Final design is due to be finished in 2017 with construction expected to start in 2018.
The project will use ternary equipment from GE Renewables, which will let the plant shift between generating and pumping.
Absaroka claims that this can help in creating the least experience and highly capable capacity to meet daily energy needs of the state’s residential and commercial customers.
The closed-loop project and will be located 3 miles west of Martinsdale and 6 miles from the Colstrip twin 500 kV transmission lines, the backbone of Montana’s electric system.
The close proximity of the interconnection gives the project an advantage of access to markets in the state and throughout the region.
It is a rechargeable utility-scale battery that can solve one of the most difficult challenges being faced by the nation’s electrical grid, which is power fluctuations.
Absaroka Energy president Carl Borgquist said: "This is a tremendous milestone achieved by a world-class team including Barnard, SNC-Lavalin and GE Renewables.
"I'm so proud of our team who have worked diligently together to accomplish this significant milestone on the journey to project completion."
Governor Bullock said: "Montanans are blessed to live in a place with a rich and diverse supply of energy resources that have provided us not only affordable power but also a way to make a living for thousands of hardworking families across the state.
"By advancing pumped storage projects like this to our energy mix, Montana is helping chart the path to an affordable energy future that strengthens our rural communities, provides job creation opportunities for even more energy development, all while safeguarding our quality of life."
Image: Gordon Butte Pumped Storage Hydro project, sited in central Montana, is a rechargeable utility-scaled sized battery that is unique in its capability to firm up variable energy generation. Photo: Courtesy of PRNewswire.
