Rolling blackouts sparked by cold weather in Arizona

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PHOENIX – Wednesday morning’s extremely cold temperatures caused a spike in demand for power as residents cranked up their heaters. This increased demand combined with two Salt River Project (SRP) facilities being offline resulted in rolling blackouts throughout the metro Phoenix area.

Patty Likens of SRP said the blackouts were systemwide throughout SRP’s service area.

Likens said SRP was “shedding the load on our end so that people don’t lose power without our controlling it.”

The blackouts were caused by problems related to the cold weather at SRP's coal-fired plants in Springerville and Page in northeastern Arizona, Likens said. The plants were operating at reduced output levels as SRP worked to repair the problems. 

"In the meantime, because we don't have enough generation coming into the Valley, we're shedding loads," she said early Wednesday morning.

Load shedding is essentially power rationing. It’s something utility companies do when the demand for electrical power exceeds the generated capacity that’s available.

Basically SRP took a defined group of customers offline, and then brought them back up while taking down another defined group of customers.

The blackouts happened during Wednesday's morning peak. About 65,000 customers were affected.

According to Likens, the power outages were brief and were not too widespread at any one time. One Mesa resident said his power was off for about 10 to 15 minutes.

“These are short-term outages to avoid the long-term outages,” Likens explained.

Planned rolling blackouts, which are a rarity here in the Valley, are designed to keep the main grid from overloading.

By 8 a.m., the rolling outages had ended and things were running smoothly.