Four projects, one grid-scale mission.
Closed-loop pumped storage plants in Utah, California, and Nevada — each in the 2,000 MW class, each designed to store renewable energy and stabilize the western grid.
Intermountain Pumped Storage
- Capacity
- 1,200–2,000 MW
- Lower pool
- New DMAD 2 Reservoir
- Upper pool
- Canyon Mountains Range
- Interconnection
- 2 × 345 kV lines
About the project
The Intermountain Pumped Storage Project would be located 5 miles northeast of Delta and 7 miles west of Oak City, Utah, in Millard County. The project concept envisions the construction of a pumped storage power plant facility with capacity ranging from 1,200 MW to 2,000 MW, using a new DMAD 2 reservoir as the lower pool and a new reservoir in the Canyon Mountains Range as the upper pool. The project would operate in a closed loop.
The new DMAD 2 reservoir would store enough water for project operation and allow for additional water storage to be used for irrigation and water conveyance.
Upper reservoir alternatives
- Alternative 1: A new Dry Fork Reservoir at 6,200 ft elevation
- Alternative 2: A new Mill Canyon Reservoir at 6,600 ft elevation
- Alternative 3: A new Williams Reservoir at 7,140 ft elevation
Transmission paths
The plant would interconnect to the existing Intermountain AC Switchyard using two new 345 kV transmission lines, with three available paths to the regional network:
- Path 1 (California Path 27): power to Adelanto, CA through the existing 500 kV DC transmission line
- Path 2 (Utah Path 28): power to Mona through the existing 345 kV transmission lines to the east
- Path 3 (Nevada Path 29): power to Ely, NV through the existing Gonder IPP 230 kV transmission line
The project is expected to be most attractive to the Intermountain Power Agency, due to the proposed use of their existing resources in the area. Other electrical utilities in California and Nevada are expected to be interested in the project as a resource for storing and maximizing renewable energy use.
Haiwee Pumped Storage
- Capacity
- 1,600–2,000 MW
- Lower pool
- New North Haiwee Res. 2
- Interconnection
- 500 kV · LADWP / SCE
- Water source
- Existing LA Aqueduct
About the project
The proposed Haiwee Pumped Storage Project would be located 10 miles south of Olancha, California, in Inyo County. The project envisions a pumped storage power facility with capacity ranging from 1,600 MW to 2,000 MW, with a new North Haiwee Reservoir 2 located upstream of the existing North Haiwee Reservoir serving as the lower pool.
Upper reservoir alternatives
- Alternative 1: A new McCloud Reservoir at 5,260 ft elevation
- Alternative 2: A new Little Cactus Reservoir at 4,980 ft elevation
- Alternative 3: A new Haiwee Canyon Reservoir at 6,160 ft elevation
Seismic reliability benefit
The proposed North Haiwee Reservoir 2 would improve the seismic reliability of the existing North Haiwee Reservoir. Seismic studies have found the existing reservoir could potentially fail during a maximum credible earthquake, settling the dam crest and releasing a large volume of water. The new dam would act as a backup dam to ensure the safety of nearby populations and improve reliability of the existing reservoir for water conveyance.
Construction activities
- Earthworks and grading to obtain the proposed reservoir floor
- Realignment of sections of the existing Cactus Flats Road and North Haiwee Road
- Realignment of the existing LA Aqueduct reaching the existing North Haiwee Reservoir
- Construction of a diversion structure and connecting channel or pipeline to the proposed reservoir
Operation
The plant would operate as a closed-loop pumped storage facility. Its operation would not alter existing streams or the operation of the existing Haiwee Reservoirs. Reservoir filling would use water conveyed through the existing LA Aqueduct, and the connecting pipeline could regulate the aqueduct's water temperature — helping prevent ruptures in the aqueduct pipelines caused by temperature variations.
With the site land owned and operated by the Los Angeles Department of Water and Power (LADWP), the project would be most attractive to LADWP, and development would proceed under LADWP's supervision. Generated power would be transmitted through 500 kV lines interconnecting with the LADWP or Southern California Edison (SCE) transmission systems.
Pyramid Lake Pumped Storage
- Capacity
- 2,000 MW
- Hydraulic head
- Up to 2,900 ft
- Lower pool
- Existing Pyramid Lake
- Interconnection
- 500 kV · PDCI
About the project
The proposed Pyramid Lake Pumped Storage Project would be located 40 miles northeast of Reno, Nevada, in Washoe County. Pyramid Lake is bounded by the Lake Range on the east and the Virginia Mountains on the west, and is the discharge point of the Truckee River — the sole outlet of Lake Tahoe.
The project envisions a 2,000 MW plant using the existing Pyramid Lake as the lower pool and a new reservoir in the Lake Range as the upper pool. A hydraulic head of up to 2,900 ft would exist between the upper reservoir and Pyramid Lake.
Upper reservoir alternatives
- Alternative 1: A new San Emidio Reservoir at 6,700 ft elevation
- Alternative 2: A new Tohakum Peak Reservoir at 5,960 ft elevation
- Alternative 3: A new Lake Range Reservoir at 6,180 ft elevation
Interconnection and solar integration
The interconnection voltage would be 500 kV, connecting to the existing Pacific DC Intertie (PDCI) through a new Pyramid converter station, with power transmitted to the Sylmar Converter Station in the Los Angeles area.
To maximize pumped storage operation, the project proposes a new 2,000 MW solar PV farm on 14,000 acres along the northern or southern shore of Pyramid Lake. Solar energy produced during low-demand hours would be stored, allowing the project to deliver 2,000 MW of carbon-free electricity when demand is high. The project could also tentatively interconnect to the existing Windhub Substation for storing wind energy.
Benefits
- Provide 2,000 MW of clean energy to California's electrical grid
- Help meet California's goal to reach 100% renewable energy by 2045
- Reduce CO2 emissions and the use of fossil fuel energy sources
- Load balancing for intermittent renewable energy sources
- Environmentally friendly alternative to BESS
Walker Lake Pumped Storage
- Capacity
- 2,000 MW
- Lower pool
- Existing Walker Lake
- Upper pool
- Wassuk Range
- Interconnection
- 500 kV · PDCI
About the project
The proposed Walker Lake Pumped Storage Project would be located around 15 miles northwest of Hawthorne and 15 miles south of Schurz, in Mineral County, Nevada. The project envisions a 2,000 MW pumped storage plant using the existing Walker Lake as the lower pool and a new reservoir in the Wassuk Range as the upper pool, operating in a closed loop.
Upper reservoir alternatives
- Alternative 1: A new Bald Mountain Reservoir at 6,500 ft elevation
- Alternative 2: A new Copper Canyon Reservoir at 5,740 ft elevation
- Alternative 3: A new Dry Creek Reservoir at 6,560 ft elevation
Interconnection
The interconnection voltage would be 500 kV. The project would interconnect with the existing Pacific DC Intertie (PDCI) using a new 500 kV transmission corridor and a new Walker converter station, with power transmitted south to the Sylmar Converter Station in the Los Angeles area. Other electrical utilities in California and Nevada are expected to be interested in the project as a resource for storing and maximizing renewable energy use.