Project Overview
| Detail | Value |
|---|---|
| Developer | Jupiter Power LLC (owned by BlackRock, Austin TX) |
| Prior developer | Accelergen Energy (“Snoqualmie Energy Storage”) |
| Landowner | Snoqualmie 55 LLC — Burnstead Construction / Pine Forest Properties |
| Type | Lithium-ion battery energy storage (BESS) |
| Capacity | 130 MW / ~520 MWh (4-hour duration) |
| Site | ~45 acres across 5 parcels, unincorporated King County |
| Zoning | UR (Urban Reserve) — BESS is a permitted use, no Conditional Use Permit (CUP) required |
| Interconnection | 115kV tie-line to PSE Mt. Si substation |
| PSE agreement | Tolling agreement executed August 22, 2025 |
| Operations target | Late 2028 |
| Fire district | King County Fire Protection District No. 38 |
| Projected tax revenue | $783,000–$1,130,000/year in years 3–12 |
| Contact | Gage Fuller, cascadiaridge@jupiterpower.io |
What the facility would include
- Lithium-ion battery modules housed in prefabricated enclosures (standard utility-scale BESS design)
- Thermal management / cooling systems (fans, HVAC — these run 24/7)
- Fire detection and suppression equipment
- Inverters, transformers, and substation
- Perimeter fencing and security gates
- 115kV generator tie-line to Mt. Si substation
Jupiter Power
Founded 2017, acquired by BlackRock (Diversified Infrastructure) in late 2022. About 8,000 MWh of battery storage operating or under construction, 11,000+ MW battery storage pipeline.
They’re also behind the Blackberry Grove project (100 MW) near Hillsboro, Oregon — the most contested land use case in Washington County history, opposed by the No Batteries In Backyards group.
In 2025, Jupiter Power signed a $500 million / 4.75 GWh supply agreement with Peak Energy for sodium-ion batteries — a chemistry with no thermal runaway, no toxic off-gassing, and passive cooling. CTO Mike Geier called it a “potential game changer.” The company proposing lithium-ion for Snoqualmie Ridge is spending half a billion dollars on the technology that would fix the problems Snoqualmie Ridge is worried about.
PSE tolling agreement
PSE ran a voluntary All-Source RFP in July 2024 (UTC Docket UE-240532) for CETA-compliant resources and got 98 proposals. The Cascadia Ridge tolling agreement was signed August 22, 2025 and filed with the UTC on September 19, 2025. The financial terms are entirely confidential.
PSE needs storage to hit its CETA targets: up to 2.3 million annual MWh from clean resources by 2030, and up to 1,755 MW of summer peak capacity by 2029. The alternatives are overbuilding generation (expensive, and ratepayers pay for it) or keeping fossil fuel peakers online (which violates CETA).
Community response
Residents spoke against the project at the March 9, 2026 Snoqualmie City Council meeting. Concerns included proximity to neighborhoods and parks, fire risk, noise, air and light pollution, and impacts on fish-bearing streams.
Councilmember Dan Murphy: “Industrial battery storage doesn’t belong in the middle of a neighborhood.”
Snoqualmie’s Comprehensive Plan designates this site for “master-planned business park” and “innovative mixed use.” Not industrial battery storage. The Comp Plan puts utility and power generation uses near the city’s sewer treatment plant off Millpond Road, near SR 202.