The California Independent System Operator on Aug. 31 issued a heat bulletin in anticipation of persistent above-normal temperatures and increased electricity demand this week in much of California and the West.
The above-normal temperatures and increased electrical demand were expected across California and the West over the Labor Day holiday weekend, intensifying through this week.
Temperatures in California were forecasted to be 6 to 12 degrees warmer than normal on Wednesday, Sept. 4 and Thursday, Sept. 5. The hottest days across the West are forecasted to be Sept. 4 through Sept. 6, with the warmest temperatures predicted for California, the Pacific Northwest and the Desert Southwest.
California ISO forecasters are carefully watching the middle to latter part of this week as the demand for electricity is expected to increase on those days due to high temperatures and air conditioning use.
The ISO has issued Restricted Maintenance Operations for Wednesday, Sept. 4, through Friday, Sept. 6 from noon to 10 p.m. each day, due to high loads and temperatures across the state. During the RMO, market participants are cautioned to avoid scheduled maintenance to ensure all available generation and transmission lines are in service.
"At this time, the grid is stable and we continue to monitor conditions carefully. While no supply shortfalls are anticipated, it is important to emphasize that extreme heat that lingers for many consecutive days can overtax generators running at high outputs for long periods, increasing the risk of outages and reduced generation. Wildfires can also pose a threat to generators and transmission lines," CAISO said on Aug. 31.
And the hotter weather, since it is also expected to affect other Western states, could limit the potential for importing energy.
The ISO will provide updates as necessary. If weather or grid conditions worsen, the ISO could issue a series of emergency notifications to access additional resources and prepare market participants and the public for potential energy shortages.
The ISO said it could also issue a Flex Alert encouraging consumers to voluntarily reduce electricity use from 4 p.m. to 9 p.m. on certain days. Flex Alerts are typically issued for the subsequent day based on day-ahead market outcomes.
