HGE Energy Storage 1 LLC applied Aug. 5 at the Federal Energy Regulatory Commission for a preliminary permit on a 1,270-MW pumped storage hydro project located along the California coast and using seawater to make electricity.
The proposed project is in Sonoma County, Calif., near Jenner and Fort Ross. A preliminary permit, if approved by FERC, grants a party a 36-month, exclusive right to look at project development. A license application would need to be filed with the commission if the decision is to proceed from there. HGE Energy Storage 1 LLC is a wholly owned subsidiary of Hydro Green Energy LLC of Westmont, Ill.
“The pumped storage hydropower project will consist of a single new reservoir, created by the construction of embankments, joined with the Pacific Ocean by approximately 19,000 feet of conduit,” said the application. “Maximum hydraulic head will be 1,700 feet. Equipment will consist of five 254 MW, reversible variable-speed pump-turbines in a new powerhouse, totaling 1,270 MW of generating capacity. Annual energy production is projected to be approximately 3,714,406 MWh.”
The project will interconnect to the power grid via a new single-circuit 230-kV line of about 24.7 miles in length. The powerhouse and substation will be located near the Pacific Ocean, approximately 100 feet below ground level. Tentative dimensions are 250 feet long by 75 feet wide by 100 feet high.
A breakwater is planned for purposes of reducing water level fluctuation during pumping mode and to dissipate energy from discharge water during generation mode, helping to protect the marine environment in the Pacific Ocean.
Equipment will be designed for corrosion-resistance from this seawater, with extremely stringent leakage protection, marine organism fouling protection and other measures also required due to the use of seawater. The company said it has secured a letter of interest from a major equipment supplier for the project. This supplier provided equipment and has maintained a seawater pumped storage project in Japan since the early 1990s with no negative marine ecosystem consequences.
“The Project will be operated to provide support to variable, intermittent renewable resources being interconnected to the transmission grid in the State of California,” the application noted. “The Project will use the dynamic capabilities of pumped storage to provide ancillary services in the efficient integration of wind and solar resources from both an operational and economic standpoint.”