PG&E is encouraging customers around the Bay Area to prepare for excessive heat on Friday that could contribute to power outages.
PG&E spokesperson Tamar Sarkissian said in an email that this could be an "all-hands on deck event," and said crews will be out and ready to respond to heat-related outages.
Sarkissian said the statewide utility manager, California Independent System Operator, could make the determination to issue a "flex alert," which is a notice to encourage customers to voluntarily reduce power consumption.
According to CAISO, most flex alerts occur in the evening hours when solar energy is less available and many residents are returning home and use more electricity.
Sarkissian said transformer failure is the main cause of outages during excessive heat. Transformers help distribute power from the grid to homes and businesses, and require time to cool down, especially at night, she said. When temperatures stay high overnight, the components in the transformers can become overheated and fail.
Transformers can fail more often in coastal areas with more moderate average temperatures, because many inland areas have equipment designed to handle hotter weather.
If the power does go out, PG&E officials recommend having a fully charged cellphone, as well as flashlights, radios, and batteries nearby. People should unplug all electronics besides one lamp to alert when the power is back on, and then turn appliances on one-by-one when the power is restored.
The utility also recommends that residents place extra ice inside their freezer and refrigerator and keep the doors closed; and that they make sure any generator is installed by a licensed professional.
PG&E crews receive regular heat safety tips, especially before working during a heat event, according to Sarkissian. Co-workers are trained in first aid and monitor each other for signs of heat exhaustion, cramps, or stroke. Crews are to stop working if they recognize these signs.
Temperatures in the East Bay and further inland could reach into the lower 100s on Friday, according to the National Weather Service.