Seattle City Light , Net Zero Denny Substation
Winner of ACEC WA Best in State Silver Award
Project Interview Seattle ’ s first new substation in 30 years inspires its community to think differently about utility infrastructure and sets a new standard in urban utility design . The 110,000 SF Denny Substation powers a 13kV network covering Seattle ’ s densely-populated South Lake Union : an urban neighborhood that is a growing bioscience and technology office hub and home to many multi-family and senior housing developments and commercial and retail spaces .
The goal was to ensure reliable power and provide system flexibility for the area ’ s current and future electrical needs . But it ’ s more than an average electrical substation . Seattle City Light and the design team took the opportunity to create a new municipal development with a pop-up community space , an off-leash dog park , public artwork , learning center , and more that highlight Seattle City Light ’ s commitment to environmental stewardship and energy conservation .
Notkin a P2S Company , worked closely with the design team to define the projected energy use of two shelled spaces marked for community use and developed a strategy for the spaces to be “ Carbon Neutral ” by incorporating energy-efficient mechanical systems paired with solar photovoltaic arrays . These public spaces will generate up to 105 percent of their energy needs and achieve an energy use intensity ( EUI ) of 15.5 .
For some more info on the project , we spoke with Project Manager Robert Lauderdale .
What is your favorite design element of this project ? Robert Lauderdale : Combining old and new school technologies to achieve maximum energy savings . We utilized a campus-wide VRF system to harvest waste heat from the substation areas and used it in the public areas . We located the fan coils under a raised floor and supplied heating and cooling to the spaces via underfloor / displacement ventilation . A VAV ERV system provides ventilation , and when outside conditions are appropriate , the facility uses natural ventilation .
What were some particularly challenging aspects of the project ? How did you overcome them ? RL : The occupied spaces had exposed , sloping ceilings and a raised floor . The architectural vision was to house all of the mechanical distribution on the raised floor . I worked with the VRF and diffuser manufacturers to provide a system that would supply thermally acceptable air to occupants .
Why is this project valuable to the surrounding community ? RL : This project was essential to the growth of downtown Seattle . This substation feeds all of the new office building development in the South Lake Union area . Due to the size of the substation , a city street had to be vacated to gain enough real estate to accommodate the new substation . Since a street was vacated , Seattle City Light had to provide project elements targeted explicitly at the neighborhood . These elements included a dog park , community space , and an elevated walkway with artwork around the substation . The project also enhanced a bus stop that was located on the property .
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