California still under power watch

For the second day in a row the California Independent System Operator Thursday ordered Pacific Gas & Electric Co. to institute rolling blackouts among interruptible load customers in the San Francisco Bay area.


For the second day in a row the California Independent System Operator Thursday ordered Pacific Gas & Electric Co. to institute rolling blackouts among interruptible load customers in the San Francisco Bay area.

PG&E curtailed 300 Mw of interruptible customers beginning at 12:15 p.m. Thursday during localized load shedding to help stabilize the flow of power on the ISO-controlled transmission systems. The curtailments are occurring at various locations in the PG&E service area.

The ISO said the amount of generation unavailable in the area due to repairs increased to 800 Mw Thursday from 488 Mw Wednesday.

Temperatures in San Francisco reached 103� F Thursday. San Francisco has topped 100� F only 12 times in the last 100 years, the ISO said. The hot weather, coupled with some unavailable generation plants, also resulted in forced outages in the San Francisco Bay area Wednesday, which has been under a power watch since Monday.

Friday's peak demand on the ISO-controlled electricity grid is expected to reach 44,812 Mw by late afternoon. The record peak was 45,884 Mw July 12, 1999.

The California ISO is chartered by the state to manage the flow of electricity along the long-distance, high-voltage power lines that make up the bulk of California's transmission system. Following the restructuring of the state's electricity industry, the California ISO's mission is to keep the open market power grid in California reliable, competitive, and accessible.

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