When electricity demand is higher than supply, such as during a heat wave, the power grid that serves all of California is put under strain. To prevent large blackouts during these periods, the statewide power grid operators ask Californians to conserve. If we all do our part cutting electricity usage, outages can be prevented. If electricity use remains too high, rotating outages become a possibility. Set thermostats to 78 degrees or higher. Run energy-intensive appliances during early morning or after 9 p.m. Close drapes and blinds to keep rooms cool.
A rotating outage is a series of small outages that relieve stress from the power grid to help prevent a widespread blackout. PG&E’s service territory is divided into areas called “blocks.” Each block is usually made up of several streets. When the state’s grid operator tells PG&E that rotating outages may be required, a number of blocks are put on standby for a shutoff. If a shutoff is needed, power is turned off to selected blocks typically for 1-2 hours. The result is that smaller groups of customers experience shorter outages, instead of a large area being blacked out for a longer period.
PG&E will call, email or text customers letting them know of the possibility of rotating outages. The notification will direct customers to this page to look up their block number and possible outage time. To do so, follow these steps:
All customers will be asked to conserve energy in the hopes of avoiding the outages completely. If that’s not possible, a list of blocks that could have a shutoff will be posted on this page each day.
When the grid is under strain, estimated shutoff times are posted here daily. However, the times are not a certainty because rotating outages will be cancelled or postponed when conservation efforts have been successful. For example, if your block was estimated to be shut off from 4-5 p.m. and a shutoff wasn’t required, your block becomes first on the list for 5-6 p.m. If the 5-6 p.m. shutoff isn’t needed, your block remains first on the list for a shutoff for 6-7 p.m. This continues until the risk for outage passes completely or until rotating outages are implemented.
A typical block number includes a number and a letter like "7C" or "2A," but over 50% of PG&E customers are in outage block 50. Outage block 50 customers share a circuit with a critical facility like a hospital, police station or fire department so they are typically exempt from rotating block outages.
|Block number||Estimated shutoff time|
Blocks not listed are not expected to be impacted.
Times may be cancelled or postponed if conservation efforts are successful.
There are no current plans for rotating outages.
There are no current plans for rotating outages.
If your block is called, you will experience an outage of typically 1-2 hours. Once your outage is over, your block should not be shut off for a rotating outage block again until all the other blocks in PG&E’s service territory have been called. Again, the idea is that we take turns experiencing brief outages to protect against longer and larger outages.
No. Rotating outages are due to supply-and-demand issues statewide. The need for rotating outages is determined by the statewide grid operator, the California Independent System Operator (CAISO), and not PG&E.
A Public Safety Power Shutoff (PSPS) is activated by PG&E to help prevent a wildfire in areas where severe weather and dry vegetation conditions are present.
There are other reasons power can go out. Some outages are planned, and we can provide advance warning. Other outages happen suddenly, and we are unable to notify customers ahead of time.
A Stage 3 Emergency is called when the Independent System Operator (ISO) is unable to meet minimum contingency reserve requirements for electricity and a load interruption (a power outage) is imminent or in progress. These emergencies are declared by the California Independent System Operator (CAISO).
CAISO will typically order the state's utilities, including PG&E, to reduce electrical load by initiating rotating outages in order to prevent larger outages on the grid. Due to the emergency nature of these outages, we may not be able to give advance warning to customers.
In the event of a Stage 3 Emergency, the CAISO lets California's utilities know the amount of energy load (in megawatts) they need to take offline. PG&E then selects the number of blocks in our service territory that, when taken offline, will meet the required reduction in energy.
A typical block number includes a number and a letter like “7C” or “2A,” but over 50% of PG&E customers are in outage block 50. Outage block 50 customers share a circuit with a critical facility like a hospital, police station or fire department so they are typically exempt from rotating block outages.
The CAISO maintains reliability on California's energy system, one of the largest and most modern power grids in the world.
As the statewide power grid operator, the CAISO works around the clock to meet the electricity needs of consumers, while increasing the amount of renewable energy to usher in the clean, green grid of the future.
PG&E, along with the San Diego Gas and Electric and Southern California Edison are participating members in the CAISO, and coordinate on the topics of energy demand and reliability.
Flex Alerts are part of a state-wide program run by the CAISO which manages the power grid in California.
The purpose of a Flex Alert is to encourage customers to conserve as much energy as they can during a designated period. The ISO typically calls a Flex Alert when state-wide forecasts are trending higher than average. Flex Alerts are used to prevent the grid from reaching a Stage 3 Emergency (rotating outages).