FRESNO, Calif. (KSEE) – Friday marks the hottest day yet this year. Not only are the Central Valley’s air conditioners running overtime, but parts of seven western states are also under heat warnings which raise concern for power outages.
Extreme heat is a challenge for California’s electricity grid. Last year, the lights went out multiple times on the hottest days when demand exceeded supply.
PG&E’s Denny Boyles says current infrastructure is based on past conditions.
“They look at historic peak usage at any given day, at any given temperature and they build capacity above that. But when you get into record temperatures that means you’re putting people in conditions they’ve never experienced before. You’re doing the same with the grid.”
Outages may occur for a number of reasons, including public safety power shutoffs in fire-risk areas (during hot, windy weather) or rotating outages if demand exceeds supply (if this happens, special attention is paid to keep the power in at critical facilities such as hospitals).
“One of the most common outages in the heat is going to be transformer failure,” said Boyles. “Transformers are built to have a period of time overnight where there’s not as much demand on them, the weather is a little cooler, they can cool down from the hot temperature they were operating at during the hottest part of the day.”
State regulations require hospitals to have emergency backup power supplies.
Fresno County Emergency Medical Services Director Daniel J. Lunch says hospitals in the county have backup generators – as well as their support services.
“Our dispatch centers, communications centers for emergency services has generator backup and are tested and ready to go.”
Saint Agnes Medical Center actually has its own on-site natural gas power plant, running in parallel with PG&E’s supply. It can also run on its own in emergencies.