Great River Energy has reached an agreement to build one of the largest wind farms in North Dakota.

The deal announced Tuesday with developer Apex Clean Energy comes nearly two weeks after Minnesota utility regulators approved the controversial sale of Great River's 436-mile power line from North Dakota to the Twin Cities.

Maple Grove-based Great River sold the power line along with its big coal-fired power plant in McLean County N.D. Clean energy groups protested the sale because it will perpetuate the importation of coal-fired power into Minnesota.

Earlier this month, Great River disclosed it planned to build a major wind farm near the power plant, a move that could alleviate concerns that the power line would be dedicated to coal.

"This transaction opens a new pathway for Minnesota to receive renewable energy grants ensuring continued reliability and energy sufficiency," said Priti Patel, Great River's chief transmission officer, in a news release.

Great River is a wholesale power cooperative that sells electricity to 28 retail cooperatives that in turn serve around 700,000 Minnesotans.

The 400-megawatt wind farm announced Tuesday is expected to start operating in 2025; Great River will not own it, instead purchasing power under a 20-year agreement. Its price was not disclosed.

With the new North Dakota wind farm and other wind projects planned mostly for Minnesota, renewable power would rise from 25% to 57% of Great River's electricity generation between now and 2027.

Great River announced in May 2020 it would close Coal Creek — North Dakota largest coal-fired power plant — as it pivots to more wind and natural gas generation. Great River said the 1,100-megawatt Coal Creek plant had become such a money loser that it couldn't be sold for even $1.

But the state of North Dakota rallied to save Coal Creek, part of its economically important coal mining and power production industry. Great River sold the coal plant and power line to Bismarck-based Rainbow Energy Marketing for about $225 million — the power line's book value.

For three years under Rainbow, all of the coal plant's 1,050 megawatts of electricity production will flow on the power line to Great River. That number will then fall to 350 megawatts as renewable energy is added, including the new wind farm in McLean County.

Great River's original plan was not only to close Coal Creek, but to build a $1.5 billion wind farm that would have connected into the power line at the coal plant. But that plan was ditched after McLean County placed restrictions on new wind farm developments, a move aimed at keeping hopes alive for the coal plant.

Now that Coal Creek has been saved, the county has indicated it will drop its restrictions on wind farms.