California could face rolling blackouts Monday

With demand for air conditioning climbing, California could experience rolling blackouts Monday evening and just barely escaped outages Monday morning, Jim McIntosh, director of operators for the California Independent System Operator, said on a conference call. McIntosh said he is 1,000 Mw short of power to supply the peak, unless Californians leave the air conditioning off after they get home from work.


By the OGJ Online Staff

HOUSTON, May 7 -- With demand for air conditioning climbing, California could experience rolling blackouts Monday evening and just barely escaped outages Monday morning, Jim McIntosh, director of operators for the California Independent System Operator, said on a conference call.

The morning swing caused by an unnamed Canadian supplier who first pulled 1,000 Mw and then returned it about noon, McIntosh said. But even if that supplier stays on line throughout the day, McIntosh said he is still 1,000 Mw short of power to supply the peak, unless Californians leave the air conditioning off after they get home from work.

"Air conditioning will drive the peak," he said. A total of 12,500 Mw worth of generation remained unavailable with power plants off line because of preventive repairs and plant malfunctions.

The ISO declared a Stage 2 electrical emergency Monday at 10 a.m. when operating reserves dipped below 5%. For the first time in several months, McIntosh said, the ISO called on interruptible customers to shed 900 Mw of load.

The emergency is the result of a heat spell with inland highs in the low 90s, causing the surge in air conditioner use, McIntosh said.

He said temperatures in Phoenix, Ariz. in the Southwest, were nearly 100°, limiting imports from that region. Total imports from the Northwest and Southwest were expected to be 4,000 Mw over peak demand, but McIntosh said that forecast is now looking iffy. Imports from the Southwest could be 500-1000 Mw less than originally expected.

Four nuclear units are off line in the western US for refueling or repairs. McIntosh said three are down for regularly scheduled maintenance at a time the state ordinarily can count on hydropower to take up the slack, and one is down after a problem at the plant. The three down for routine maintenance are expected to be back in operation in the 30-40 days.

In addition, 2,000 Mw of generation from the state's qualifying facilities (QFs) remain unavailable to the state's grid.

Demand across the California ISO control area is expected to peak at 32,000 Mw about 3 pm PST. Monday's Stage 2 alert is in effect until midnight. A Stage 2 is called when operating reserves dip below 5% or are expected to within the next 2 hours. If an operating reserve shortfall of less 1.5% is unavoidable, Stage 3 will be initiated and rotating outages are initiated.

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