Jan. 17, 2001Northern California’s Silicon Valley slipped into darkness Wednesday, the first to feel the effect of rotating outages ordered by the California Independent System Operator because of dangerously low electricity supplies.
The California ISO requested Pacific Gas & Electric Co. to curtail 400 MW of power to firm customers and separately asked a municipal utility and irrigation district to cut 100 MW. The outages rotate in blocks of 100 MW that affect about 100,000 customers at a time. The individual outages last about 1 hr. Pacific Gas & Electric said the outages are affecting 320,000 customers.
�In Alameda the lights are off,� says Joe Ronan, a regulatory affairs executive with Calpine Corp. �The Calpine headquarters in San Jose still has lights now. But a lot of San Jose is already cut off.�
This is the first time that rolling blackouts have been required since the grid operation was taken over by the independent system operator in 1998. The power shortage is expected to last all evening and possibly into the next few days.
Very little power is being bid into the California Power Exchange (PX) day-ahead market. Pacific Gas & Electric’s and Southern California Edison Co.’s financial problems appear to be hurting the PX market, said Jim Detmers, managing director of operations. That means the ISO itself must scramble to find the power.
Today at 11:40 a.m. PST, the ISO was unable to find enough power to keep the entire system from collapsing and was forced to order rolling blackouts.
In addition, ISO executives said 11,000 MW of generation are out of service for planned and unplanned repairs.
The state is limited in how much power can be sent North because of a transmission system bottleneck near Bakersfield called �Path 15.� Unless enough power is imported into northern California from outside the state, engineering constraints reduce the amount of power that can be drawn up through the transmission system from the South, Detmers explained in a conference call. As a result, the blackouts were restricted to northern California for the time being.
A spokesman for Gov. Gray Davis said the governors office was in meetings to decide whether to make a statement about the blackouts in northern California.
Bonneville Power Administration, the Northwest’s largest power producer, was sending what it could to California, says Mike Hansen, spokesman for the federal entity.
�We are sending a total of 4,800 MW-hr from 1 p.m. until 10 p.m.,� he says. �That�s about the same as yesterday.�