Even as Donald Trump boosts coal over clean energy, solar power is hitting new milestones in the US and remains the leading source of new power.

Data released on Wednesday by the global energy thinktank Ember, along with a report by the Solar Energy Industries Association (Seia) and analytics firm Wood Mackenzie, show the continued growth of solar and decline of coal in the United States despite federal policy. In May, for the first time, solar supplied more of the nation’s electricity than coal, or 12.8%, Ember said. Coal supplied 12.2%, its fourth-lowest monthly share ever.

“For years solar power has risen in the US electricity mix,” said Nicolas Fulghum, senior energy and data analyst at Ember. “At the same time, coal power has lost its status, first as the largest source in the US mix, and then gradually over the years has fallen even further.”

Solar also became the third-largest source of electricity in the US in May, behind natural gas and nuclear, Fulghum said. Coal generation hit an all-time monthly low in April and rebounded only modestly in May, allowing increasing solar generation to overtake coal, he added.

Electricity is produced by converting sources of energy – fossil fuels, renewable resources and nuclear – into electrical power. Burning coal, oil and natural gas for electricity emits carbon dioxide, trapping heat in the atmosphere and warming the planet. By contrast, solar, wind, geothermal, hydropower and nuclear are carbon-free.

After about two decades of essentially flat electricity consumption in the US, electricity demand is increasing to power artificial intelligence, grow domestic manufacturing and electrify transportation and heating. Fulghum said he expected to see more months when solar exceeds coal generation, before overtaking it on an annual basis in a few years.

These milestones signify that solar “has staying power” at a time when there is less support for renewable energy at the federal level, he added.

Wind and solar combined have overtaken coal in the past, and wind power alone has outpaced coal during spring months when wind speeds pick up. Ember gets its hourly and monthly data from the US Energy Information Administration.

Globally, electricity generation from renewables is growing rapidly. Renewables will become the largest global energy source, used for almost 45% of electricity generation by 2030, according to the International Energy Agency.

Last week, Trump, a Republican, announced a plan to boost the struggling US coal industry by spending nearly $700m to support coal-fired power plants and coal exports. Trump said at a White House event that “coal’s a great business” and that “in terms of power, there’s really nothing like it”.

Martin Pochtaruk, CEO and founder of Canadian-based solar panel manufacturer Heliene, said Trump can say that coal is coming back but investors will invest their money in whatever brings the best return. And for power generation that is solar, making it the fastest-growing fuel, he added.

A White House spokeswoman defended the Trump administration’s overall energy policies, saying they were geared toward strengthening the country’s security.

“The President has reversed the Left’s devastating policies, saved the American coal industry, prevented the retirement of more than 17 gigawatts of power, and saved lives during heightened demand periods,” Taylor Rogers said in a statement.

While Trump is trying to reverse the coal industry’s decline, solar has been the top source for new power for five years, Seia said. Seia and Wood Mackenzie said solar and battery storage were practically the only energy resources being built in the first quarter, making up 91% of all new generating capacity.

The Trump administration has canceled solar and wind projects, implemented policies that slowed clean energy permitting and development and terminated $7bn in funding intended for affordable solar energy projects across the US.