Ranked as the most polluted capital in the world, it’s no surprise that clear skies are a rare commodity in Delhi. That’s why, earlier in April, people living in the Indian capital were pleasantly surprised to find that the nationwide lockdown has not only brought the freshest air the capital has breathed in decades but has also put the sun and the blue back in the skies. The drop in air pollution, however, has provided yet another perk: solar panels were able to produce more power.
“In very polluted cities like Delhi or Shanghai, air pollution reduces the amount of sunlight coming through the atmosphere by about 10 percent,” says Ian Marius Peters, a research scientist at MIT’s Photovoltaics Lab and coauthor of a new paper that looks at the impact of Delhi’s COVID-19 lockdown on solar power output.
According to the new study, together with a 50 percent drop in pollution levels after the shutdown, the total output from solar panels in Delhi increased by 8.3 percent in March, and 5.9 percent in April.
Those percentages may seem small, but they’re significant, especially when it comes to how profitable this renewable energy is. For solar power businesses, the margins of profit are usually very small—about 2 percent, based on a panel that is producing 100 percent of its possible power. Any variation in output, like pollution or cloud cover, will affect how profitable these panels are, explains Peters.
What’s more, this benefit is also a positive feedback loop: If you reduce the amount of air pollution, then solar panels generate even more clean energy which, in turn, helps reduce air pollution even more as renewable power replaces fossil fuels.
And while a continuous lockdown is not a realistic attempt to get rid of air pollution and stave off climate change, the event offers us an opportunity to see what could be possible and what the world could look like if we solved these problems.