Project Introduction

The Kingfisher Energy Storage project is a proposed Battery Energy Storage System (BESS) that will safely deliver reserve power to the local electrical grid, helping to keep the lights on for households, businesses, and critical infrastructure in King County during peak periods.

The project is designed to store power from the electrical grid (charge) when there is an excess of power being produced, and release power back to the electrical grid (discharge) when there is a shortage of power being produced. The facility will not generate any power, but only store and release power that was produced elsewhere, helping local communities avoid outages and service interruptions.

The region is increasingly at risk for grid disruptions, such as blackouts and brownouts, due to the impacts of extreme weather events in the summer and winter, increased demand for electricity resulting from the proliferation of electric vehicles, aging electrical infrastructure, and other factors.

Project development is being led by Tenaska, an independent energy company with proven expertise developing renewable generation assets and energy solutions that are enabling the clean energy transition, while meeting dynamic customer needs.

Project Status

The project is in the early stages of permitting and has begun sharing information with local stakeholders. The permitting process will include a comprehensive review of the project and multiple opportunities for public comment and engagement. Construction will begin once the permitting process is complete and electrical grid authorizations are in place.

Project Location

The proposed project site is located near the existing Berrydale Substation, allowing close access to the transmission system. This site will allow the facility to provide maximum support and value for the electric grid, while minimizing the overall project footprint. The facility will be operationally quiet, does not generate radiation or emissions, and will have no traffic impact when operating.

Project Overview

Grid Resiliency

The Kingfisher Energy Storage project will provide a new source of firm, dispatchable power for King County, strengthening existing electrical infrastructure and improving the resiliency and reliability of the local electrical grid. The Pacific Northwest region is increasingly at risk for blackouts, brownouts, and power supply inadequacy events due to population growth, extreme weather events, the proliferation of electric vehicles, and other factors.

Clean Energy Transition

The Kingfisher Energy Storage project will play a key role in supporting the community’s increasing use of intermittent renewable sources of power as Washington continues its clean energy transition. BESS projects are designed to store excess energy during periods of peak generation so it can be discharged to the grid during periods of peak demand.


Safety is the top priority in the design, construction and operation of battery energy storage systems. The Kingfisher Energy Storage project will be built with lithium iron phosphate (LFP) chemistry and other technological advancements that offer the highest standards in utility-scale BESS safety and reliability. Local first responders help oversee the process for ensuring appropriate safety plan and procedures, training, and equipment.

Low Impact Development

BESS facilities are operationally quiet and do not generate any air emissions or harmful radiation. The Kingfisher project requires a small physical footprint with little increase in traffic during construction and no increase once the facility is operational. The project will be built with a low elevation profile and will incorporate appropriate fencing and landscaping to match the aesthetics of the local community.

Jobs and Investment

The project will create jobs for the local workforce and economic development for King County. This includes local community expenditures, tax revenues, and sourcing of equipment, construction materials and labor. The project has committed to using union labor for construction, ensuring that jobs stay close to home and wages are spent locally.

Stakeholder Engagement

The project team is committed to engaging with local stakeholders throughout the process. Preliminary outreach to the community has begun and further project details and updates will be shared as the timeline moves forward. If you are interested in learning more about the project, please utilize our contact form below and a member of the team will get back to you within 72 hours.


Project Materials*

Frequently Asked Questions (updated 5.30.2023)

*Additional project materials will be added as the development process moves forward

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