CAISO extends flex alert, restricted maintenance operations on supply concerns

The California Independent System Operator remains under a flex alert and restricted maintenance operations notice because of expected high loads and temperatures across the footprint with gas supply concerns in Southern California.

The alert and notice started Sept. 8 with the flex alert extended until 9 pm Sept. 9 and the restricted maintenance operations notice extended until 9 pm Sept. 10.

Peakload reached 43.591 GW Sept. 8, the highest in a year, according to CAISO data.

"The ISO is predicting an increase in electricity demand, primarily from air conditioning use," according to a Sept. 8 ISO statement. "The increase can stretch electricity supplies thin and cause strain on our power grid, especially in the late afternoon and evening, when solar production goes offline and wind generation is uncertain, however, temperatures and electricity demand remain high."

There is more natural gas being used than scheduled. SoCal Gas is showing estimated receipts of about 2.4 Bcf/d, with sendout above 2.8 Bcf/d, so storage draw is more than 400 MMcf/d, and it will probably need to pull gas from Aliso Canyon, which usually implies very high prices, said Morris Greenberg, senior manager of North American Power for S&P Global Platts Analytics.

Weather worries

CAISO forecast peakload around 42.871GW Sept. 9 before sliding to 40.065 GW Sept 10.

Temperatures in the Northern California inland region are forecast as much as 10 degrees higher than normal, according to CAISO. In Southern California, temperatures are expected to be 5-10 degrees higher than normal through the weekend, primarily for the interior, although coastal regions are forecast to see some warming as well.

Above-normal temperatures throughout much of the interior western US are also expected this week, with some cities seeing a potential for record-breaking heat, according to CAISO. Widespread heatwaves affecting other western states limit CAISO's ability to import energy from neighboring power grids.

Record-high temperatures are possible at numerous locations across the interior western US Sept. 9, according to the US National Weather Service.

"The persistent dry weather, together with gusty winds, will continue to raise the fire weather threat and poor air quality from the interior Pacific Northwest to the northern Rockies and into the central High Plains," according to the weather service. "Excessive heat warnings and heat advisories remain in effect over portions of the Mojave Desert as well as parts of the interior valleys of California. Changes are on the way as an upper-level trough is forecast to slide into the Pacific Northwest" Sept. 10.

Price impact

The increase in demand and supply concerns drove up power prices across the region.

SP15 on-peak day-ahead locational marginal prices reached $231.30/MWh for Sept. 9 delivery, the highest since the February winter storm drove up prices, according to CAISO data. In comparison, SP15 on-peak day-ahead reached a record of $697.91/MWh for Aug. 18, 2020 flow days after the ISO's back-to-back rotating outages, the first since 2001.

LMPs so far this month have averaged about $86.75/MWh, 67.2% higher than the five-year average during the same period.

Real-time five-minute interval prices were near $80/MWh around 10 am PT Sept. 9, according to CAISO data.

In the Southwest, Palo Verde on-peak day-ahead reached $309.60/MWh for Sept. 9 delivery, a nearly three-month high, according to S&P Global Platts pricing data. In the Northwest, NOB on-peak day-ahead reached $300/MWh, the highest since a heatwave drove up prices in late July.