Installation of third 150-ton transformer marks the completion of crucial reliability project.
Over the last few years, crews have been hard at work installing new transformers at our East Pine Substation. And this weekend, they will switch on the newest and final transformer. This marks the conclusion of a multi-year effort to improve reliability for customers served by the substation.
Substations are part of our electrical generation, transmission, and distribution system. They transform voltage from high to low, or low to high, and perform several other important functions. East Pine is what’s known as a “distribution substation.” This type of substation ensures the electricity that flows through the communities we serve is safe and reliable.
Not only will transformer upgrades improve power reliability, they also build load capacity and allow for greater control and monitoring capabilities.
Transformer upgrades
The East Pine Substation houses four transformers powering Seattle’s Central District, First Hill, and Capitol Hill, including area hospitals. Aside from generators at our hydro facilities, these transformers are the largest and most expensive pieces of equipment in our electrical system.
Each transformer weighs over 100 tons – that’s more than two fully loaded semi-trucks or nearly four humpback whales. They convert high-voltage electricity carried from power generation sites to substations and lower the electric voltage level, ensuring safe power transmission to customers’ homes or businesses.
“Making matters a little more complex, the new transformers and other substation upgrades are physically larger than the previous equipment. Before we figured out how to physically move the equipment in, we needed to plan how the equipment would fit it in the space,” explained Hans Gutmann, Electrical Power Systems Principal Engineer.
Among all the East Pine upgrades, the transformers were the largest and most complex. Each one traveled hundreds of miles first by rail and then on heavy-load trucks on Interstate 5, before finally making its way carefully through the streets of Seattle. The new transformers have an expected lifespan of 40 to 50 years.
Why we upgraded
Since the 1960s, the East Pine Substation has been an essential part of how we deliver reliable, affordable, and environmentally responsible power to the communities we serve. In fact, it was even designated a Seattle Landmark in 2019 due to its award-winning architecture.
Upgrades were designed to improve power capacity as the community grows, enhance safety, and meet seismic standards. This was a massive undertaking made possible by many people throughout our utility including civil construction crews and engineers, structural and electrical engineers, our carpentry and paint shops, and substation crews and apprentices.
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.