Why Xcel Energy is increasingly turning to power shutoffs during strong wind events

This article is an update to a story originally published in February of 2025. You can read the original report here.

DENVER — Xcel Energy issued a warning that it may shutoff electricity in the Denver-Boulder-Fort Collins region Wednesday, December 17 due to projected strong winds. This would mark the second time ever that Xcel preemptively deenergized power lines in Colorado.

The National Weather Service issued a red flag warning and forecast winds up to 80 miles per hour. The wind comes during an unseasonably warm and dry December and during a time of severe drought in many parts of the state, making wildfire a greater risk.

Over the past few years, electric utilities have ramped up wildfire mitigation efforts to prevent their equipment and infrastructure from becoming the source of an ignition.

 

“For over 100 years, the motto had been: reliability first, no matter what. Keep the lights on,” Anne Sherwood, former area vice president of wildfire mitigation policy at Xcel Energy told Rocky Mountain PBS last January. The company is the state’s largest electric utility providing gas and electric power to approximately 230 communities.

 

“Now because of the way things have evolved and the way that risk has increased, there are times when the conditions are to a certain threshold that public safety outweighs reliability. This new normal has been one of our biggest challenges,” Sherwood said.

The December 2021 Marshall Fire in Boulder County, Colorado’s most destructive in terms of number of homes lost, ignited in part from an alleged faulty ignition line. 

Investigators found that a sagging power line managed by Xcel Energy became disconnected amid fierce winds, sending sparks into the surrounding vegetation that were highly flammable following six months of drought. 

The fire ultimately consumed more than 1,000 homes and killed two people.

 

To understand the role that electric utilities play in the state’s growing wildfire-prone landscape, Rocky Mountain PBS spoke with Sherwood; Curtis Hartenstine, wildfire mitigation program manager at Tri-State Generation and Transmission (G&T); Kyri Baker, associate professor of engineering at UC Boulder; and Rebecca Samulski, executive director of Fire Adapted Colorado.

When the conditions are extreme enough, some electric companies have the ability to shut off power in certain areas to prevent an ignition.

 

This has been common practice in California since 2008 and in parts of the golden state, residents experience between four to five shutoffs a year.

 

Xcel Energy implemented a public safety power shut-off for the first time in Colorado in April 2024 to much criticism. Complaints included a lack of advanced warning and inaccurate information. 

The shut-off, which occurred primarily in Boulder County and affected 55,000 customers, lasted up to two days for some people. Jails, emergency services, pharmacies and restaurants scrambled while individuals with certain medical conditions, such as those that rely on oxygen tanks, were left vulnerable.

 

“We really learned a lot of lessons from the April event,” said Sherwood.

 

Kyri Baker, associate professor of engineering at UC Boulder said utilities view shut-offs as a last resort. 

“It becomes life and death with electricity, so they want to not do it if possible.”

 

However, Sherwood said they will likely be doing more in the future. 

“The odds are favorable that we will be doing more given weather conditions, drought conditions and humidity.”

 

Power lines can cause wildfires in a number of different ways. 

Sagging or downed lines from high winds can cause the energy in the line to hit surrounding vegetation and spark a wildfire. That’s what caused the deadly Lahaina fire in Maui in August 2023 that killed more than 100 people.

 

A tree or branch that falls or grows into a line can also cause a fire, which is why utility companies invest heavily in trimming trees and clearing nearby vegetation. As the power line’s electric current completes its circuit, it can heat up the tree. Officials determined the Dixie Fire in Northern California in 2018 started that way.

“The sparks are created because the power is flowing in places it shouldn't be flowing,” said Baker.

 

“It happens a lot. Most of the time it doesn't cause a fire. But that 1% of the time that it does, it's really, really bad,” she said.

Aged wires and transformers can also cause fires, as can worn-out insulation. “You might notice it’s hot in areas it shouldn’t be hot. The power’s flowing in an inefficient way and into places it shouldn’t be,” Baker said.

These issues can be mitigated with routine maintenance, repairs and upgrades. 

Curtis Hartenstine, who manages fire mitigation efforts at Tri-State G&T, said the task at hand is a challenge. The company, which generates and serves power to rural areas across four states including Colorado, has 36,000 structures across 200,000 square miles.

 

“With all these structures, all these distances, and the level of sensory equipment out there for our level of distribution, we're doing what we can, which I think is a great deal, but it doesn't allow us the precision that we'd always like.”

One of the most critical new technologies some utility companies are deploying to prevent a catastrophic wildfire is called enhanced powerline safety settings or EPSS, which Pacific Gas & Electric (PG&E) piloted in 2021 in California.

Xcel Energy announced it plans to activate these settings along the Front Range this week. 

 

If something comes into contact with a power line, the system automatically turns off power and de-energizes within one-tenth of a second. When this happens, electricity doesn’t return to consumers until the utility company is done investigating the fault.

 

Xcel Energy began deploying EPSS in March of 2024 after a California utility advised them to prioritize the technology, said Sherwood.

 

The company says it places powerlines into the EPSS sensitive setting when certain extreme weather conditions are forecast.

 

Xcel Energy has also invested in drones to identify defects in its equipment; artificial intelligence cameras to detect wildfires; underground utility lines in certain high-risk areas; and regular vegetation management to ensure brush is cleared away from their structures.

 

These technologies are costly and require significant resources and manpower, so the company prioritizes the most at-risk communities first.

 

Hartenstine said Tristate G&T utilizes immense amounts of data to assess risk and prioritize where to perform repairs and maintenance.

“We’re as data driven as we can be,” he said. “If we have the data, then we can act on it.”