Climate change factors could affect India’s solar potential

India has set ambitious solar energy targets to meet its climate commitments. However, climate change, already evident in the country, poses significant challenges to solar power generation, according to a new study published in Environmental Research Letters and as highlighted in a Mongabay-India (MI) report. As the MI report points out, with plans to install 100 GW of solar energy by 2030, India has positioned solar energy at the centre of its strategy to mitigate climate change. However, changing weather and high pollution will reduce the efficacy of solar photovoltaics (SPV) in the future, according to the study.

Researchers from the Centre for Atmospheric Sciences, Indian Institute of Technology (IIT) Delhi used radiation data from global climate models available to analyse the twin impacts of climate change and air pollution on SPV performance.

The study, using data from 1985 to 2014 as a baseline to predict a change from 2041 to 2050, concludes that SPV’s efficacy may decrease by 3.3% by the middle of the century. Based on current solar power production levels, the study estimates a loss of 600 to 840 gigawatt-hours (GWh) of electricity annually. PV power generation at a specific location is determined by the nominal installed PV capacity and the PV potential at that site. The potential depends on the availability of solar radiation and other factors such as ambient temperature, surface winds, and humidity.

As the Introduction to the study states, the global expansion of solar energy plays a vital role in mitigating climate change and fostering a cleaner, more sustainable future. India currently ranked fifth in the world, contributes approximately seven per cent of the global solar capacity. The nation has committed to reducing the emissions intensity of its gross domestic product (GDP) by 45% by 2030, compared to 2005 levels. Additionally, India aims to achieve around 50% of its cumulative electric power installed capacity from non-fossil fuel sources by 2030. This objective translates to roughly 500 GW of renewable energy capacity, with a significant proportion from solar power. Key initiatives to achieve this include reaching 100 GW solar target, expanding solar parks, and promoting rooftop solar installations.

According to the paper and as per the MI report, India gets around 215 solar-rich days per year when the incoming solar radiation exceeds 208 watts per square metre, which is considered necessary for PV generation. Southern, western, and northern power grids receive more such days than the eastern and northeastern grids. However, weak air pollution controls could reduce this by up to 15 days per year, while medium efforts may limit the reduction to about eight days. Irrespective of which meteorological factor plays a more significant role, a declining trend of solar radiation is projected for most of the country during 2041-2050.

The study further highlights that however, like most renewable energy sources, solar power generation is heavily dependent on weather and climate, making it vulnerable to the impacts of climate change. India is endowed with abundant solar resources, receiving 300 clear-sky days annually and high surface solar irradiance. Nevertheless, the country has experienced a persistent decline in incoming solar radiation, a phenomenon known as ‘dimming’. Unlike many other regions, India has not observed a clear increase in solar radiation, or ‘brightening’, suggesting a significant influence of anthropogenic aerosols. The long-term variations in solar radiation, coupled with the significant aerosol burden and the rapid expansion of solar energy infrastructure, underscore the need to investigate future changes in surface solar irradiance and the potential for SPV energy in India. This depends not only on surface solar irradiance but also on factors like ambient temperature, surface winds, and humidity. These factors influence the efficiency of PV modules and, consequently, the overall performance of PV systems. The findings suggest that changes in solar radiation will be the primary driver of PV potential decline across India, with rising temperatures further exacerbating this downward trend.

As the MI report states, India plans to achieve 500 GW of non-fossil-based electricity generation capacity by 2030. Of this, 100 GW is expected to be solar. It is, therefore, essential to address efficiency losses that may hamper its PV potential in the future.