TVA investing millions to prevent future rolling blackouts

Dec. 19—Just over a year ago, rolling blackouts caused disruptions locally and across seven states when TVA had to reduce its power load in response to Winter Storm Elliott and unusually low temperatures, but TVA officials believe steps taken since then will keep it from happening this winter.

"Because of the lessons learned, we are better prepared to act well in advance of approaching inclement weather," Tennessee Valley Authority Power Operations Emergency Response Program Manager Howie Rose said. "We have revised the cold weather plan for every plant with additional actions to prepare for inclement weather. We have also practiced these plans in the form of tabletop exercises to simulate the conditions and further increase our winter readiness."

TVA spokesman Scott Fiedler said last year's rolling blackouts were the first in TVA's 90 years of operation. There was one set of blackouts on the afternoon of Dec. 23 and two the morning of Dec. 24. Fiedler said they were in 15-minute increments over about a three-hour period.

"If you were affected, it would be for 30 minutes throughout that incident," he said. "It was done in order to maintain system integrity and ensure that the grid was not affected and so that everybody can have power. We did it just to minimize the impact to the public, also ensuring that we can continue to operate a stable electric grid."

Fiedler said Winter Storm Elliot was a once in a generation storm and TVA had never seen anything like it.

"Every power company basically east of the Rockies was struggling just because the scope and speed of the storm was so severe," Fiedler said. "What we saw at the TVA system is this exceeded some of the design capabilities of some of our plants — coal plants and also gas plants."

The storm exposed the vulnerabilities of some TVA facilities.

"Most people don't realize that many of our assets, especially natural gas plants, have vital systems that are located outside which make their critical components more vulnerable to freezing temperatures," TVA Generation Services Senior Manager Jason Garrison said.

TVA shares power with sister companies, Fiedler said.

"At that point there was no more power to be shared across the entire system. We saw that and we decided to implement rolling blackouts, or load curtailments," he said. "Did it go as smoothly as possible? No. There are some opportunities for us to improve and we spent this last year, this last summer, improving on that, drilling on it, training on it to ensure if this were to ever happen again, we know what to do, when to do it, how to do it so we can alert the public sooner."

Fiedler said there were blackouts across all of the seven states TVA serves.

"We worked directly with the local power companies to alert their customers, but it happens very quickly," he said. "Our instructions to the local power companies were to curtail load, which resulted in what is normally called a rolling blackout where the local power company reduces that load section by section, not to impact everybody." — Local impact

Decatur Utilities spokesman Joe Holmes said during the blackouts DU had 26,842 customers. He said TVA required a 10% load reduction from DU on Dec. 24, which affected about 15,000 customers. Not including circuits feeding local hospitals, Holmes said, DU has 52 circuits that were included in the planned rotation, but only 32 circuits were affected before the load curtailment was ended by TVA.

"The remaining 20 circuits would have been taken out of service for 30 minutes had the curtailment continued. The process would have then started over," he said. "Large industry was also curtailed. DU also ran its water and wastewater treatment plants on generators during the curtailment in order to reduce the impact on customers as much as possible."

Holmes said TVA gave DU a 30-minute warning. DU has been working on its own plans since the blackout.

"The DU Electric Operations and Management Team held meetings to review the response," Holmes said. "As a result of those meetings, we have developed a revised plan for implementing scheduled interruptions dependent upon the percentage reduction TVA calls for."

Ken McGee, Joe Wheeler EMC engineering director, said at the time of the blackouts they had about 43,000 customers. He said on Dec. 23, TVA asked Joe Wheeler to reduce its load by 5% and about 4,750 customers were affected. On Dec. 24, they were asked to reduce their load by 10% and about 33,850 customers were affected.

"(TVA) called and basically said, we have to cut back this percent of your total load right now," Joe Wheeler EMC spokesman Michael Cornelison said. "There's a lot of industrial stuff that you can't just turn the power off and they had already ramped down their power usage for Christmas holiday."

Because they were unable to cut the power to the industries, they had to look elsewhere.

"Our engineers started looking at different circuits on our system that we could shut down," he said. "So, if we shut down this circuit and this circuit, that will give us the 10% we needed and then we started looking at, when this one comes back up in 30 or 15 minutes, we need to shut this one down. So, it was really an on-the-fly, sit in here at the office while the engineer's looking at what kind of load each circuit had on it and where we need to pull from."

Cornelison said they tried to spread the blackouts around to different customers as much as possible. There was very little warning from TVA, he said, especially on Dec. 23.

"We were not expecting it at all," Cornelison said. "Everybody was off, we just had our on-call crews because it was holiday weekend; we had to get everybody back in here to the office. So, by the time I got the call, and everybody got back in the office, it was already happening."

Cornelison said they were somewhat taken by surprise on Dec. 24, too.

"They did tell us that if they needed to do it the next day that it would start early in the morning," he said. "They said it would start around 5 a.m. or 6 a.m. and they said they would let us know. Well, they called us at 4 a.m. and said they were having to do it now."

Joe Wheeler has revised its plans, Cornelison said, to make sure they are not caught off guard in the future.

Fiedler said TVA learned from Winter Storm Elliot.

"Right after the storm we had 250 actions that we took. Everything from training, designing, redesigning plants to withstand an Elliot-style storm," he said. "So, we looked at that, we've completed those tasks, we've invested $8 million just this year alone, and then we're planning to invest another $35 million next year to strengthen those plants even more."

Fiedler said TVA has learned what items need to be hardened, heated and sheltered at their coal and gas facilities.

"We've added additional heat tape around critical infrastructure and critical sensors, we've built shelters to trap heat in because in our climate, we have two seasons really, hot and cold. In the summer we're trying to get rid of heat, in winter we're trying to keep it in," Fiedler said. "We've also deployed real-time sensors on critical equipment, so if we're seeing temperatures fall, we can immediately send plant personnel out to check that. We didn't have that before."

He said that TVA is also working to increase its capacity, both to accommodate growing demand and to be better prepared for weather events like Elliott. TVA will have to double or triple their system, Fiedler said, by 2050. Between now and 2029, TVA plans to add 3,800 megawatts of capacity at new and existing gas plants.

"We're building additional energy storage, solar and gas," Fiedler said. "We're investing $15 billion over the next three years to add additional capacity. ... That's kind of over the next three to five years that you're going to see additional capacity come online to prepare for things like an Elliot or any other type of natural disaster that needs the resiliency from a kind of holistic approach, gas, nuclear, hydro and solar."

Fiedler said TVA is looking at potentially building small modular reactors which are not as large as Browns Ferry Nuclear Plant. Fiedler said they are also looking at building a pump storage facility in Jackson County which would be a 1,600-megawatt facility.

Fiedler said there is no guarantee that there will never be another rolling blackout.

"What I can guarantee is that we've done everything possible from what we've learned from Elliot and what we're doing in the future to reduce any chance of any type of rolling blackouts," he said.

With the improvements so far, Fiedler said, TVA's facilities can now withstand a 20-knot wind speed and minus-20-degree weather for 48 hours.

"I think we're ready. We've invested the time, taken the learnings from what we saw at Elliot and applied them into our plants," he said. "We were able to meet record demands in August. Your power system is secure, and we believe that we're ready to deliver energy this winter, keep everybody warm and safe."

—erica.smith@decaturdaily.com or 256-340-2460.