Wisconsin regulators on Thursday approved Minnesota Power's $700 million natural gas plant for Superior.

In a 2-1 vote, the Public Service Commission of Wisconsin OK'd the Nemadji Trail Energy Center's certificate of public convenience and necessity.

The approval moves Duluth-based Minnesota Power's plan to build the plant with La Crosse-based Dairyland Power Cooperative forward on a plot of land between Enbridge Energy's Superior terminal and the Nemadji River. The power plant will be capable of producing between 525 and 625 megawatts of power.

"This is very significant for the (Nemadji Trail Energy Center) project in Superior," Julie Pierce, Minnesota Power's vice president of strategy and planning, told the News Tribune. "We received the approval from the Public Services Commission that this is the right site and it's in the public interest for having it in Superior, Wisconsin."

The companies argue the plant, which burns natural gas, would supplement more solar and wind power "when the sun isn't shining and the wind isn't blowing," and that the plant is "renewable enabling." Natural gas is a fossil fuel.

Minnesota Power has been reducing its reliance on fossil fuels, namely coal power, since 2005, when just 5% of its power came from renewables. Since then, it's retired seven of its nine coal units and invested more in wind and solar.

Minnesota Power expects 50% of its power will be generated by renewable resources in 2021, up from 30% today.

Environmental groups have argued the company should not replace coal with another fossil fuel, and that the plant was unneccessary and would contribute to climate change.

In a news release, Sierra Club Campaign Representative Matt Earley said the group was "disappointed" in Thursday's decision.

"Utilities need to get it out of their head that gas is a cheaper and cleaner alternative to coal. It’s simply not true. From the point it is fracked out of the ground, piped across the country, and finally burned at power plants, gas has dire impacts on our air, water, and climate that is just as bad as other fossil fuels like coal," Earley said.

The project still needs to obtain permits from the city of Superior, Wisconsin Department of Natural Resources and U.S. Army Corps of engineers.

Across the state border, the project faces further scrutiny from Minnesota regulators. Last month, the Minnesota Court of Appeals said the state's Public Utilities Commission erred when it declined to consider potential impacts the Nemadji Trail Energy Center could have on air, water, land and other natural resources. The court reversed the agency's October 2018 approval of the project and sent it back to the commission for further review.

Although the project is located in Wisconsin, it also had to move through Minnesota regulators because the power it would generate will be delivered to Minnesota Power's customers in Minnesota.

Minnesota Power said it will ask the Minnesota Supreme Court to review that decision because "the unprecedented and far-reaching nature of the ruling that could require the application of Minnesota environmental law in other states and have implications for all Minnesota companies building or contracting with facilities in other states," the company said in a news release Thursday.

In a statement to the News Tribune, Aaron Klemz, a spokesperson for the Minnesota Center for Environmental Advocacy, stressed the project still needs that environmental review from Minnesota regulators.

"Regardless of the Wisconsin PSC's decision, the Minnesota Court of Appeals decision means that Minnesota Power cannot build their proposed gas power plant," Klemz said. "The Court correctly decided that Minnesota law requires review of the proposal's effects on the climate and on the environment first."

Asked if construction on the plant could begin once all Wisconsin permits are in hand but the Minnesota environmental review was still incomplete, Pierce said "That's what the Minnesota Supreme Court will help us determine."

This story was updated at 5:53 p.m. with reaction from Minnesota Power and environmental groups. It was originally posted at 4:02 p.m.