The US should stop the closure of coal-fired power plants, Energy Secretary Chris Wright said, adding the fuel source would be essential to the nation’s power system for decades to come.

“We are on a path to continually shrink the electricity we generate from coal,” Wright said Tuesday on Bloomberg Television. “That has made electricity more expensive and our grid less stable.”

Wright’s remarks come as demand for electricity is surging to feed power-thirsty data centers needed for artificial intelligence, new factories and the overall electrification of the economy.

President Donald Trump has called for more steady sources of power while criticizing renewable energy as unreliable. While natural gas-fired plants are expected to supply the bulk of growth in the short term, Trump last month floated the dirtiest fossil fuel as a power source for data centers.

Still, Wright acknowledged that a renaissance for the fuel source is unlikely. Coal-fired power has struggled against cheap natural gas and to a lesser extend renewable energy — and has faced regulatory pushback as a dirty fossil fuel. Coal accounts for about 15% of power generation in the US today, down from more than half in 2000, according to the US Energy Information Administration

“The best we can hope for in the short-term is to stop the closure of coal power plants,” Wright said. “No one has won by that action.”

It’s not immediately clear what actions the US could take to help prevent coal-fired power plants from closing. Trump’s first term was marked by a series of efforts to throw a lifeline to cash-strapped coal plants. The administration in one case considered ordering some to stay online to “serve the public interest” and in another forcing the nation’s grid operators to buy their electricity.

Coal power advocates say they are hopeful a national energy emergency declared by Trump on his first day in office provides an avenue for the government to intervene. More than 120 coal-fired power plants are scheduled to be shut down nationwide over the next five years, said Michelle Bloodworth, president of the America’s Power trade group representing utilities and miners such as Peabody Energy and Core Natural Resources.

“Many of these coal plants are being shut down because bad policies have made them uneconomic,” Bloodworth said. “Fortunately, President Trump is seeking to change this.”

Environmentalists, on the other hand, have cheered coal’s demise, citing the global warming emissions associated with burning the fossil fuel.

“Coal has been uneconomic compared to every other energy source except for nuclear power for quite a few years now,” Erich Pica, president of Friends of the Earth, said in an interview. “The only way you keep coal plants operating is if the federal government subsidizes the heck out of this extinguishing energy source.”