Under the executive order, federal agencies must review all regulations and policies that obstruct or impose significant costs on energy resources. The order revoked energy- and climate-related presidential and regulatory actions put in place during the Obama administration, including a requirement to consider greenhouse-gas emissions and the effects of climate change in National Environmental Policy Act reviews.

It also lays the groundwork for rescinding the Clean Power Plan (CPP), President Obama’s effort to combat climate change by reducing carbon emissions from power plants, and disbands the working group on the social cost of greenhouse gases. Interior Secretary Ryan Zinke immediately overturned the 2016 moratorium on new coal leases on federal lands, as required by the order.

“Change in the energy market has more to do with economics than environmental policies,” says Paul Patterson, an analyst with Glenrock Associates. “Fracking changed everything. It was a frontal assault on coal and nuclear.”

Low natural-gas prices caused by the abundance of gas from hydraulic fracturing has displaced coal.

In 2010, the PJM Interconnection, which operates the largest wholesale energy market in the U.S., had 49.3% of its electricity produced by coal and 11.7% produced by natural gas. “In 2016, coal produced 33.9%, and gas produced 26.7%,” says Ray Dotter, a spokesman.

Now technology improvements are pushing solar and wind prices low enough to compete. Julien Dumoulin-Smith, a UBS analyst, says removing the CPP could accelerate the demand for solar resources. He also believes cost trends will move the Southeast toward solar construction for incremental energy needs.

Elsewhere, Xcel Energy notes that, in the Southwest, wind generation is cheaper than coal and natural-gas power. In March, the company said it would build 1,550 MW of wind in the upper Midwest and 1,230 MW in Texas and New Mexico. “Wind energy is at historically low prices right now, so we’re able to reduce emissions while securing long-term cost savings for our customers,” says Chris Clark, president, Xcel Energy, Minnesota.

Trump said his executive order would bring back coal miners’ jobs, but just two days later, Texas-based Vistra Energy said three of its coal-fired plants are at risk of closing.

And PNM Resources on March 16 said a preliminary analysis shows closing two remaining units at the 1,848-MW San Juan plant in New Mexico could provide long-term benefits and allow increased renewable production.

More than 190 coal-fired plants closed between 2005 and 2015. NRG Energy opted to convert three coal-fired plants and an additional unit to burn natural gas, and it could convert another. “It made economic and environmental sense,” says NRG spokesman David Gaier. NRG has made companywide goals to decarbonize power generation. Competitive, market-based solutions drive the most environmental protection at the lowest costs, he says.

While states and industry likely will see a more supportive environment as a result of the executive order, “it remains to be seen what kind of effect these actions will ultimately have on a power sector that has moved away from coal in favor of cheaper natural gas and growing renewables,” says James Rubin, former assistant chief in the Justice Dept.’s law and policy section.