Bainbridge Electric System

PSE has developed and maintained the electric system on Bainbridge Island since the early 20th century. As the Bainbridge population increased, so did the demand for power. We expand our electric system to meet demand and support energy efficiency investments on the Island. The Island’s population has increased from just over 4,000 residents in 1950, to nearly 25,000 residents as of 2022. As population continues to grow, investments in infrastructure, reliability and energy efficiency will be needed to provide safe, reliable, efficient power into the future.

How power gets to you

Bainbridge Island’s electricity goes through a series of steps before it reaches you:

  1. Electricity is generated at a place such as Wild Horse Wind & Solar Facility or Baker Dam. 
  2. Two high-voltage (115 kV) transmission lines carry energy across Agate Pass to reach the island’s three substations: Port Madison, Winslow and Murden Cove.
  3. Medium-voltage power is distributed from each substation through a series of distribution lines to more than 12,500 customers.
The graphic on the left shows how power gets to Bainbridge Island. The map displays the electric system including the three substations on Bainbridge Island.
Click graphic to view a PDF version

Did you know over half of Bainbridge’s distribution lines are located underground?

The geography of an island poses unique challenges for electric reliability, mainly the lack of neighboring infrastructure to serve as a back-up. There are two fundamental ways to increase reliability:

  • Eliminate the cause of the outage: The combination of high winds, winter storms and tall trees mean trees are the #1 cause of outages on the island. That’s why we perform tree trimming every year, install tree wire on overhead lines so they can better withstand falling tree limbs, and have put 57 percent of the island’s distribution lines underground. While effective, undergrounding distribution lines is three to four times more expensive than overhead construction and is only pursued when the project fulfills a strict set of criteria.
  • Develop and maintain redundancy in the electric system: PSE completes reliability projects every year, from rebuilding transmission and distribution lines to installing tree wire and underground distribution lines. We also support energy efficiency programs to reduce demand on the system. To further increase reliability, existing systems can be “looped” so if one part of the system goes out, another part of the system can pitch in to keep the lights on.

For more information on PSE’s reliability investments, please see Current ProjectsCompleted Projects or the Frequently Asked Questions about reliability.

Bainbridge island transmission lines and substations

A graphic illustrating why the power goes out at substations and what parts of the Island lose power.

Three substations serve approximately 12,970 island customers

Bainbridge Island existing transmission power grid map

When PSE customers lose power, there is no higher priority for us than getting it safely restored. Visit or read our FAQs to learn more.