California’s electrical power grid may be tested like never before, officials warned on Monday, as they urged the public to ramp up conservation efforts or face the prospects of losing power during a historic heat wave that isn’t done roasting the state.
The forecasted energy load on California’s electrical infrastructure exceeds what state officials expect to have at their disposal on Labor Day. And Tuesday is anticipated to be even worse.
That’s when electrical demand is expected to be the highest ever, California Independent System Operator President and CEO Elliot Mainzer said at a Monday news conference.
“The forecast for Tuesday would be above the highest demand ever,” he said. “Right now our goal is to not see that number.”
To keep demand from exceeding the state’s supply, Mainzer stressed that consumers would need to increase their electrical saving efforts two to three times what they did in the early days of the historic heat wave.
State officials anticipate needing 48,817 megawatts of electricity Monday, which would leave the state with a 2,000 to 4,000 megawatt deficit, Mainzer said. He said the projected shortfall has created “the highest likelihood of rotating outages we have seen so far this summer.”
The forecasted deficit led the grid operators to declare a Stage 1 energy emergency alert Monday morning. They also announced a Flex Alert for the sixth straight day, calling for consumers to cut their electricity use. So far it’s worked, as California residents have saved 600 to 700 megawatts in recent days.
State regulators extended Monday’s Flex Alert by an hour, covering 4 p.m. to 10 p.m., and asked consumers to avoid running appliances, set thermostats to 78 degrees or higher and turn off all unnecessary lights during those peak hours.
At about 2:30 p.m. Monday, the energy market will close and grid operators will have a better idea of what to expect for the evening hours. If resources dip too low, energy regulators could initiate a Stage 2 emergency, which would cause the state to dip into its emergency power reserves, electricity from last-minute imports and generators. He estimated the state has about 3,000 megawatts as backup, which provides a small “buffer.”
If a Stage 3 is reached and power must be cut, state regulators will ask utilities to determine the best way to drop their usage, likely rotating across systems, hopefully for short durations, Mainzer said.
“Rolling blackouts are a possibility today,” he said.
On Tuesday, the state is predicting a 51,000 megawatt load, the highest ever for the state. The highest electrical load ever drained by Californians was 50,270 megawatts on July 24, 2006.
Fortunately, the Pacific Northwest has avoided the heat spell, which has allowed California to import some power from that region. Utilities have agreements to share power during emergencies, Mainzer said.
California grid operators are monitoring wildfires to make sure they don’t damage generators or transmission wires. Several generators are already offline, tightening electrical supplies.
This week’s heat wave is expected to last through Friday with daytime temperatures forecasted to be 10-20 degrees above normal. Early Monday morning, around 3 a.m., temperatures still remained in the 80s to low 90s in some inland portions of the Bay Area. The National Weather Service extended an excessive heat warning and heat advisory through Thursday 8 p.m. Conditions are dangerous to those vulnerable to heat and without access to cooling and hydration.
State officials suggest consumers pre-cool their homes with air conditioning during the day, when electrical demand is not as high.
Severin Borenstein, a UC Berkeley professor of energy and member of the ISO’s governing board, noted on Twitter that it wouldn’t take that much for the public to avert blackouts.
“Today looks tough tomorrow looks really tough,” Borenstein tweeted. “But reducing system demand by even 10% would virtually eliminate any concerns.”
Matthias Gafni is a San Francisco Chronicle staff writer. Email: matthias.gafni@sfchronicle.com Twitter: @mgafni
