MDU has asked the North Dakota Public Service Commission for an “Advanced Determination of Prudence” for a new natural gas power generation facility.
The 88 megawatt unit would be built at the Heskett Station, north of Mandan.
MDU spokesman Mark Hanson said the utility is retiring three aging coal plants -- Heskett One and Two, as well as the Lewis and Clark Station in Sidney, Montana.
"Two of the three units are 60 years old or older, and one is just under 60," Hanson said. "They have been reliable for a long time. But they're at a point where they're not as efficient, and just don't run as often as they can in today's market."
The new natural gas unit will be a “peaking plant.”
"It can start up in short order, if it's called upon during a peak need," Hanson said.
Hanson said MDU’s plan is to combine the peaking plants with power purchases in the market.
"This plans will be about half the cost to our customers, than if we were to continue to operate those three older coal units," Hanson said.
The project will cost $73 million. Hanson said if the PSC approves, the project could be on-line by the first quarter of 2023.