A team from the Indian Institute of Technology (IIT) team pointed out, a common hope is that through solar energy, energy transition will be smooth and eventually net zero carbon emissions will be achieved. However, if air pollution is too serious, no matter how many solar panels are installed, the effect will be greatly reduced. Thus, India has squandered 29% of its solar energy development potential.
Sagnik Dey, associate professor of atmospheric sciences at the Indian Institute of Technology, said that the main reason why air pollution reduces solar power generation is because aerosols absorb and scatter light. According to the team's research, between 2001 and 2018, India's solar energy potential dropped by 29% due to air pollution, which is equivalent to an annual loss of US$835 million.
Dey pointed out that aerosols such as dust, particles, mist, and fumigation in the air can significantly reduce the amount of solar radiation, which is also known as the atmospheric attenuation effect. Usually, when conducting large-scale solar development projects, developers have this in mind but some manufacturers do not take into account the "pollution impact" of aerosol deposition on solar panels.
India is currently surging solar installations but according to research center Mercom India, as of March this year, India's solar installation capacity is only half of its target, at only 50GW. He believes that air pollution in South Asia is becoming more and more serious and the two problems above must be solved in order to improve the profitability of solar energy systems
According to past research, in areas with severe air pollution, due to dirty solar panels and reduced chance of rainfall, suspended particles can reduce solar power generation by more than 50%. Bhupendra Das, an environmental researcher at Tribhuvan University in Nepal, also pointed out that acid rain can corrode solar equipment and brackets, driving up maintenance costs.
The team believes that the solution at this stage is to find the optimal tilt angle to install a solar panel. Compared with a horizontally installed module, dust is less likely to accumulate or get stuck and it can also be converted into a more expensive sun tracking system. In the long run, it may still have to rely on India's air pollution prevention and control plan. For example, India launched the National Clean Air Programme in 2019. The goal is to use 2017 as the benchmark and reduce PM 2.5 concentration by 20%~ 30% in 2024.
Otherwise, according to the "2021 Global Air Quality Report" released by IQAir, a Swiss air quality technology company, the most polluted capital in the world is New Delhi, India. Its average PM2.5 concentration ranked first and 34 other cities in India were also ranked among the most polluted cities in the world.
（Image：Flickr/oatsy40 CC BY 2.0）
