Power restored at SLAC after outage
Power was restored Friday, May 20, at the Stanford Linear Accelerator Center (SLAC) after an outage caused by a falling tree left the facility with no electrical power for three days. SLAC, a U.S. Department of Energy facility, has now restored all systems needed for the safe operation of the laboratory and normal work resumed on Monday, May 23.
At about 8 a.m. May 18, a 100-foot pine tree, growing well outside the SLAC easement, snapped off at its base and severed two of the three 230 kilovolt transmission lines, immediately halting all electric power to the laboratory. According to Neil Calder, director of communications at SLAC, all staff, except those designated by their supervisors to do essential safety and maintenance work, were asked to stay away from the site during the outage.
All the events that caused the power outage were beyond SLAC's control, Calder said. SLAC's main power lines extend from Skyline Boulevard through the wooded hills west of the laboratory. SLAC maintains a wide easement under these lines, and regularly trims the trees and undergrowth to prevent interference with the lines.
"This is the first time in 40 years that a tree has brought down our power lines in such a dramatic fashion. There have been power outages before but these were normally remedied quickly by restoring the 230 kilovolt or by temporarily switching on to our 60 kilovolt backup line," Calder said. "However, circumstances last week conspired against the laboratory, as this backup line, which comes in from the eastern side of the SLAC site, had been disconnected because of the construction on Alpine Road.
"After tremendous work by Pacific Gas and Electric, working in very inclement weather on the slope of Skyline, power was restored to SLAC on Friday evening. Since that time SLAC teams have been at work implementing a careful, phased restart of our many, complex systems and the laboratory is now ready to return to work," Calder said.
