Project overview

Puget Sound Energy is evaluating potential upgrades at the Foss Corner substation in Kitsap County. The Foss Corner substation upgrades would be needed to interconnect with BrightNight Power’s Agate Battery Energy Storage System (BESS) project which would be located adjacent to the substation. The Agate BESS is going through the permitting process and is not yet an approved project.

Soil sampling – Sept. 10 at night
As part of the technical analysis for the interconnection request, we need to understand the ground conditions near the Foss Corner substation. Crews plan to collect soil samples near the substation on Bond Rd. NE from Thurs., Sept. 10 at 8 p.m. to Fri., Sept. 11 at 6 a.m. Because this work requires a lane closure on Bond Rd., crews will work at night to reduce traffic impacts and improve safety.

Possible upgrades at the Foss Corner substation
If the interconnection is feasible, then PSE will upgrade the Foss Corner substation. We anticipate that this work will:

• Rebuild the substation inside the existing fence, including breakers, towers, switches, a control house and associated equipment
• Relocate and reorient the substation infrastructure and transmission lines to accommodate the new substation configuration
• Install metering to measure how much energy flows between the BESS project and our electric grid

Next steps
PSE is still in the design and permitting phase for the Foss Corner substation upgrades, which is required work to prepare for the interconnection. If the Agate BESS is approved, we will finalize the designs for the Foss Corner substation improvements. Construction on the Foss Corner substation could start as soon as late 2027 and last about one year. Then, the substation would be ready to interconnect to the Agate BESS project. This schedule could change, and we will keep you updated.

Questions? 
If you have questions about our work at the Foss Corner substation, please contact us at 1-888-404-8773 and MajorProjects@pse.com. If you have questions about the Agate BESS project, please visit BrightNight Power’s website to learn more and contact them.