Northern California wholesale electricity prices declined, reversing earlier gains, as demand fell below forecasts.
The California Independent System Operator Inc. issued a Flex Alert for today through tomorrow asking consumers in the northern part of the state to conserve power and the operators of power plants and transmission lines to restrict maintenance. Demand was expected to peak at 48,479 megawatts in the 5 p.m. hour, the most since August 2007.
The National Weather service declared an excessive heat warning for much of California, including Sacramento, Fresno and Bakersfield.
The high temperature in Sacramento, the state capital, was expected to reach 105 degrees Fahrenheit (41 Celsius) today and peak at 107 in two days, according to the weather service.
In Fresno, the temperature reached 101 on June 27 and 109 yesterday, according to the weather service. The record for yesterday was 112 in 1891.
“We are still in a Flex Alert situation today and tomorrow and will be watching conditions closely for Wednesday or until the heat wave breaks,” Steven Greenlee, a spokesman for the California ISO in Sacramento in Folsom, said in an e-mail. “We are concerned about wildfires and so the risks remain with unplanned transmission and generation outages.”
Spot electricity on Northern California’s NP15 hub slid $11.73, or 25 percent, to average $35.83 a megawatt hour for the hour ended at noon West Coast time from the same time on June 28, grid data compiled by Bloomberg showed. The day-ahead price outlook for the hour was $61.88.
PG&E Corp. (PCG) asked its Northern California utility consumers to conserve powers during extreme heat and issued a peak pricing event from 2 p.m. through 6 p.m. today and tomorrow, according to its website. A surcharge is added to customers participate in a peak day pricing program during the afternoon peak-demand period in exchange for credits during other months.
Power consumption on the California grid was 34,644 megawatts during the hour ended at 10 a.m., 3.3 below the day-ahead forecast of 35,839 megawatts for the period, according to the grid’s website.
A 700-megawatt natural-gas fired unit at Dynegy Corp.’s Moss Landing power plant, about 95 miles (153 kilometers) south of San Francisco, didn’t ramp up this morning and may have tripped offline, according to Genscape Inc., which tracks real-time power data.
Katy Sullivan, a spokeswoman for Dynegy in Houston, declined to disclose real-time operations of its plants per company policy, according to an e-mail response to questions.
Southern California’s SP15 hub was down $13.56, or 28 percent, at $34.15 during the hour ended at 11 a.m., below the day-ahead outlook of $55.06.
To contact the editor responsible for this story: Dan Stets at firstname.lastname@example.org