The future of power generation is solar. That’s the view of the International Energy Agency in its new World Energy Outlook report, released in October. The biggest reason: Solar is now cheaper than coal or gas in most of the world. “I see solar becoming the new king of the world’s electricity markets,” said IEA’s executive director Fatih Birol. There’s still a long way to go before that forecast becomes true in the U.S. Last year, utility-scale solar produced just 1.8% of U.S. electricity, according to the Energy Information Administration, despite rapid growth in recent years. The overall portion of power from zero-emission sources, meanwhile, edged up to 38%.

A version of this article appears in the November 2020 issue of Fortune.