Seattle City Light Testing Self-Healing Power Lines

Crews install an automated switch in Shoreline.

Seattle City Light will test automated switching technology in Shoreline and Lake Forest Park that is designed to speed the restoration of service when a power line is damaged.

The equipment is being installed on two feeder lines and is expected to be operational before storm season begins in the fall.

It detects outages, isolates the section of a circuit that is affected and then re-routes power to restore service to the areas that are not directly affected. All of this takes place in a matter of seconds.

“Customers will no longer have to wait for a crew to arrive for the first steps of power restoration to begin,” Energy Delivery Operations Director Bernie Ziemianek said. “And the crews will know where to go to make repairs, further speeding the restoration of service.”

City Light will test the equipment through storm season. If the equipment proves successful, the utility intends to install it on other feeder lines across its service territory.

Lineworkers prepare to install an automated switch in Shoreline.

The equipment, called distribution automation, is part of a larger effort to build a smarter grid in Seattle. Other components include technology to monitor and control substations, advanced meters and components to optimize the delivery of electricity to customers. As City Light installs this technology, the utility will be able to reduce energy losses, improve the integration of electricity generated by solar panels on customers’ roofs and provide enhanced support for customers with electric vehicles.

“We are using technology to make our distribution system more reliable, our operations more efficient and to make sure that City Light remains the nation’s greenest utility,” said Michael Pesin, who is the architect of the Seattle Smart Grid.

Seattle City Light is the 10th largest public electric utility in the United States. It has some of the lowest cost customer rates of any urban utility, providing reliable, renewable and environmentally responsible power to about 750,000 Seattle area residents. City Light has been greenhouse gas neutral since 2005, the first electric utility in the nation to achieve that distinction.