As the Covid-19 shutdowns and stay-at-home orders brought much of the world’s travel and commerce to a standstill, people around the world started noticing clearer skies as a result of lower levels of air pollution. Now, researchers have been able to demonstrate that those clearer skies had a measurable impact on the output from solar photovoltaic panels, leading to a more than 8 percent increase in the power output from installations in Delhi.

While such an improved output was not unexpected, the researchers say this is the first study to demonstrate and quantify the impact of the reduced air pollution on solar output. The effect should apply to solar installations worldwide, but would normally be very difficult to measure against a background of natural variations in solar panel output caused by everything from clouds to dust on the panels. The extraordinary conditions triggered by the pandemic, with its sudden cessation of normal activities, combined with high-quality air-pollution data from one of the world’s smoggiest cities, afforded the opportunity to harness data from an unprecedented, unplanned natural experiment.

The findings are reported today in the journal Joule, in a paper by MIT professor of mechanical engineering Tonio Buonassisi, research scientist Ian Marius Peters, and three others in Singapore and Germany. [click for full article]