China’s solar panels would work better with less air pollution Kevin Frayer/Getty Images

Cleaning up China’s hazy skies would increase electricity generation from the country’s vast array of solar panels by 13 per cent and provide billions of dollars of extra revenue, according to a new analysis.

China has more installed solar power capacity than any other country, at 170 gigawatts at the end of 2018. But it also has one of the world’s worst air pollution problems.

In recent years the Chinese government has begun addressing the dangerously dirty air amid health concerns and protests by citizens. Now we know there could be a big economic benefit to the action too, as clearer skies boost the power-generating potential of solar panels.


Bart Sweerts of the Swiss Federal Institute of Technology in Zurich took solar radiation data from 119 stations across China between 1960 and 2015, combining it with data on emissions of sulphur dioxide and black carbon to pinpoint how much human-caused aerosols had dimmed the maximum output from solar panels. He and his colleagues found air pollution had decreased the potential solar generation by 13 per cent over the period.

Lost electricity

In 2016, that would have resulted in 14 terawatt hours less electricity generation, the equivalent of Tunisia’s annual electricity output. By 2030, when China is expected to have increased solar capacity by more than three times the amount it had in 2016, the figure jumps to as much as 74TWh, or the same as Bangladesh’s total generation today.

The extra electricity would have been worth $1.9bn in 2016 and will be worth up to $6.7bn in 2030. “This is many terawatts and many billion of dollars of lost revenue. These are substantial numbers even for a country like China,” says Sweerts.

China has backed deployment of solar at a local level on households and other buildings in cities, but these urban solar panels have been particularly badly hit. Heavily populated regions are heavily-polluting, so dimming is worse here.

The research shows clean air efforts have seen a “minor reversal” of the dimming between 2010 and 2015. But Sweerts cautions: “It is very far from completely clean and very far from the situation in the 1960s.”

Journal reference: Nature Energy, DOI: 10.1038/s41560-019-0412-4