Rotating blackouts could be imminent and more power shutoffs might be needed Tuesday and Wednesday due to extreme heat and high winds, energy officials warned.
The California Independent System Operator (ISO) declared a Stage 2 emergency order Saturday around 6 p.m., meaning that rotating blackouts throughout the state could be expected if people didn’t conserve energy from 3 to 9 p.m. The grid operator had previously issued a Flex Alert, asking customers to conserve energy from Saturday to Monday during a statewide heat wave in order to not overpower the grid system. The conservation of energy helps the power grid maintain reliability during the heat wave, according to ISO.
The ISO said the grid system is strained due to a loss of 1,600 megawatts of power — roughly equivalent to the amount electricity to power 1.2 million homes. The loss of power was from a combination of fires, high temperatures and load on the system. After 9 p.m., the ISO reported there were no blackouts.
PG&E also warned customers Saturday that a “Public Safety Power Shutoff,” might be needed Monday and Tuesday to help prevent wildfire danger. The warning is due to an offshore wind event expected late Monday night through Wednesday morning, the public utility announced Saturday afternoon. The conditions could require a power shutoff since high temperatures, extreme dryness and record-high winds throughout the state could cause sparks that can lead to major wildfires.
“We only use PSPS as a last resort when weather is so severe,” said Katie Allen, PG&E spokesperson on Saturday.
The shutoffs are used to reduce public safety risks in specific geographic areas when a combination of adverse weather and dry fuel conditions are present, she said.
The shutoffs are different than rolling blackouts, or rotating outages, as those are called by the state grid operator, ISO, when there is too much demand for energy statewide, and not enough resources to meet that demand, Allen said.
Since moving to Stage 2 Saturday night, ISO said it could no longer provide expected energy requirements, meaning blackouts could be imminent throughout the state.
Labor Day weekend temperatures are up 15 to 25 degrees above normal for the state during this time. The grid operator is expecting an increase in electricity demand, mostly from air conditioning use.
“Consumers should always be prepared for potential power outages, both planned and unplanned during heat waves, especially in high temperatures that last multiple days,” the ISO said in an advisory Saturday.
Several wildfires throughout the state are also a concern as the fires themselves can take out transmission lines or cause lines to be shut down for the safety of firefighters in the area.
Zones that are under a warning for the power shutoff Tuesday and Wednesday include the Bay Area, although PG&E did not specify which areas would be affected and to what extent. Customers affected would be notified 48 hours before the event via formal notification via text, email or phone calls, Allen said.
Hot and dry conditions are expected throughout the state, with a peak in the heat on Sunday, PG&E said. Temperatures during the holiday weekend are expected to reach triple digits, within the 105 to 112 degrees Fahrenheit range.
The offshore winds are expected around Monday, directly on the heels of the weekend heat wave, which could exacerbate fuel dryness to critical levels, according to PG&E.
The National Weather Service issued several fire weather watches across the state, which are likely to be upgraded to red flag warnings, according to the utility.
PG&E’s public safety power shutoff could occur as a result of several factors: including a red flag warning, low humidity, forecasted sustained winds above 25 mph and wind gusts in excess of 45 mph, and dry material.
A “Spare the Air” alert in the Bay Area was also extended through Monday, due to the unhealthy smog.
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