Despite Heat, CAISO Says Gen Looks Ample

By Published On: May 15, 2014

This week’s heat wave marked the first major test of the state’s grid for summer 2014, when the California Independent System Operator says more solar energy and slightly above-normal hydropower from the Pacific Northwest should prevent blackouts. That is, barring any cascading equipment failures that could be caused by wildfires. “The ISO currently has adequate supplies to meet the forecast load, and barring any extreme events, such as wildfires, and other unusual transmission or generation outages, we are not forecasting any problems in the ISO area this week,” said grid operator spokesperson Steven Greenlee at the outset of the heat spell. “But we are constantly monitoring conditions and will make any notifications as needed.” Real-time wholesale prices stood above $80/MWh at press time on the hottest day of the week, May 15. Looking ahead this summer, generation capacity margins are expected to be well above the California Public Utilities Commission’s minimum level of 15 percent, the grid operator found in its summer outlook. The grid operator forecasts a system-wide operating reserve margin of 23.8 percent under normal summer weather. Operating reserve margins are expected to be even higher, at 28.2 percent south of Path 26, although a bit lower, at 22.7 percent north of Path 26. Under a one-in-ten hot weather scenario—which the grid operator considers to be extreme weather—the system-wide margin is expected to drop to 13.6 percent, with a larger 15.1 percent south of Path 26 and just 7.6 percent north of Path 26. The May 9 outlook noted these levels are still above the 3 percent level when the grid operator requires mandatory load shedding. The area once served by the closed-down San Onofre Nuclear Generating Station faces another summer of reliability challenges, according to the grid operator. The agency noted it may need to rely on flex alerts—that is, appeals for voluntary conservation—and on demand-response programs in the area to avoid blackouts. “Voluntary conservation is better than people losing power when demand outstrips supply,” stated Steve Berberich, the grid operator’s chief executive officer. The outlook came just ahead of this week’s heat wave, when temperatures exceeded 100 degrees in many inland areas and pushed or busted records along the coast, including in San Francisco. Peak demand during the week was expected to soar to more than 40,000 MW in grid operator territory on May 15, but more than adequate power reserves remained available. This week’s soaring temperatures are likely a precursor of what’s in store for the state this summer, according to the National Weather Service. Above-normal temperatures are expected from June through October, according to the weather service’s long-range forecast. Water for hydroelectricity is in short supply too, according to the grid operator. In-state hydro capacity is expected to be as much as 22 percent lower than normal, — a reduction of 1,370 to 1,669 MW — and three Northern California thermal plants with combined capacity of 1,050 MW may have to shut down later in summer due to a lack of cooling water supply because of the drought, the grid operator observed. Yet, almost 1,900 MW of new capacity that’s come online over the last year—much of it solar—and imports—including a bit more hydropower from the Pacific Northwest—should make up the shortfalls.

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