Denny Substation - Not your typical substation
Simply put, the Denny Substation is one of a kind. It is unusual both in its design and in
its location in a dense urban neighborhood. The final design represents two years of work
by City Light and its design team, and reflects the input of area stakeholders and the
guidance of the Seattle Design Commission. It meets the functional need of supporting
and serving the expansion and growth of the area and the aspirational goal of being a
community asset. View the Denny Substation gallery
to see more images of the
Though the majority of the site will be utilized for substation operations, the design
reflects community priorities such as open space and sustainability
. The design includes over 44,000 square feet of open space,
on-site solar power, a heat recovery system to provide 100% of the required heating for many
facilities within the substation, and manyother sustainability features. The sustainability
elements reinforce City Light's commitment to environmental stewardship and energy conservation.
This unique design includes public benefits that will encourage a safe and active pedestrian
environment. The substation design features sloped enclosure walls that decrease the size
of the facility at the pedestrian level, creating a friendlier urban environment along
the edges. The sloped walls include metal cladding and translucent glass panels that will
emit a soft glow at night.
Additionally, as part of the terracing, an "elevated interpretative pedestrian walkway"
wraps the Denny Way edge and continues north along the alley. This elevated zone will
be fully accessible with gentle slopes to allow for views into the substation as well
as Denny Way and the cityscape. The substation is open in its design (without a roof),
although most of the substation equipment will be hidden from public view within buildings.
Other public benefits include places for gathering, an off-leash area,
public open space along Minor Avenue N and John Street, an event zone, alley improvements, and a
community space for events, meetings and lectures.
Inside the Substation
The following equipment will be housed
inside the Denny Substation
. The majority of the substation equipment will be housed in
enclosed structures only accessible by City Light personnel and technicians.
- (4-bays) 115kV Gas Insulated Switchgear (GIS)
- (3) 115-13.8kV power transformers
- (1) 115kV line reactor with integrated GIS
- (1) 13.8kV switchgear building
- (2) 13.8kV capacitor banks
- (3) 13.8kV grounding banks
- (1 lot) 115kV XLPE cable between equipment supplier equipment
- (1 lot) 15kV EPR cable between equipment supplier equipment