Rolling black out

Temporary interruptions to some electric cooperative power service were implemented this morning as South Carolina experiences unusually low temperatures.

The freezing weather had already raised demand for electricity to high levels, causing utilities to interrupt electricity service to businesses that have previously agreed to such curtailment—known as non-firm load.

“Curtailing electricity—even for short periods like this morning—is the last thing we want to do during the holidays,” said Robert C. Hochstetler, CEO of Central Electric Power Cooperative. “We’re working closely with Santee Cooper and Duke Energy to minimize inconvenience to co-op members while keeping the system sound.”

Central aggregates the power supply for its 20 member cooperatives from several generating companies and diverse sources to reduce its dependency on any one supplier or source. But extremes in weather conditions can stretch all plans.

The cooperatives are operating load control programs in which thousands of members agree to having their water heaters or heating systems turned off for short periods of time without the loss of comfort or convenience. Thousands more members voluntarily participate in the Beat the Peak program in which they get notifications to reduce non-essential electricity use.

“When you have tens of thousands of members agreeing to that action, it makes a difference,” Hochstetler said.

Power generating companies plan for peak system demand, but contingency plans are implemented to maintain required capacity and non-firm load is shed. These “rolling blackouts” are part of a plan utilities use to manage power supply during high demand times. Such emergency outages are necessary to protect the energy grid against longer, more widespread outages.

As the sun rises, solar power is expected to contribute to power supply resources.

“This is just the type of challenge that reminds us that reliability is of utmost importance,” Hochstetler said. “That’s why we’ve been working diligently with other utilities to improve reliability of the system through improved resource planning.”

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Central Electric Power Cooperative, Inc. is a not-for-profit generation and transmission cooperative headquartered in Columbia, South Carolina. It was created in 1948 and is owned by 20 distribution cooperatives. Central and its member cooperatives provide power to approximately one third of South Carolina's population through the only statewide electric system. www.cepci.org