SALT LAKE CITY & ST. GEORGE, Utah — Power companies across Utah said they were keeping a close eye on their systems this week as the extreme heat is putting stress on the electrical grid.

“Our system is really sensitive to temperature,” said David Eskelsen with Rocky Mountain Power. “So when it gets to be 100 degrees, and the cooling isn’t below 70 at night, that’s when our peak demand happens.”

Most of the power being used during the heat wave will go to running air conditioners at homes and businesses, Eskelsen said. The summer daily demand peaks in the late afternoon and early evening.

Eskelsen said crews with Rocky Mountain Power prepare all year for extreme summer weather by maintaining or expanding generation and transmission systems. The company also focuses on forecasting peak demand and having reserve power available.

“The point is to be ready before the hot weather happens,” he said.

During the heat wave, Eskelsen said Rocky Mountain Power wasn’t expecting any problems in Utah, but still has extra staff on standby and crews monitoring potential problem areas.

Customers can help, he said, by turning up the thermostat to 78 degrees.

“We’ve spent a lot of time and effort making the right investments in the system to be able to weather these hot periods of time,” Eskelsen said.

If there are any outages this week, Eskelsen said they would most likely be isolated to small areas having specific equipment issues. Rolling blackouts — like California saw last summer and Texas experienced in February — would be a last resort and only used in the event of a major equipment failure or loss of a main transmission line.

In southwest Utah, the power department for St. George prepared for even hotter temperatures with little relief during the overnight hours.

“When we have several days that are going to be in excess of 110 degrees, which is what we’re expecting this week, the system itself that serves the entire county is going to be stressed,” said Rene Fleming with the St. George Energy Department.

To avoid outages and encourage conservation, the city and Dixie Power have implemented a new, color-coded system to alert residents about the level of strain on the electric system.

Under the “Use Less, Save More” program, residents will be alerted daily as to what level of conservation is needed, using green, orange or red.

“If it saves money on your power bill, it’s good for you,” Fleming said. “If it also helps limit the stress on the grid, it’s good for all of us.”

Fleming said orange days were expected this week.

Under the orange level, residents have been asked to grill outside, instead of turning on their indoor oven, and to avoid using large appliances during the afternoon and evening hours.

“Particularly during the peak hours from 3 p.m. to 7 p.m., we’d really like people to curb their electric use,” Fleming said.