Cayce, SC (WLTX) - Across the Midlands, some power plants simply froze, which triggered an automated system of rolling blackouts that at one point left thousands of customers without power.
"It's an extensive system that we have at these power plants and it simply froze," said Keller Kissam, SCE&G's President of Retail Operations. "It worked just as it should from an internal protection standpoint. When it sensed and it froze up, it tripped the unit so no more long term damage would occur on the system."
During a rolling blackout protocol, an automated system shuts off power substations which are responsible for sending power to your home.
"You drop that circuit for 15-30 minutes, maybe a little longer, based upon what the load is doing at the time, and then you re-energize it," Kissam said. "There comes the term rolling. They're not out for a sustained period of time, but a momentary period of time until you can get them back up."
The rolling blackout system has been in place for years. While it's updated annually, it's rarely used and does not turn off the power at buildings like hospitals and schools.
"Before we performed the rolling blackouts, we were headed to a historic peak on our system," Kissam said. "With the blackouts, we didn't achieve that. So it's both a combination of demand by our customers as well as mechanical issues that manifest themselves at our power plants."