Aerosols and Land Constraints Impacting India’s Solar Expansion: IIT Delhi Study

India’s solar photovoltaic (SPV) energy sector has shown remarkable growth in the past two decades, ranking fifth globally in total capacity. However, a recent study by IIT Delhi, titled “India’s photovoltaic potential amidst air pollution and land constraints” published in ‘iScience (Cell Press),’ raises concerns about the sustainability of this expansion.

Research spanning from 2001 to 2018 has revealed a persistent decline in surface insolation (solar radiation) across approximately 90% of India’s land area. This decrease in solar energy availability is primarily attributed to the prevalence of aerosols, atmospheric fine particles and pollutants, rather than cloud cover. The study estimates a dimming trend of -0.29 ± 0.19 Wm-2 y−1, equivalent to an annual reduction in solar resources, posing a threat to India’s solar energy goals.

Currently, only 29.3% of India’s land is suitable for effective SPV harnessing, and this area is diminishing by about 0.21% annually. This decline could result in the loss of 50 GW of solar power generation capacity, equivalent to 75 TWh of electricity. The research suggests that reducing aerosol pollution could potentially open up an additional 8% of land for solar power installations, emphasizing the importance of mitigating aerosol-induced dimming.

The study underscores the need for accurate solar resource assessments considering environmental factors like aerosol pollution and land availability constraints. To ensure sustainable growth in the solar energy sector, India must prioritize strategies to mitigate aerosol impacts on solar irradiance and identify suitable areas for future solar installations.

Key findings include the dominance of aerosols over clouds in modulating solar radiation trends, with 98% of India’s landmass affected by aerosols. While land suitable for photovoltaic generation is mainly found in western and southern India, it is declining annually. Alleviating aerosol-induced dimming is crucial for expediting India’s solar energy expansion and achieving renewable energy targets.