California Spot Power Surges as Cloud Cover Cuts Solar Output

Wholesale power advanced in California as cloudy conditions cut solar output while demand was higher than forecast

Solar generation on the network run by the California Independent System Operator Corp., covering most of the state, reached 2,654 megawatts at 11:33 a.m. local time, lagging behind the day-earlier levels by 20 percent, data on the system manager’s website showed.

Consumption on the grid averaged 26,647 megawatts for the hour ended at 11 a.m. local time, versus the day-ahead projection of 26,223 megawatts, according to the grid manager.

Power usage on the system is forecast to peak today at what would be a five-day high of 29,478 megawatts.

The low temperature in San Francisco today was forecast to be 45 degrees Fahrenheit (7 Celsius), 1 below normal, while the low in Los Angeles will be 51 degrees, 3 more than usual, according to AccuWeather Inc. of State College, Pennsylvania.

“Energy prices have been elevated in California as higher-than-expected load is occurring concurrently with solar generation coming in 600 megawatts below expectations as of the hour ended 11 a.m.,” said Chris DaCosta, a Boston-based power market analyst for Genscape Inc. who tracks real-time data in the California ISO.

Spot wholesale power at Northern California’s NP15 hub, which includes deliveries to San Francisco, jumped $11.30, or 39 percent, to average $40.50 a megawatt-hour in the hour ended at 11 a.m. local time from the same time Jan. 16, grid data compiled by Bloomberg showed.

Power at the SP15 hub, serving Los Angeles and San Diego, jumped $27.23 to average $35.99 a megawatt-hour for the period.

Power in California’s north hub traded $14.03 more than the south, narrowing from a premium of $16.64 on Jan. 16, and compared with a three-month average discount of 41 cents.

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