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How Seattle City Light Is Securing a Reliable Future 

Tamara Jenkins is Seattle City Light’s Project Delivery Director.

Previously, we talked about the importance of reliable infrastructure. This includes everything from our power generation sites to the distribution lines that bring electricity directly to your homes and businesses. Today, I’m excited to share how Seattle City Light is investing in and modernizing these critical assets. We are working to ensure you receive reliable power now and in the future. Our crews have been busy making system improvements and completing preventive maintenance projects.

Here’s a look at several key projects helping us secure a reliable future.

Several projects lighting the way forward

A look at the new 125-ton power transformer arriving at the East Pine Substation.

East Pine Substation transformer replacement

In early July, a modern 125-ton power transformer arrived at the East Pine Substation in the Central District. This critical piece of infrastructure will replace an aging transformer at the substation. This substation powers the neighborhood and hospitals on First Hill and Capitol Hill.

The new transformer is the second of three replacements in a multi-year project. This work will help increase capacity, meet anticipated growth, and improve reliability.

Broad Street Substation Inductor Project

A reactor being delivered to the Broad Street Substation earlier this year.

We’re making system improvements to the Broad Street Substation near Seattle Center. These improvements consist of installing new electrical equipment called inductors. These large electrical wire coils store and help regulate the flow of electricity on the transmission line.

These improvements will reduce congestion and upgrade the reliability of the transmission system. This means fewer regionwide outages and a more stable power supply.

Underground cable replacement

Underground direct-buried cable does not last forever. After it has been in the ground for 30 to 40 years, it becomes susceptible to cracks in the insulation.

We broke ground in the Hurstwood neighborhood in Burien to install a new underground electrical system. The new cables will be placed in protective conduits, minimizing future failures and disruptions.

Metro electric bus base

We’re partnering with King County Metro to energize its first 100% electric bus base in Tukwila. The zero-emissions base will support 120 battery electric bus chargers, reducing emissions and supporting sustainable public transportation.

The base will also accommodate zero-emission vehicles that aren’t used for passenger service. We are aiming to provide power to the site by the end of the year, with the base scheduled to begin service in early 2026.

King County Metro’s new battery-electric bus being charged at the South Base campus.

Shore power projects

Shore power electrification is key to reducing seaport emissions. In 2023, we electrified cargo ship shore power at the Port of Seattle’s Terminal 5. In January, a mile-long cable was placed on the ocean floor along Elliot Bay.

The cable will connect power from Terminal 46 to Pier 66 and provide power to cruise ships later this year. Electrifying the Bell Street Cruise Terminal at Pier 66 allows cruise ships to turn off their diesel-powered engines while at berth and plug into the electrical grid.

Distribution line sensors

Crews install fault location, isolation, and service restoration (FLISR) equipment. FLISR helps provide support for detecting outages.

We’re replacing aging fault-current indicators with smart line sensors. The new system is known as FLISR – fault location, isolation, and service restoration. FLISR is one of several distribution automation technologies we’re implementing to make the grid more reliable and resilient.

When an outage happens, the sensors can locate and isolate faults. The technology can then reconfigure the flow of electricity. This reduces the number of customers affected and the time it takes to restore power. We installed this technology at five University Substation feeders last year. A project at the Creston Nelson Substation is underway.

T-Mobile Park cable replacement

During the Seattle Mariners’ Major League Baseball All-Star break, our crews worked through the night to reinstall and revitalize aging cables at T-Mobile Park. (T-Mobile Park celebrated its 25th anniversary on July 15!) We partnered with the Seattle Mariners to complete this project safely and efficiently, ensuring that game days remain uninterrupted.

The Importance of regular maintenance

In addition to major projects, routine maintenance is crucial for a reliable grid. Here are some other electrical system improvements and preventative maintenance.

Pole replacement

We replace aging utility poles throughout our service area to enhance safety and reliability. Our Pole Replacement Program monitors 92,000 poles in our service area. We inspect and test 10% of the wooden poles annually, ensuring that we revisit each every 10 years. Based on the findings, we either treat or replace the poles. In the last five years, we have replaced more than 6,000 aging and/or deteriorating wood poles. This year, we are on target to replace an additional 1,600 poles.

Streetlight replacement

We replace aging streetlights to improve reliability, safety, and lighting in neighborhoods. We maintain an inventory of more than 65,000 streetlights. In-progress and upcoming projects to include work in Magnolia, Queen Anne, and Lake City.

Vegetation management

Our Power Line Clearance team ensures the reliability of our electrical service and the safety of our communities. They trim trees and manage vegetation around our network of substations, power lines, and transformers. This work helps reduces the risk of power outages caused by fallen branches.

Investing in the future

These projects go beyond repairs. They’re investments in a stronger, more reliable grid for generations to come. By improving our infrastructure, we’re keeping your lights on today and paving the way for a brighter tomorrow.

We look forward to sharing more updates as we continue to improve our services and support our region’s growth. You can learn more about our current projects here.