California still battling power shortages
California is still struggling to keep the lights on after customers voluntarily cut demand almost every day last week. With a less than 7% reserve margin, the California Independent System Operator (ISO) called a Stage 1 emergency at 5:30 a.m. Monday. Expected demand appears to come close to the state�s available state generating capacity and potential imports.
Ann de Rouffignac
California is still struggling to keep the lights on after customers voluntarily cut demand almost every day last week.
With a less than 7% reserve margin, the California Independent System Operator (ISO) called a Stage 1 emergency at 5:30 a.m. Monday. Expected demand appears to come close to the state�s available state generating capacity and potential imports.
If the reserve margin dips to 5%, prospects for a Stage 2 are high. The ISO will have to ask utilities to cut power to customers on interruptible load tariffs.
Peak demand is forecast at 33,718 Mw, and 12,000 Mw of the state�s 38,000 Mw are out of service, according to Stephanie McCorkle, California ISO spokeswoman.
Sources knowledgeable about the California markets say some 5,000 Mw are out of service due to unplanned outages. Another 2,000 Mw is not available because low rainfall has reduced hydroelectric output in the state.
Ordinarily, California relies on as much as 8,000 Mw of imported power to supplement the short generation in the state. But the Pacific Northwest which produces the bulk of the hydroelectric power exported to California is having a dry spell.
�We have the fourth driest November in history. The stream flows are way down,� says Mike Hansen, spokesman for the Bonneville Power Administration (BPA), a federal nonprofit agency that owns and operates generation and transmission in the Northwest.
�The winter reliability question is heating up,� says Hansen. He says BPA doesn�t have much excess power to sell to California because of the unexpected weather conditions in the Northwest region.
McCorkle concurs. �Imports are substantially cut,� she says.�The Northwest is looking at slim reserves. It�s been dry up there, too.�
In addition, the Diablo Canyon nuclear plant is still not up to full power after its refueling outage. San Onofre, another nuclear unit which was offline, is back in service. However, Unit 2 of the Palo Verde nuclear plant in Arizona tripped off line unexpectedly this weekend.
Arizona is a big exporter of power to California. With Palo Verde 2 at reduced output, less power will be available for export. Palo Verde is recovering and holding at 46% power, according to the US Nuclear Regulatory Commission.
Short supply, high demand, and reduced imports are keeping California power prices high. In the day-ahead market, they averaged $206/Mw-hr comparable to last week's prices, says Jesus Arrendondo, spokesman for the California Power Exchange.
�Prices are just going crazy again,� he says.