DETROIT (AP) -- The U.S. Energy Department ordered a Michigan coal-fired power plant to remain open, at least until late August, citing possible electricity shortfalls in the central U.S.

State regulators immediately fired back, saying it's unnecessary to keep Consumers Energy's J.H. Campbell plant open. It was supposed to close May 31.

"We currently produce more energy in Michigan than needed. As a result, there is no existing energy emergency in either Michigan or MISO," said Dan Scripps, chair of the Michigan Public Service Commission.

MISO stands for Midcontinent Independent System Operator, which manages the flow of electricity in 15 U.S. states and Manitoba in Canada.

MISO's forecast says there should be enough electricity in the region this summer though "there is the potential for elevated risk during extreme weather."

Consumers Energy is planning to close Campbell as part of a transition to cleaner energy. The power plant opened in 1962 in western Michigan's Ottawa County, near Lake Michigan. It can generate up to 1,450 megawatts of electricity to serve up to 1 million people, the utility said.

"MISO and Consumers Energy shall take all measures necessary to ensure that the Campbell Plant is available to operate," Energy Secretary Chris Wright said Friday.

The utility said it will comply with the order, which expires Aug. 21.

"Yes, the plant will stay on and produce electricity," spokesperson Brian Wheeler said Tuesday.

An environmental group, the Sierra Club, panned the government order.

"Coal is expensive, outdated and deadly. ... Consumers Energy is right to finally retire this hugely expensive plant that is costing Michiganders their lives," attorney Greg Wannier said, referring to the health effects of coal emissions.