Photovoltaic power response to El Niño–Southern Oscillation

Photovoltaic energy is expected to lead renewable energy growth, but rising solar energy penetration increases vulnerability to climate-driven intermittency. Here, we examine how the El Niño-Southern Oscillation, the dominant source of seasonal-to-interannual climate variability, affects photovoltaic power output. Using four decades of reanalysis data, we show that El Niño events reduce surface solar irradiance, causing sustained solar energy deficits in regions with growing solar energy penetration, including California, the southern Atacama Desert, the Chaco Basin, the Middle East, and East China. These impacts are especially pronounced during rare Super El Niño events, of which only three have occurred since the early 1980s. Our analysis indicates that future Super El Niño events could significantly lower photovoltaic generation, increase reliance on fossil fuel backup, and temporarily raise carbon dioxide emissions by tens of millions of tons.