TVA Power Interruptions: A Historic Event in Region

Submitted by Tri-County Electric CEO, Paul Thompson

Early in the morning on Friday, Dec. 23rd, I received a message that I hoped to never get, said Paul Thompson, Tri-County Electric’s Chief Executive Officer. The notification was that the Tennessee Valley Authority (TVA), our power supplier, was calling for ELCP Step 50. That doesn’t mean much to most people, but to those of us in the power business in this area, it was serious.

The Emergency Load Curtailment Plan (ELCP) is a carefully designed blueprint to reduce system demand when energy use spikes to critical levels. The early steps of the plan include shutting off lights and equipment at our offices, and later steps of the plan call for interruption of industrial plants and large commercial businesses.

This was the first time in TVA’s 92-year history that the agency called for ELCP Step 50, mandatory rolling blackouts. It would be called twice in a 24-hour period.

The events of Friday and Saturday, December 23rd and 24th, were extremely unusual.

Winter Storm Elliot brought record cold temperatures to much of the country in what the National Oceanic and Atmosphere Administration called a “historic artic outbreak.” Tri-County Electric and TVA both set new winter records for energy demand. During the brutally cold weather and record high energy use, TVA had multiple power generation plants unexpectedly go offline. 

The Tennessee Valley region needed more energy than could be generated. When demand exceeds supply, catastrophic damage can occur to the power grid, resulting in long-term and wide-spread power outages.

The quick action of Tri-County Electric employees protected our community and the region from large and extended power outages. Our team implemented ELCP Step 50 to reduce our system load in a controlled fashion. While this resulted in temporary power outages for some of our consumers, the impacts of the event could have been far worse.

It is hard to be good at something that you have never done before, but our line workers, system operators and engineers sprang into action when they were called. Crews went out into extreme conditions to operate equipment and manage the situation. Their efforts minimized impact on families, businesses, and critical infrastructure. 

We are working with TVA to ensure that our community has the energy we need at the moment it is needed. None of us want to be without power, especially during our Christmas holidays. We appreciate your patience and now want to shift our focus on exactly what happened and how can it be prevented in the future. TVA’s meteorologists monitor weather conditions to assist their engineers in forecasting the power generation needs. The load forecast for December 23rd and 24th was under-estimated. TVA typically has enough stand by generation to cover the loss of their largest on-line generation to cover the forecast load. They also have contracts with neighboring generation and transmission companies to purchase additional power in emergency situations. When TVA lost generation from two facilities the stand-by generation could not meet the load and neighboring utilities did not have excess capacity to provide, due to the extreme demands on their systems. For more than 90 years TVA’s procedures have provided safe, reliable power 99.999 percent of the time. We appreciate your understanding during this unprecedented event and I am confident TVA will take the necessary steps to avoid a repeat of this situation.