China's scramble to curb pollution has made it the world leader in renewable energy development, yet increasing amounts of that green electricity have gone unused as the country struggles to integrate wind and solar power into an outdated and balkanized electricity network dominated by coal.

The problem threatens to slow China's progress in clearing its air and controlling the greenhouse gas emissions that make it the top contributor to climate change. It also runs counter to a desire by Chinese leaders to fill the leadership gap left by President Donald Trump's move to withdraw the U.S. from the Paris climate accord.

As intern