PSE has developed and maintained the electric system on Bainbridge Island for several decades. As the Bainbridge population increased, so did the demand for power. We expand our electric system to meet the demand and support energy efficiency investments on the Island. The Island's population has increased from 637 residents in 1950, to over 23,800 residents in 2015. 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:
- Electricity is generated at a place such as Wild Horse Wind & Solar Facility or Baker Dam.
- Two high-voltage (115 kV) transmission lines carry energy across Agate Pass to reach the island's three substations.
- Medium-voltage power is distributed from each substation through a series of distribution lines to more than 12,000 customers where they live, work and play.
Being an island is one of the biggest challenges to reliability because there is no surrounding electric system to support the island's electric system infrastructure. 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 56% of the island's distribution lines underground (see map). While effective, undergrounding distribution lines is three to four times more expensive than overhead construction. An outage underground also takes several days or weeks to repair, compared to several hours for many non-storm overhead outages.
- 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.
What we do when the power goes out
There's a science to restoring customers' power as quickly and efficiently as possible. We start as close to the source of generation as we can and work our way down the transmission lines to the smaller distribution circuits that feed communities and neighborhoods. Why? Because until we've found and repaired the damage to the large transmission lines, we will not know the extent of the damage further down the line. This method also ensures the most customers have their power restored as quickly as possible. We also prioritize essential services, such as hospitals, water systems, energy and transportation.
When PSE customers lose power, there is no higher priority for us than getting it safely restored. In a large storm, hundreds of PSE employees and our service provider partners work tirelessly from a large network of local storm bases and our emergency operations center to get the lights back on. Learn more about our storm response here.