Posted on by Willem

Sunday/ Denny substation update

I went down to check on the construction of Seattle’s sleek new $209 million substation in South Lake Union today. Its construction has been three years in the making – and its planning much longer than that. Seattle City Light purchased the site from the Greyhound bus company in October 2008.

The work inside the substation is basically done, and the equipment has been energized. The walkways on its perimeter and the little public park are not yet open, though. There is also ongoing work done for building out an underground distribution network, scheduled to be completed in 2020.

Here’s a diagram that shows the incoming transmission lines (green), as well as the power distribution lines (lime green and orange). As substations go, this one is a decent size in terms of capacity, but not as big as a national grid substation. For now its capacity is 50 MVA (Megavolt-Ampere), but this could be increased up to 405 MVA to meet future power demands. The gas-insulated switchgear allowed for a smaller footprint for the substation.
Here’s the ground view from John St, looking toward Denny Way. I believe there is still some artwork that will be installed in the little public park: a 110 ft tall transmission tower-morphed-into-a-tree!
‘Seattle City Light Denny Substation’ says the lettering. This is looking west along John St. Space Needle on the right edge of the picture. The two trucks are parked in front of garage doors that allow maintenance vehicles to go into the substation.
And this will be the entrance to the information kiosk on Denny Way.

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