Montana based Absaroka Energy, LLC is developing the Banner Mountain Pumped Storage Hydro Project (Project) through its single purpose subsidy, BM Energy Park, LLC.  Banner Mountain is located at the northern end of the Laramie Mountains, a range of moderately high peaks on the eastern edge of the Rocky Mountains in northern Colorado and southern Wyoming. Banner Mountain is located in Converse County along its western border with Natrona County, approximately 13.3 miles southeast of  Casper, WY (population 59,628) and approximately 14 miles southwest of Glenrock, WY (population 2,576). Banner Mountain is sits at an elevation of approximately 7,283 ft. with an estimated 1,200 ft. of relief.

View a comprehensive overview of the Banner Mountain Pumped Storage Hydro Project click here

The new closed loop pumped storage hydro facility will consist of two new reservoirs, one on top of Banner Mountain and one at the base, connected to one another by an underground concrete and steel-lined penstock (large tunnel). The topographic relief of the mountain will result in an elevation difference of approximately 1,175 feet from the upper to the lower reservoir. The reservoirs – which are more like large ponds – will be equally sized at 4,000 acre-feet (or approximately 70 acres of surface area) and lined to prevent seepage. The penstock will terminate at a powerhouse built adjacent to the lower reservoir that will house the pump/turbine units.

Project Data:

  • Estimated Average Annual Energy: 1,300 GWh
  • Installed Capacity – 400 MW
  • Number of Pump / Turbine Units: 3
  • Upper/Lower Reservoirs – Equally Sized at 4,000 ac/ft
  • Head (elevation difference between reservoirs): 1,175 Feet
  • Powerhouse – Open Pit, Located Adjacent to the Lower Reservoir
  • Water Source – Deer Creek

The basic concept of pumped storage hydro is simple – the facility will use cost–effective energy from the grid to pump water to the upper reservoir, storing energy. When energy is needed, water will flow down the penstock and through the turbines. The Project will move water back and forth (closed loop) between the two reservoirs 24 hours a day, 7 days a week in response to the daily needs of the grid.

The Banner Mountain Project will be a utility-scale energy storage, regulation, and generation facility that will work as a highly flexible, fast-acting platform offering balancing services to the regional transmission grid. Once operational, this facility will provide regulation and other critical ancillary services to the grid – increasing the reliability and integration of new sources of renewable energy generation, preserving our existing transmission infrastructure, helping to grow our renewable energy portfolio, and bring jobs and economic opportunity to rural Wyoming.

BM Energy Park, LLC has received a preliminary permit from the Federal Energy Regulatory Commission (FERC) to begin a multi-year licensing process. BM Energy Park is currently in consultations with state and federal agencies, local landowners, environmental groups, and other interested stakeholders to identify, study and mitigate important issues related to the construction of this project.