California averts blackouts; braces for more problems

After narrowly averting rolling blackouts Monday, the California Independent System Operator (ISO) braced for another day of high temperatures and short supply Tuesday. The ISO said demand is projected to peak today at 44,827 Mw, just 57 Mw short of the record set July 12.The ISO declared Tuesday a power watch day and urged energy conservation from California residents as the heat wave in California and the western US continues for a fourth day.


After narrowly averting rolling blackouts Monday, the California Independent System Operator (ISO) braced for another day of high temperatures and short supply Tuesday. The ISO said demand is projected to peak today at 44,827 Mw, just 57 Mw short of the record set July 12.

The ISO declared Tuesday a power watch day and urged energy conservation from California residents as the heat wave in California and the western US continues for a fourth day.

The appeal comes on the heels of an extremely difficult day when energy consumption nearly exceeded energy availability, challenging the power grid, according to state officials.

The agency, which manages most of the California grid, got emergency electricity supplies from the federal Bonneville Power Administration and the Western Area Power Administration to help supply Monday's peak power demand and avoid a Stage 3 emergency.

If power reserves drop below 1.5%, the ISO moves to Stage 3, directing utilities to "drop load," necessitating controlled, involuntary rolling, or rotating, outages for groups of customers across their service areas until sufficient reserve levels are achieved.

To achieve load reduction during Monday's Stage 2 crisis, the ISO directed Southern California Edison Co. to reduce its electrical load by 2,500 Mw, enough power to serve about 2 million homes. Other state utilities were also directed to shed all interruptible load. Under the voluntary load curtailment program, large industrial, commercial, and agricultural customers, as well as customers on SCE's air conditioner cycling program, agree to have their power temporarily interrupted in exchange for reduced rates.

If blackouts had been ordered, it would have been the first time the ISO issued a statewide order to cut off homes and businesses to protect high voltage electrical gear and prevent a breakdown of the entire grid.

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