Coal plants persist as a large barrier to the global solar energy transition
2026-05-15
The global energy transition depends on solar photovoltaic (PV) power displacing fossil fuels to deliver projected climate and air quality benefits. However, aerosol pollution from co-located coal plants actively suppresses PV energy production. Here a global, facility-level dataset shows that aerosols reduced global PV generation by 5.8% in 2023 (111 TWh). From 2017 to 2023, annual aerosol-induced PV energy losses from existing systems were, on average, equivalent to one-third of the energy added by new PV installations. In China, aerosols caused the largest PV energy losses worldwide, reducing national PV generation by 7.7% in 2023. The corresponding annual loss-to-growth ratio averaged 38% and frequently exceeded 50%. Despite continued coal expansion, PV energy losses have declined by 1.4% yr −1 since 2017 owing to stricter emission controls. By contrast, the USA, where co-location of solar and coal plants is limited, experienced only 3.1% aerosol-induced PV loss. Given the slow pace of global coal phase-out, these results reveal a constraint on solar performance that, if unaccounted for, could lead to a systematic overestimation of the transition’s contribution to climate and air quality goals.