Persistent Extreme Surface Solar Radiation and Its Implications on Solar Photovoltaics

Climatic extreme events are important because they can strongly impact humans, infrastructure, and biodiversity and will be affected by a changing climate. Surface Solar Radiation (SSR) is the primary energy source for solar photovoltaics (PV), which will be indispensable in future zero-emissions energy systems. Despite their pivotal role, extreme events in SSR remain under-documented. We provide a starting point in extreme SSR analysis by focusing on events caused by internal variability alone and therefore building a baseline for future extreme SSR research. We analyze extreme SSR events using daily-mean data from the pre-industrial control simulations (piControl) of the Coupled Model Intercomparison Project—Phase 6. We investigate their role in PV energy generation using the Global Solar Energy Estimator with the intent of strengthening the energy system's resilience. Our results show a pronounced asymmetry between consecutive days with extremely high and extremely low solar radiation over land, the former occurring more frequently than the latter. Moreover, our results call for detailed PV generation modeling that includes panel geometry. Simple models based on linear SSR representations prove insufficient due to pronounced seasonal variations and strong non-linear SSR dependency of high extremes. Our results demonstrate how climate model results can be leveraged to understand persistent radiation extremes that are relevant for future energy systems.