Air Pollution Cut India’s Solar Power Output by 9.6% in 2023, Nature Sustainability Study Finds

A new analysis published in Nature Sustainability has found that aerosols in the atmosphere reduced India’s solar power output by 9.6 per cent in 2023 — equivalent to about 15 terawatt-hours (TWh) of lost generation. The global average loss due to the same cause in 2023 was 5.8 per cent, making India one of the worst-affected major economies, with the highest losses concentrated in its heavily polluted north.

The researchers built what they describe as the first global facility-level database of solar photovoltaic generation and aerosol-driven losses, covering about 1.4 lakh solar installations worldwide. They combined this database with satellite observations, atmospheric data and machine-learning. Between 2017 and 2023, the study estimates that pollution-related electricity-generation losses from existing solar installations averaged about 74 TWh a year — roughly one-third of the new electricity that India added every year through fresh solar capacity.

Aerosols include fine particles of sulphates and carbon. Major human sources of these particles include coal-based power plants, road transport, biomass burning, construction dust and industrial emissions. Smog, which is a mix of aerosols and gases, directly reduces the amount of sunlight reaching solar panels and undermines their efficiency, weakening one of the main tools meant to replace coal in India’s electricity mix. China lost the largest absolute amount of generation in 2023 (61.3 TWh), but its loss as a fraction of total generation was lower at 7.7 per cent.

For exam aspirants, the study links environmental policy (air quality standards under NAAQS, the National Clean Air Programme), energy policy (India’s NDC of 500 GW non-fossil capacity by 2030), and the science of solar PV — showing how environmental and energy transitions are coupled rather than independent.