New analysis from energy think tank Ember found solar supplied 12.8% of U.S. electricity in May, edging past coal at 12.2%.
The crossover marks a dramatic shift from just five years ago. In May 2021, coal generated nearly one-fifth of the nation's electricity while solar accounted for just 5.4%. Today, solar has more than doubled its share of the power mix as coal's share has nearly been cut in half.
"Solar power, historically, has usually been described as a relatively niche power source that works in some applications, some of the time," said Nicolas Fulghum, a senior data analyst with Ember. "What this shows is it's now directly on the same level or contrasted with coal power."
While the data are national, some of the country's strongest solar markets are in the Mountain West.
Nevada generates roughly one-third of its electricity from solar power, among the highest shares in the nation, according to the Solar Energy Industries Association. Arizona ranks among the country's leading states for installed solar capacity, while New Mexico, Utah and Colorado have all seen rapid solar growth over the past decade.
Fulghum said falling costs have helped drive solar's expansion across the region.
Growing electricity demand is also playing a role. Utilities across the West are preparing for increased power needs from data centers and other large energy users. Solar developers increasingly view solar and battery storage as one of the fastest ways to add new power to the grid.
Analysts say May's crossover reflects a broader trend rather than a seasonal anomaly.
Solar generation increased 17% from a year earlier, while coal generation declined 11%. Solar also became the nation's third-largest source of electricity, behind only natural gas and nuclear power.
Ember expects solar to pull ahead of coal more frequently in the years ahead.
"Solar is likely going to have more and more months where it is higher than coal," Fulghum said. "And then ultimately in two or three years, we do expect it to also overtake coal on an annual basis."
The milestone comes even as the Trump administration has sought to bolster the coal industry through new investments and policy support, including a recent plan to direct nearly $700 million toward coal-related projects.
This story was produced by the Mountain West News Bureau, a collaboration between KUNR, Wyoming Public Media, Nevada Public Radio, Boise State Public Radio in Idaho, KUNC in Northern Colorado, KANW in New Mexico, Colorado Public Radio, KJZZ in Arizona and NPR, with additional support from affiliate newsrooms across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting and Eric and Wendy Schmidt.
