Spion Kop Wind, a subsidiary of Compass Wind, will develop and construct the wind power project in Judith Basin County.
Earlier, NorthWestern signed a memorandum of understanding with Compass to buy a 24MW wind facility in central Montana, and has increased the size of the Spion Kop wind project to 40MW.
The purchase price is $1,947 per kW for each kW of the total nameplate capacity included in the project, which is equal to $77.88m.
The purchase is subject to pre-approval of the wind project by the Montana Public Service Commission to include the project in NorthWestern’s rate base.
The company said the wind facility will begin commercial operations by the end of next year.
Both the energy and associated renewable energy credits will be placed into the electric supply portfolio and used to meet future renewable portfolio standards obligations.