GB Energy Park LLC (GBEP) applied Oct. 1 to the Federal Energy Regulatory Commission for an original license for the 400-MW Gordon Butte Closed Loop Pumped Storage Hydro Project in Montana.
The proposed action includes the construction and operation of a new off-stream, closed-loop pumped storage hydro facility located approximately three miles west of the unincorporated town of Martinsdale in Meagher County, Montana (population 207).
Pumped storage hydro involves using cheap electricity during certain slack demand times of the day to pump water uphill, then the release of that water to generate electricity during peak power demand periods. Such projects, which have been around for years, are considered particularly attractive right now as a way to even out the input of highly variable wind and solar capacity to the grid.
The project footprint will be 380 acres and the Area of Potential Effect (APE) of the proposed construction and operation of the project evaluated during preparation of this license application is approximately 2,026 acres. All project features will be located entirely on private land. The project will include the following features:
- An upper reservoir with an active storage of 4,070 acre feet
- An overflow spillway in the upper reservoir for emergency discharges
- An intake structure at the Upper Reservoir
- An 18 foot diameter shaft leading to a high pressure tunnel
- An 18 foot diameter concrete/steel lined tunnel from the shaft to the penstocks at powerhouse
- A series of steel penstocks leading to the powerhouse Units 1 through 4
- A powerhouse with four 100 MW Ternary units, each consisting of a motor-generator, a Pelton turbine and a multi-stage pump
- A lower reservoir with an active storage of 4,070 acre feet
- A hydraulic connection to the existing, non-project 71 Ranch irrigation system
- A substation with generator step-up transformers and switchgear at the powerhouse
- A 230-kV transmission line
- An interconnection substation tying the 230-kV transmission line to an existing 500-kV line
After leaving the powerhouse substation take-off structures, the 230-kV transmission line will run generally southwest for three miles and cross Cottonwood Creek. It will then turn generally south for another 2.7 miles, paralleling Cottonwood Creek Road, to a new interconnection substation at the existing Colstrip twin 500-kV transmission line (managed by Northwestern Energy). The new transmission line will run entirely on 71 Ranch property and generally cross level terrain.
At the interconnection substation, the 230-kV transmission line will be connected to a 230kV/500kV step-up transformer. From there the line will be connected through a series of buses, circuit breakers and disconnect switches to the 500-kV line going west to Garrison and the 500-kV line going east to Broadview.
Project contact information is: GB Energy Park LLC, 209 South Willson Ave., PO Box 309, Bozeman, MT 59771, (406) 585-3006.