Are U.S. power generation owner-operators getting better at winterization and freeze protection? According to the Electric Power Research Institute (EPRI), the answer is yes, and not by a small margin.
“Anything that you focus on like that is going to result in improvements,” said Brad Burns, program area manager for Fleet Management and Operations at EPRI.
Burns oversees research in integrated asset management, plant management essentials and cycle chemistry, three areas deeply tied to practical O&M and seasonal readiness. He said owner-operators are now taking winter preparedness more seriously after several years of severe cold events exposed long-standing weaknesses in instrumentation, insulation and plant procedures.
The improvements are measurable. Plants are investing in more structured work management processes, more frequent walkdowns and more robust engineering reviews. New technologies are entering the field. And the strong push from NERC’s cold-weather standard is forcing changes that would not have happened on their own.
But while progress is real, Burns said the job is far from complete. Understanding where plants are most vulnerable and which new tools and practices are helping remains essential as the industry braces for deeper electrification, rising load and increasingly erratic winter weather.
Top Winter Problem Areas
Across North American thermal plants, EPRI sees the same winter trouble spots repeat year after year.
“Sensing lines and instrumentation is probably the biggest one,” Burns said. These small-diameter impulse lines operate in low- or no-flow conditions, making them extremely vulnerable to freezing. Once they freeze, the consequences can be immediate.
“You can’t continue to fire a boiler without drum level. If it sees that there’s no drum level as a false indication, because the sensing line froze, guess what? Unit trip, you’re offline,” Burns said. “And it’s very difficult to get units back online in cold weather.”
Problems almost always trace back to poor insulation and heat-tracing: missing or damaged insulation, improperly installed heat-trace systems, or systems that were never sized correctly in the first place.
Cooling systems also suffer when temperatures drop. Burns cited icing in cooling towers, cooling water intakes and service-water systems, particularly when a cooling-tower cell is taken out of service and freezes solid.
Fuel and material handling add another layer of risk. Coal and limestone systems can freeze, diesel fuel can gel, and natural-gas curtailments during extreme cold create operational constraints even if equipment itself remains functional. Burns noted that more plants are moving to dual-fuel capability to maintain reliability when gas supply tightens.
Even human mobility becomes an operational constraint. Some plants require tire chains, traction gear or specialized cold-weather PPE simply to allow operators to move safely around the site and perform routine duties.
What Went Wrong During Uri/Elliott – And Why It’s Changing
During Winter Storms Uri and Elliott, heat trace systems often failed because they had never been tested under real extreme-cold conditions.
“Of course they test their systems to make sure they’re functional, but not under full load, maximum cold conditions,” said Burns.
In many cases, the only indicator of whether heat trace was functioning was a single LED light – not a true assessment of whether circuits could hold full load without tripping.
“They didn’t have any sophistication in those systems,” said Burns.
He noted that plant management was also reluctant to spend on freeze protection unless they had no choice.
“Let’s be honest here, power plants are not going to spend money on freeze protection systems when they need other critical equipment,” Burns said.
That has been changing since NERC introduced the EOP-012 cold weather standard. The rule requires owner-operators to establish cold-weather preparedness plans, perform seasonal readiness tasks, document deficiencies and prove their units can operate in extreme cold conditions.
As Burns put it, “It forced them to do it.”
The standard has led to improved CMMS usage, pre-season walkdowns, checklist discipline and engineering analyses of winter performance. NERC recently reported early progress in its first annual Cold Weather Data and Analysis report, submitted in October.
Newer Technologies EPRI Sees in the Field
While administrative improvements are important, several notable technologies are emerging that directly reduce winter risk.
One is the growing use of instrument enclosures with real-time monitoring. Instead of relying on spot checks, operators can verify heat-trace performance and enclosure temperatures from the control room.
“Having enclosures for your sensing lines, and having those enclosures monitored in real-time with temperature and things like that, that’s a whole technology that’s emerging,” Burns said.
Another trend is the adoption of guided-wave radar (GWR) for drum-level measurement, particularly in HRSGs with triple-pressure drums exposed to the elements.
“It’s basically a device that’s mounted on a chamber,” Burns said. “It sends low-energy pulses down a probe that’s reflected back up to the device, and it detects the drum level without use of sensing lines.”
These changes align with what Emerson is seeing across the industry. Marty McDonough, senior business development manager for the company’s power business, said utilities are adopting wireless temperature monitoring, acoustic sensors and non-intrusive flow meters at a pace that would have been unlikely a decade ago.
“Once you have a wireless system, then it’s easy to add monitoring points,” McDonough said. “It’s very cost advantageous once the gateways and the system are in.”
Emerson is also seeing structural changes in how drum-level measurement is specified. Historically, GWR was more of a brownfield upgrade. Today, McDonough said HRSG OEMs themselves are requesting it on new projects.
“We actually have the HRSG OEMs coming to us from the experiences of the end user, saying, ‘Hey, we want guided-wave radar here. We don’t want to do wet legs and impulse lines anymore,'” he said.
But despite regulatory pressure and technological progress, Burns noted that budgets remain tight.
“Most plants in the U.S. and North America nowadays, they’re just not swimming in cash,” he said. “They’re being forced to look at every dollar they spend, and those dollars are not going to go towards cold weather preparedness, unless they feel like it’s a real reliability risk or a compliance risk.”
But industry experts say attitudes about cold weather reliability are changing. Severe cold events have forced utilities – particularly in the South – to make winterization upgrades. McDonough said these regions are now among the most proactive in pursuing new monitoring, eliminating freeze-prone wet legs and upgrading heat-trace verification systems.
Those changes can produce meaningful results. Burns pointed to TVA’s performance during Winter Storm Heather in 2024. After significant upgrades and corrective actions, TVA produced the highest weekly energy output in its history with minimal to no events – a stark contrast to its experience during Elliott.
