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Editor’s Note: This is the second in a series in which Morristown Utilities officials discuss the unprecedented stress a recent cold snap put on the power grid.

At 4 a.m. on Christmas Eve, when the emails started flying and Morristown Utilities staff realized that TVA was implementing Step 50 of the Emergency Load Curtailment Program, MU officials were understandably surprised.

The Emergency Load Containment plan is practiced twice per year by TVA utilities and cooperatives and is compiled of Steps 10-60.

“Since I have been here (1995), we’ve been in Step 40 one time. TVA had never been in Step 50 since it was created,” MU General Manager/CEO Jody Wigington told attendees at the Jan. 4 Rotary of Morristown meeting.

Step 50 is the Interruption of General Load. Had Step 50 not happened, Step 60 would have been implemented.

“That’s where TVA goes in and turns off large substations – like some of ours,” Wigington said, “to keep the frequency from going unstable.”

TVA has, in utility terms, a balancing authority. They maintain plans ahead of time, managing interchange events.

“Incidentally, TVA’s nuclear plants were providing 40 percent of the load – they never slowed; they ran full speed right through the outage,” Wigington said.

Sustainable energy sources did not fare as well.

“TVA absolutely had all of its renewable energy portfolio fully operational – and it generated 0, because the sun doesn’t shine at 5:30 in the morning or, really, when the clouds are here, so that was a problem,” Wigington said.

Parts of Hamblen County are serviced by Holston Electric and Appalachian Electric Cooperative, both of which are primarily made up of residential load.

“They get their load curtailment by curtailing residential, which they did,” Wigington said. “They were able to announce 15-minute rolling blackout intervals.”

Morristown Utilities has a number of large industrial customers that make up the majority of its power load.

“Our plan calls first for our industrial customer friends to reduce power, and they performed excellent to help us avoid curtailment of our residential customers,” Wigington said.

Eventually, the TVA situation necessitated MU to curtail residential use, which resulted in a tactical decision regarding the utility’s board of director’s chairman.

Curtailment means in essence to shut down entire circuits, which can include a mix of service businesses and residences. For example ,one high-load circuit considered for a 15-minute blackout included, along with a large neighborhood, a nursing home facility, a dialysis center and a number of traffic lights along a crucial section of roadway – so that was a ‘no.’

“It was not a good day for the police force to have those traffic lights turned off,” Wigington said.

Another neighborhood consideration included the home of MU Board Chair George McGuffin – “Shut him down,” Wigington told his team.

The timeline began at 5:22 a.m. Friday – or ‘Christmas Eve Eve.’

The temperature was around 10 degrees. TVA went into high alert to specific industrial customers that it communicates with directly. For example, three Hamblen County industries have contracts with TVA, termed ‘interruptible contracts.’ When TVA deems it necessary, they call/contact those three industries and give them a 5-minute warning to reduce their power usage to a pre-determined level as stated in their contract. By volunteering to participate, these three industries along with a number of others within the TVA’s 7-state coverage area receive power credits.

“TVA called them all,” Wigington said.

By 9:17 a.m., TVA had moved to Step 20 of the ELC Program. MU was required to notify the public and request they volunteer to reduce usage via media outlets including the Citizen Tribune, local radio stations and social platforms.

“Very quickly, they were in more trouble,” Wigington said.

At 10:05 a.m., TVA moved to Step 40: Partial Curtailment of Large Firm Load.

“We went to our industrial customers (in addition to those with interruptible contracts) and did some 45-minute interruptions,” Wigington said. “We do longer interruptions for industry; you don’t want to do residential like that because you can’t pick it back up, it’s called a ‘Cold Load Pickup.’ You leave residential customers off long enough, then turn the power back on and everyone’s heat pump comes back up, along with the strip heat, and it’s hard to keep the breakers operational.”

At 10:30 a.m., TVA moved to Step 50, No. 2.

“That means we have to go to 10 percent,” Wigington said. “The interruptible contract industrials came back on for two hours, then they stayed off all the way through Saturday afternoon. That’s a big sacrifice, but they receive a lot of credits on their power bills for having the ability to call that.”

The record was set for TVA power usage on Friday night at 31 megawatts and the next day was about the same.

“We went to bed thinking the probability was ‘medium’ that we’d get into what we got into on Saturday morning,” Wigington said.

“But overnight, coal and gas failed, the contracts with neighboring utilities were cancelled; the load never got down to where it was supposed to, and they were in trouble without us.”

At 6:15 a.m. Saturday, Christmas Eve, the utility was in what Wigington referred to as industrial load and by 6:23 a.m., the status was 10 percent curtailment, which resulted in determining which circuits to turn off for approximately 15 minutes at a time.

“We stayed there until about 11:30 that morning. Then we called the dogs off. There were only a few of the circuits that rotated off more than one time. Our system did pretty doggone good; we had a couple of breakers fail – whether you’re man or machine, you don’t particularly like 6-degree weather, so we had a few little electronics freeze, we had some physical stuff freeze too,” he said.

The bottom line was that the longtime forecast and the load that TVA expected for the day was less than actual.

The three manufacturers with direct TVA contracts that shut down portions of their power loads saved an estimated five megawatts.

“That’s a lot of load that the local power companies delivered for that period of time. Had that not happened they (TVA) would have had to have dropped individual towns and substations and things like that. They would probably have gone industry first.”

Wigington noted that TVA was not the only power program in the country that missed the load projections.

“It wasn’t a disaster. We rotated some outages; we got some industrial customers to help us and we go through it. Not the rest of the country were that fortunate.”

Wigington also noted that TVA’s penchant for review and planning means there will be a lot of meetings in the near future.

“It’s always an honor to speak to you,” he said to Rotary members. “You are leaders in the community. I appreciate your mission in Rotary, what you do to make Morristown a better place. Thank you for your commitment,” he said.

Wigington has been a registered professional engineer for more than 40 years in the utility management sector, having held positions with Tennessee Valley Authority, BASF Corporation, Lenzing Fibers and Morristown Utilities (since 1995). He has served as MU General Manager since 2007. As CEO, he is responsible for managing utility operations of more than $100 million in revenue, providing water, power, wastewater and telecommunications services for the city of Morristown. In 2005, he helped guide Morristown’s entry into retail communications as a fiber-to-home. In 2011, he helped guide the city in the deployment of smart grid infrastructure for demand response and system modernizations.

Rotary President Justin Cook introduced Wigington the Rotary meeting which was at full capacity – meaning extra chairs had to be brought in and the chicken entrée was depleted before later arrivals hit the buffet.

“This is just a great reminder of how fortunate we are to have Jody and Bryan DeLozier leading the effort at Morristown Utility, and their team,” Cook said.