Extended lockdown measures to curb the spread of COVID-19 in the world has helped clear the air, bringing down massive pollution levels across the globe. In what is infamous as one of the most polluted cities globally, Delhi, a study observed that clearer air allowed more sunlight to pass through the atmosphere leading to solar PV panels installed here increasing their output.
With no polluting vehicles on the roads and practically all economic activity coming to a standstill between late March 2020 and May 2020 when there were massive restrictions placed on non-essential movement, researchers at the Helmholtz-Institut Erlangen-Nurnberg for Renewable Energies (HI ERN) in Germany found that in late March 2020 the amount of sunlight reaching solar panels in Delhi went up by some 8% compared to data of the previous 3 years, 2017 to 2019.
The researchers analyzed a PV installation in Paschim Vihar in Delhi and found that the solar system between March 2020 and April 2020 received more than 6% higher sunlight levels than in previous years. Their findings suggest that the drop in air pollution is the 'root cause' for the observed increase in insolation and are consistent with previous instances of low air pollution.
"The increase that we saw is equivalent to the difference between what a PV installation in Houston would produce compared with one in Toronto," said Ian Marius Peters, lead author of the study that has now been published in the scientific journal Joule with the title The Impact of COVID-19 related Measures on the Solar Resource in Areas with High Levels of Air Pollution.
Peters added, "We've gotten a glimpse of what a world with better air looks like and see that there may be an opportunity to 'flatten the climate curve'. I believe solar panels can play an important role, and that going forward having more PV installations could help drive a positive feedback loop that will result in clearer and cleaner skies."
A Massachusetts Institute of Technology (MIT) study in 2018 found air pollution and resultant haze in Delhi to pulling down annual average level of solar panel output by about 12% (see Delhi Pollution Brings Down Solar Panel Output).