Preventing Summer ‘Gridlock’

Meeting Summer’s Peak Demands

We’ve all been there: summer travel spoiled by sitting in interstate traffic due to road construction, a stalled vehicle or another type of incident.

Frustrated at standing still, you wonder, “Why is this lane closed now?” or “Why doesn’t someone help us find an alternative route so we can all get moving again?”

If you compare July interstate traffic to the TVA transmission system during peak summer demand climbing above 30,000 megawatts, you can easily imagine the potential for “gridlock” that could damage transmission equipment, force generator derates or even cause power outages.

Fortunately, at TVA there’s a team developing plans to keep electricity flowing efficiently and reliably across one of the nation’s largest transmission systems.

“I think of the power grid like the transportation system,” said Casey King, an electrical engineering planner in TVA’s Reliability Analysis group. “My group helps make sure there are paths available for power to get where it needs to go. Our transmission operators are focused on keeping the lights on from day to day, and my group looks ahead to the future as an extra set of eyes to help them maintain reliability.”

Just like a network of highways and roads, TVA’s transmission lines and substations require maintenance work and upgrade projects, and they can also face emergent equipment issues or events that suddenly take lines out of service.

Hotter temperatures and higher loads put additional stress on transmission lines and their electrical capacity.

“We plan a lot of our transmission project and maintenance outages during the spring and fall, because we want more of our lines in service to maximize transmission capacity during peak demand,” King said. “Our group develops plans and schedules that can support the needed transmission work each year. We avoid overlapping transmission element outages that create reliability concerns, which allows our crews to complete their work safely and efficiently.”

In addition to planned outages, TVA also prepares for unforeseen transmission challenges such as equipment or power line issues, storms, or changes in TVA’s generation mix.

"We plan our system to be reliable under whatever next contingency could come our way,” King said. “The power grid needs to be configured so that if a transmission line or transformer goes out unexpectedly, we are not putting people in the dark or risking damage to the transmission system. Our group studies thousands of contingencies and looks at how we can address issues that might arise."

The TVA Reliability Analysis team builds forward-looking computer models to predict what the transmission system will look like in normal conditions and under stress – such as at peak loads, if major generating units go offline, or if neighboring utilities are transferring a lot of power across the grid.

“We are trying to predict the future, see what the worst-case scenario is and create plans to respond to possible issues or avoid those scenarios altogether," she said.

King, who grew up in Chattanooga and studied electrical engineering at the University of Tennessee at Chattanooga, has had a front row seat to the operations of TVA’s 16,400-mile transmission system since she started as an intern in 2020.

“I used to take electricity for granted,” she said. “Now I see how much it takes to keep the power grid running every day. Across TVA, we are always working a puzzle to keep the system reliable.”

That requires plenty of analysis and technical work, but also effective communication. This teamwork and planning help keep TVA-generated electricity moving reliably each day during extreme summer demand peaks.

If only traffic would move this smoothly on our July family trips to the beach.