Dry Creek Energy Storage Project

Overview 

To help maintain grid reliability and resiliency, we’re proposing to construct and operate a 160-megawatt (MW) and 640 megawatt-hour (MWh) Battery Energy Storage System (BESS). The project would connect to the Rancho Seco Solar II Substation Project.

We get our power from various sources including renewable energy such as solar. Our goal is a balanced and sustainable mix of sources. The proposed project stores energy from the electrical grid when customers’ demand for electricity is  low or we have excess generation, and returns it to the grid to provide electricity to customers during periods of higher demand, to provide our community with clean, renewable energy that aligns with our 2030 Zero Carbon Plan. 

Location 

We’re proposing the BESS site (site) as an alternate location within the fenced boundary at the decommissioned nuclear power plant due to constraints at the initially proposed location in the Rancho Seco Soar II Final Environmental Impact Report (FEIR). 

The site encompasses approximately 15 acres within the 87 fenced acres of the decommissioned Rancho Seco nuclear power plant in Herald, California. Rancho Seco Solar II (to the north), Rancho Seco Solar I (to the east) and the decommissioned nuclear power plant (to the south) surround the proposed site. 

Activities 

All portions of the site were previously modified during construction, operations and maintenance of the decommissioned nuclear power plant and adjacent cooling pond infrastructure. The current site includes paved areas and open, restored perennial vegetation.

Key activities during project construction include construction/installation of: 

  • Approximately 100 BESS containers in the identified acreage to accommodate setbacks, stormwater controls and/or O&M infrastructure, if needed. 
  • An onsite maintenance area, including a potential bathroom facility and stormwater infrastructure. 
  • Approximately half mile of underground and aboveground collection and communication lines connecting the BESS units to the existing collector solar substation. An overhead portion of the collection line will extend south from the southeastern side of the site and an underground line will extend southwest to the substation. 
  • Security fencing with warning signs around all BESS components in accordance with the National Electrical Safety Code and our standards. 
  • Gates at the entrance with graveled road to allow operations personnel to drive between the BESS units.
  • Access to the facility from the existing decommissioned nuclear power station parking lot and existing roads for Rancho Seco Solar II. 

Timeline

Construction would start in June 2026 and take approximately 12-18 months to complete.

Environmental considerations 

A California Environmental Quality Act (CEQA) addendum to the Rancho Seco Solar II Project (SCH Number 2017092042042) is being prepared to address the alternate location of the BESS.

Questions? 

Please email DryCreekEnergyStorage@smud.org.