Last December was the first time in LG&E/KU’s history that it did not have enough energy to meet customer demand.
Temperatures on Dec. 23 reached negative 8 degrees in Louisville and with the wind chill they exceeded -30 degrees. Pipes burst in homes all over the city. High winds and heavy snow canceled tens of thousands of flights across the East Coast. Two people died in Kentucky, and as many as 1.6 million homes lost electricity in what became known as Winter Storm Elliott.
At 5:58 that night, LG&E/KU began turning off the lights. For the next four hours, LG&E/KU implemented rolling blackouts affecting about 53,000 customers.
In the weeks that followed, LG&E/KU officials blamed the power failures on regional natural gas pipeline supply issues. They maintain they had the necessary power generation on hand, and extraordinary conditions impacted their ability to meet customer demand.
Kentucky lawmakers held a hearing on the power failures in early February. Several Republicans blamed the outages on the retirement of coal power plants and the rise of renewable energy. And on Feb. 2, LG&E/KU Chief Operating Officer Lonnie Bellar reassured lawmakers.
“We were ready for the storm,” he said.
New records and testimony from LG&E/KU officials reveal that natural gas disruptions were not the only problems during the storm.
LG&E/KU confronted mechanical failures at coal generating units ahead of the storm, frozen equipment at coal and gas generating units during the storm, and challenges purchasing additional power when other power resources failed.
“So there was not one source of generation that was the sole cause, but rather coal generation, gas generation and not being part of a broader regional transmission organization,” said Sierra Club Attorney Kate Huddleston, who questioned officials last week.
Following that hearing, Republican Sen. Robby Mills of Henderson sponsored a bill that became law making it harder to retire coal-fired power plants. That law is now at the center of a case that could define the future of Kentucky’s energy.
Energy researchers say the failures of fossil fuel generation during the winter storm are further proof of the need to transition to a more diverse portfolio that includes robust renewable energy.
The lead up
The day before the storm, a conveyor used to move coal ash at one of LG&E/KU’s coal generating units in Trimble County stalled. A combustion failure diminished the output at another unit at the Brown Generating station earlier that month, while mechanical issues had stalled power generation at a hydroelectric plant in Mercer County since November.
To weather the storm without interruption, LG&E/KU needed 317 megawatts (MW). The coal and hydroelectric plant failures before the storm started knocked off 444 MW.
LG&E/KU officials testified about the Winter Storm Elliott power failures during a Public Service Commission hearing. The focus of that meeting was the utilities’ plans to retire nearly a third of their coal generation by 2028 and replace it with natural gas, and a smaller amount of renewables.
“Yes, as we have been discussing, had there not been other unit issues at those two facilities during that time period we would not have been required to curtail load,” Bellar testified to utility regulators last week.
If the coal units were firing, there would have been enough electricity to avoid blackouts.
During the storm
At midnight Dec. 23, LG&E/KU had more than enough power to meet anticipated demand. The utility had more than 4,700 MW of power up and running. They also had an additional 7,200 MW they could tap into. But as the day progressed, the freezing temperatures began taking their toll on the power plant equipment and gas pipelines across the region.
The problems began at 1:30 a.m. when a pilot light blew out, tripping offline four natural gas generating units at Brown Generating Station.
Before the sun rose at 7:57 a.m., the cold temperatures briefly took out another gas unit at Paddy’s Run Station, diminished generation capacity at a second gas plant, prevented a third plant from running, and limited capacity at a coal generating unit.
Shortly after 11 a.m. the gas pressure on the Texas Gas Transmission pipeline dropped below minimum requirements, forcing LG&E/KU to limit capacity by hundreds of megawatts from gas units at Cane Run and Trimble County.
At 3:45 p.m., a transmitter on a boiler feed pump froze at another Trimble County coal generating unit, limiting its capacity. Fifteen minutes later, the cold weather forced another equipment failure at a Mill Creek generating unit, diminishing its capacity.
In total, the winter weather knocked off around 380 MW of coal generation and more than 871 MW of natural gas that day. LG&E/KU officials said it was the loss in gas pressure from the Texas Gas Transmission pipeline that dealt the blow to the system ultimately causing the blackouts.
‘Desperate’ for power
That left LG&E/KU scrambling. Here’s the exchange between PSC chairman Kent Chandler and Bellar during testimony.
“You were desperate for power, is that accurate?” Chandler asked.
“Correct, we were looking for all sources of energy to avoid going into curtailing our mode of operation,” Bellar replied.
Around 4:30 p.m. on the 23rd, LG&E/KU requested 400 MW of electricity from PJM, a regional transmission organization that coordinates the movement of wholesale electricity for much of the East Coast including parts of Kentucky. Membership is voluntary, and LG&E/KU isn’t a member. As a result of the extreme demand, PJM did not fulfill the request.
Southern Renewable Energy Association executive director Simon Mahan said that other members of PJM didn’t implement rolling blackouts, including Kentucky Power and Eastern Kentucky Power Cooperative, while both LG&E/KU and the Tennessee Valley Authority, which are not members, did have blackouts.
“But a sticky problem that we've had is this assumption that fossil generation, natural gas and coal in particular, are 100% reliable all the time,” Mahan said. “The reality is they are just like any other large machine.”
The solution is to diversify energy portfolios across a range of resources including solar, wind and battery storage, and across a broad geographic region, he said. That way, when it’s freezing in the Southeast, utilities can rely on power from other areas of the country where the weather is calm.
The takeaway
A spokesperson for LG&E/KU says they’re learning from the events that unfolded that day. They’re now analyzing why the equipment failed, studying the potential for changes to their use of natural gas pipelines, and undergoing upgrades on gas units at the Trimble County Generating Station.
“While we’re always looking to improve upon our performance, as a first-of-its-kind incident within our system, we take the events that unfolded during Winter Storm Elliott seriously,” said Natasha Collins with LG&E/KU. “We have worked with Texas Gas to understand the pipeline issues that occurred and to ensure any necessary changes to processes and procedures are made to prevent a recurrence.”
LG&E’s primary response has been to point to the natural gas pipeline disruptions because those issues were outside their control, said Thom Cmar, a senior attorney with EarthJustice, who is involved in the LG&E/KU case before the Public Service Commission.
Much of the testimony from LG&E officials has been that the reliability issues surrounding coal plants are “ordinary” and were anticipated by the utility. But Cmar said that utilities shouldn’t normalize those assumptions, given that GOP state lawmakers, and gubernatorial candidates like Attorney General Daniel Cameron, are arguing that fossil fuel plants are more reliable than newer, cleaner burning sources of energy.
“And the evidence is clear that that's just not true,” Cmar said. “It seems to be predicated on an assumption that just because we've been getting our energy from these plants for a long time, that makes them more reliable, and that the facts don't bear that out.”
Ultimately, he said, a shift to newer, cleaner forms of energy is a solution to address reliability concerns, not just climate or environmental concerns.
