Energy Storage

Proposal calls for 2,000-MW pumped storage facility in Arizona

A proposal filed at the Federal Energy Regulatory Commission by a subsidiary of transmission company ITC Holdings Corporation calls for the construction of a 2,000-megawatt, closed-loop, pumped storage hydroelectric facility in Arizona. The project is intended to boost reliability and facilitate the integration of renewable energy in the southwestern part of the U.S.

The application was filed in late September by Big Chino Valley Pumped Storage LLC (Docket No. P-14859-000).

In the application, Big Chino Valley Pumped Storage states that renewable energy development in the southwestern U.S. will continue to grow during the next decade.

“Significant public policy goals have been established in Arizona and California, as well as surrounding states, to reduce greenhouse gas emissions and fuel cost uncertainty associated with thermal generation,” the application goes on to say.

“Thousands of megawatts of renewable generation capacity are planned to be added to the grid by 2030. Large-scale energy storage is essential for successful integration of variable energy resources while maintaining reliable grid operations,” Big Chino Valley Pumped Storage said.

The project’s location in north-central Arizona “is well-situated to firm variable energy generation in Arizona and the southwestern region of the United States and to support the successful implementation of public policy goals,” the application said.

Pumped storage hydroelectric generation is recognized as commercially feasible “bulk storage” technology, Big Chino Valley Pumped Storage said.

The project will use off-peak or excess energy to pump water from a lower reservoir to an upper reservoir during periods of low electrical demand or high intermittent generation supply. The project will provide “an economical supply of peaking capacity, as well as load following, system regulation through spinning reserve, and immediately available standby generating capacity, among other ancillary services,” the application states.

Big Chino Valley Pumped Storage also said that the closed-loop pumped storage project design maximizes the benefits to the electric system detailed in the application “while limiting consumptive water use to initial fill and reservoir surface water evaporation. During license application development, the applicant will research alternatives for avoiding and mitigating the project’s impact on regional water resources.”

Transmission element of proposal

Big Chino Valley Pumped Storage said that double-circuit transmission lines rated at 500-kV will transmit power from the project to the interstate grid, as follows: 

  • A 500-kV, 30-mile, line traversing northerly to interconnect with the existing Arizona Public Service owned- and operated Eldorado-Moenkopi 500-kV line or a planned and sited new Dine Navajo Transmission Project 500-kV line from Moenkopi, Ariz., to Marketplace;
  • A 500 kV, 54-mile, line traversing westerly to interconnect with an existing Western Area Power Administration owned and operated 230-kV line from Prescott, Ariz., to Peacock, to be upgraded to 500 kV; and
  • A 500 kV, 47-mile, line traversing easterly to interconnect with two Navajo Southern Transmission 500-kV lines owned by participants of the Navajo Generating Plant and operated by Arizona Public Service.

“Based on a preliminary analysis, applicant believes that at least two, and possibly all three, transmission lines may be necessary to market the full capacity of the project,” Big Chino Valley Pumped Storage said.

During the term of the preliminary permit, Big Chino Valley Pumped Storage will undertake additional engineering analyses and feasibility studies that will further inform the project’s transmission requirements, the application noted.

Additional information about ITC Holdings is available here.

Public power and pumped storage

Public power entities are already utilizing pumped storage. For example, the New York Power Authority operates the Blenheim-Gilboa Pumped Storage Power Plant.

The Tennessee Valley Authority's Raccoon Mountain Pumped-Storage Plant is TVA's largest hydroelectric facility.

Meanwhile, Missouri River Energy Services in late 2016 said that it had applied for a new permit to study the potential for a 1,200-megawatt pumped storage hydroelectric facility, known as the Gregory County Pumped Storage Project, on the Missouri River in south central South Dakota.