What determines future changes in photovoltaic potential over East Asia?

Heavily industrialized East Asia, with its high greenhouse gas emissions, must inevitably increase renewable energy production to achieve the goals of the Paris Agreement. Photovoltaics (PV), a widely utilized renewable energy source, is directly affected by the weather and climate. This study conducted the first analysis of current and future PV potential (PVpot) changes over East Asia using the ERA5 reanalysis and multiple high-resolution regional climate model simulations. The recent PVpot over East Asia did not exhibit any notable changes, but the future PVpot of the multi-model ensemble is predicted to decrease by −4.3% (winter) to −1.5% (summer) on average with excellent inter-model agreements. Results demonstrated that the widespread increase in near-surface air temperature causes the overall PVpot decrease (around −2.0%) over East Asia across all seasons. Interestingly, surface down-welling shortwave radiation increases in summer, offsetting temperature-induced PVpot decreases (by about 0.7%) while it declines in winter and spring, intensifying the warming-driven PVpot decrease (by approximately −1.4% to −2.3%). Further, the changes in the number of rainy days are associated with the changing patterns of surface down-welling shortwave radiation, indicating the importance of reliable projections of precipitation. Wind speed exerts a negligible effect on the future PVpot change.