COVID-19 lockdown measures brought most of the world’s commerce and travel to a standstill. The air pollution dropped dramatically as a result. Several news reports showed how much the air quality improved, especially in parts of the world with pollution problems such as China, Italy, India, and the United States. However, clear skies aren’t the only good thing that came of reducing air pollution levels.
A team of researchers just demonstrated how the clarity in the atmosphere results in a substantial increase in the output of electricity from solar photovoltaic installations. The study is based in Delhi, one of the planet’s smoggiest cities. When the air cleared after coronavirus shutdowns, the solar installations there produced 8.3% more power than usual in March and 5.9% more in April.
Study co-author Ian Marius Peters, an MIT research scientist, said:
These deviations are much larger than the typical variations we have within a year or from year to year— three to four times greater. So we can’t explain this with just fluctuations. The amount of difference is roughly the difference between the expected performance of a solar panel in Houston versus one in Toronto.
Study author Tonio Buonassisi, an MIT professor of mechanical engineering, added:
An 8 percent increase in output might not sound like much, but the margins of profit are very small for these businesses. If a solar company was expecting to get a 2 percent profit margin out of their expected 100 percent panel output, and suddenly they are getting 108 percent output, that means their margin has increased fivefold, from 2 percent to 10 percent, he points out.
The extraordinary conditions triggered by the pandemic made it possible for the team to conduct this first-ever study demonstrating and quantifying the impact of reduced air pollution on solar output.
The team has been researching the effects of air quality and unusual weather patterns on solar panels since 2013. This study was an extension of that. They combined what data they already had along with high-quality, years-long record of fine particulate air pollution (P2.5) measurements that had been collected every hour, year after year, by the U.S. Embassy in Delhi.
They compared the embassy’s air pollution data, meteorological data on cloudiness, and the solar irradiation data from the sensors to determine the actual effects of pollution on solar panel output. From this analysis, they identified an approximate 10% overall reduction in production due to pollution, which is enough to affect the facilities’ financial projections negatively.
Buonassisi said:
The findings provide real data on what can happen in the future as emissions are reduced globally. This is the first real quantitative evaluation where you almost have a switch that you can turn on and off for air pollution, and you can see the effect. You have an opportunity to baseline these models with and without air pollution. By doing so, it gives a glimpse into a world with significantly less air pollution.
The study also shows how by increasing the usage of solar electricity overall, it makes the panels more efficient. Displacing fossil-fuel generation that produces air pollution makes all solar panels work better.
Buonassisi continued:
Putting solar panels on one’s house is helping not only yourself, not only putting money in your pocket, but it’s also helping everybody else out there who already has solar panels installed, as well as everyone else who will install them over the next 20 years. In a way, a rising tide of solar panels raises all solar panels.
In this study, the focus was on Delhi because the effects there are so easy to detect. However, the results stand true worldwide, wherever there is air pollution – if you reduce it, there will be beneficial consequences for solar panels, Peters concluded.
