Study projects loss in India's solar power potential due to air pollution

India's capacity to generate solar power could fall by 600-800 gigawatt-hour before mid-century due to air pollution and climate change, a study has projected.

The researchers from the Indian Institute of Technology (IIT), Delhi, found that northern, western and southern power grids -- where most solar parks are currently located -- will experience significant challenges in maintaining performance due to climate change.

Pollutants in the air can absorb and scatter sunlight, thereby lowering the intensity of the sun's radiation reaching the earth's surface.

Further, generating solar power relies heavily on weather and climate, and is, therefore, vulnerable to the effects of climate change.

The findings, published in the journal Environmental Research Letters, "highlight the need for combined climate and pollution mitigation efforts to boost India's photovoltaic potential and secure a sustainable, resilient energy future".

Despite being endowed with abundant solar resources -- India receives nearly 300 clear-sky days every year -- the country has seen a persistent decline in incoming solar radiation, a phenomenon known as 'dimming', the authors said.

Using global climate models, the team projected the country's solar power potential by mid-century (2041-2050) under two scenarios -- one with moderate air pollution and climate change, and the other in which climate change is weakly tackled and air pollution strongly controlled.

The results of the analysis suggested that the national average potential for generating solar power could fall by two to nearly four per cent, compared to that during 1985-2014, mainly due to a reduced radiation and increased temperatures.

Further, temperatures of solar cells could be expected to rise by 1.5-2 degrees Celsius, resulting in efficiency losses and an additional of about 18 days of efficiency de-rating, especially in solar-rich regions.

Based on data of solar power generated during 2023-24, loss in generation capacity was projected to range from 600 gigawatt-hours, under moderately controlled air pollution and climate change, to up to 840 gigawatt-hours, under a weak climate action with strong air pollution control, according to the study.

Solar cells -- used in making solar panels and for converting sunlight into electricity -- would need to be innovated for future assessments looking into India's solar power potential, the team said.

They called for robust measures for controlling air pollution and urgent climate action to mitigate losses in generating solar power.

Further, rapidly transitioning to renewable energy is crucial to mitigating both air pollution and climate change, the authors said.