• A research team of MIT along with Cleantech Energy Corp. says urban-based solar installations must take into account the impact of haze to ascertain expected solar power generation
  • The study found substantial loss of power generation due to haze in several densely populated cities around the world, with output loss being the highest in Delhi, about 12% annually
  • In the absence of such an assessment for a prospective solar power installation, haze may unexpectedly turn a solar investment into loss making venture
  • In case of Delhi, haze could mean annual loss of solar revenues in the range of $20 million, while forBeijing and Shanghai, it could be $10 million
  • The impact of haze on cell technologies varies, with standard silicon performing best and perovskite worst

Consistent levels of air pollution in India’s capital Delhi brings down annual average level of solar panel output by about 12%. Pollution levels in Delhi where ‘there’s never a day without pollution’ was the subject of a research by the Massachusetts Institute of Technology (MIT) that tried to quantify how haze created by pollution in densely populated cities impacts urban-based solar installations.

The research claims the impact is substantial leading to installations that operate at a loss failing to meet expected production levels. They tried to assess how much sunlight was actually being absorbed or scattered by haze before it touches the solar panels.

The research team, comprising Andre Nobre from Cleantech Energy Corp., MIT Associate Professor of Mechanical Engineering Tonio Buonassisi and three more members, examined preliminary data from 16 other cities around the world, beyond Delhi and found impacts ranged between 2% for Singapore to over 9% for Beijing, Dhaka, Ulan Bator and Kolkata. Delhi showed annual average attenuation levels of solar output to be about 12%.

An amount at this level is big enough to impact profit margins and lead to a plant’s economic success or failure. A ripple effect from such a project can also act as a deterrent for others from investing in solar projects. Hence, the research suggests factoring in the impact of haze while calculating the expected levels of sunlight reaching the ground in that area before setting up a solar power plant.

Additionally, the team assessed the impact of such a haze for various types of solar cells, including gallium arsenide, cadmium telluride and perovskite. All of them were affected more strongly than standard silicon panels studied for the project, while perovskite suffered the most with over 17% attenuation in Delhi.

The study, published in the journal Energy & Environmental Science, claims lost revenue from power generation in Delhi alone could amount to as much as $20 million annually, while for Beijing and Shanghai, it could be $10 million. Even Los Angeles could lose $6 to $9 million annually for the same reason.

India aims to generate 40 GW of rooftop solar power capacity by 2022. Delhi Solar Policy has set a target of 2 GW of solar power by 2025 (see Delhi Solar Policy).

A study by the University of Texas, Austin in the US, published in August 2018 in Environmental Science & Technology Letters, claims the lifespan of an average Indian is decreased by over 1.5 years due to ambient air pollution.

The research was supported by Singapore’s National Research Foundation through the Singapore-MIT Alliance for Research and Technology and by the US Department of Energy and National Science Foundation.