After years of recurring power outages on Treasure Island and Yerba Buena Island, city authorities are upgrading the power infrastructure to improve reliability and shorten repair times.
The San Francisco Public Utilities Commission (SFPUC) has installed two additional recloser devices in the power system that can help limit the duration of outages from bird strikes or fallen tree limbs. The electric switches automatically test electrical lines when there’s a disturbance, restoring electric power if the problem is temporary.
The agency is also installing 32 fault indicators, devices that can automatically pinpoint faults in the electric power system.
“Prior to the fault indicators being installed, we would have to patrol the island to find [the source of the outage],” said Barbara Hale, the assistant general manager at SFPUC in charge of power.
“The Treasure Island [and] Yerba Buena Island system that was built by the Navy many years ago doesn’t have some of the more modern technologies that makes for a more efficient identification of where an outage is occurring,” Hale added.
Repairing power outages on Treasure Island and Yerba Buena Island requires more time than a typical power outage as the electric infrastructure on the islands ranges from 40 to 50 years old, when the typical power system has a lifespan of only 25 to 30 years, according to officials.
The 3,000 residents of the islands have voiced their discontent about frequent electrical failures. In 2012, there were 22 outages on Treasure Island. While the number of power failures dipped between 2013 and 2018, there was another spike in 2019 when there were 17, up from five in 2018. Officials have recorded four outages so far this year.
According to SFPUC spokesperson Will Reisman, the reclosers and fault indicators that are being installed could have shortened the duration of nine of the 21 outages in 2019 and 2020. In particular, he noted that the reclosers would have reduced outages to less than a minute in six of those cases.
While new reclosers and fault indicators will help reduce the duration of power outages, SFPUC and developer Treasure Island Community are working on longer-term improvements like installing a new switchgear, which will increase the number of electrical circuits and prevent outages occurring across the whole island.
“The switchgear will automatically route power around lines that have faulted,” Hale said. “That will minimize the scope of outages when they do occur and allow us to make sure that the fewest customers are affected.”
Officials say that the switchgear is crucial as a redevelopment project in Treasure Island of 8,000 homes is underway. Supervisor Matt Haney, who represents Treasure Island, said in a statement: “Power outages have plagued Treasure Island residents for years, and with shelter-in-place resulting in more people staying at home for longer periods, power reliability is more vital than ever.”