Montana wildfires interrupt California power supply

Wednesday is another power watch day in California as the state continues to struggle to keep the lights on. Citing the effects of wildfires burning in the West on electricity supply and transmission, the California Independent System Operator (ISO) called a Stage 1 power emergency Tuesday afternoon, after Bonneville Power Administration shut two kv power transmission lines in Montana to protect them while the fires through.


Wednesday is another power watch day in California as the state continues to struggle to keep the lights on. Some sources expect the crisis to last through September.

Tuesday, citing the effects of wildfires burning in the West on electricity supply and transmission, the California Independent System Operator (ISO) called a Stage 1 power emergency afternoon, after Bonneville Power Administration shut down two kv power transmission lines in Montana to protect them while the fires burned through.

Closing the lines reduced by 1,000 Mw the amount of power that the California ISO was expecting to import from the Pacific Northwest.

Earlier, a wildfire in the Plumas National Forest north of Sacramento had grown to about 20,500 acres early Tuesday, according to the National Fire Information Center, affecting about 550 Mw of generation.

Pacific Gas & Electric Co. reported the fire had also shut down three 230 kv lines. The power lines carry power from hydroelectric turbines in the Feather River canyon watershed.

The ISO said forecasted consumption of electricity was expected to peak at about 38,300 Mw at 4 p.m. Tuesday. At 4:20 p.m. Pacific Standard Time, the load was 38,340 Mw. Earlier in the day, the ISO requested additional supplemental energy bids, of up to 1500 Mw, between 3-7 p.m.

It also was advising the utility distribution companies of potential power shortages and asked them to prepare for imminent implementation of the interruptible load programs and-or the electrical emergency plan.

With hydroelectric facilities producing less power than normal, sources at the California Power Exchange say supplies could remain tight through Sept. 22. Power prices are continuing to bump up against the California ISO's $250 mw-hr cap.

Under the ISO alert system, a Stage 1 alert signifies electricity reserve margins have fallen below 7%; a Stage 2 alert signifies reserves have dropped below 5% and large customers who participate in the voluntary interruptible power program are asked to be shedding load. Under a Stage 3 alert, signaling reserves have fallen below 1�%, rolling blackouts are a possibility.

The state-chartered California ISO is responsible for managing the flow of electricity on the long-distance, high-voltage power lines that make up the bulk of the state's transmission system.

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