Climate Change Will Increase High Temperature Risks, Degradation, and Costs of Rooftop Photovoltaics Globally

Driven by the global energy transition, solar photovoltaic (PV) investments totaled 500 billion USD in 2024 and could quadruple by 2030. Solar PV panels, particularly rooftop PV, have reduced performance, reliability, and lifespans at high operational temperatures. Existing standards around high temperature risk (HTR) for PV panels are set using historic climate data. Here we show that climate change will increase HTR and resulting PV degradation and costs for rooftop PV globally. We combine bias-corrected output from an ensemble of global climate models with a bottom-up PV physical-chemical Arrhenius degradation and economic model. For PV mounted on tilted roofs, global rooftop PV capacity exposure to HTR will increase by 29% and 97% at 2°C to 4°C global warming relative to the historical period, respectively. Regions with large expected PV growth, including Southeast Asia and North America, emerge as new HTR hotspots. Warming-induced increases in HTR accelerate PV aging and degradation, increasing the levelized cost of electricity (LCOE) for rooftop PV up to 20% globally at 2.5°C warming. These changes will exacerbate regional inequities in rooftop PV reliability and cost, further disadvantaging vulnerable regions in accessing reliable, affordable, and low-carbon energy. Via sensitivity analysis, we find qualitatively similar insights from climate change for alternative PV technologies and for PV mounted on flat roofs. Accelerated degradation and LCOE increases are more modest for PV mounted on flat roofs, of up to 9% globally at 2.5°C warming. Our results underscore the need to update solar PV standards for climate change to safeguard the global energy transition.