as their influencing factors within a unified framework remains lacking. Therefore, this paper presents a literature review on the thermal effects of PV systems based on heat-transfer mechanisms, covering evidence from both experimental and simulation-based evaluation methods. This review aims to identify research gaps and support decision-making in this growing research field; hence, it examined 181 publications from 2003 to 2026. The findings show the potential of PV systems to improve indoor and outdoor thermal conditions, with more pronounced cooling effects observed indoors during summer daytime. Roof PV systems have more significant indoor thermal effects, whereas façade and window PV systems exert more direct effects on outdoor thermal conditions at the pedestrian level. Thermal effects vary with contextual factors, including diurnal and seasonal cycles, climatic conditions and urban morphology, and design factors related to PV modules, PV systems, and the building surfaces to which they are attached. These factors alter the heat-balance components of absorbed solar irradiance, electricity generation, convection, long-wave radiation, and conduction, resulting in different thermal effects under case-specific conditions. Future research should prioritize annual measurements across diverse climates, meso-scale experimental studies, and integration with machine learning.