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Wind farms aren’t all ready for icing amid changing climate

Bitter cold and icy conditions in Texas showed that wind farms are built for yesterday’s climate and often not winterized to withstand changing weather due to climate change.

Wind farm operators install de-icing systems only if they make economic sense for the climate they’re in—not necessarily to avoid icing in a freak Arctic blast, renewable energy experts say.

One of the biggest challenges facing wind farm developers is climate change, which scientists say is causing the Arctic to warm, possibly disrupting the jet stream so that frigid polar air dives south more often.

“We’re not building power plants for tomorrow’s weather,” said Michael Webber, a mechanical engineering and energy resources professor at the University of Texas-Austin and chief science officer for Paris-based ENGIE SA. “We need to recognize that weather will change based on these trends.”

Although some Republicans have sought to pin the blame on wind turbines, energy experts note that the state largely relies on natural gas, the infrastructure of which was unprepared for the plunging temperatures brought by the storm.

Like those plants, wind farms also suffer from a lack of standards related to weather conditions, and de-icing solutions can be expensive and energy intensive.

Built for Winter?

Wind turbines generate electricity in the harshest conditions—from Antarctica to the North Sea, but each wind farm is built for the climate conditions in which it is expected to operate, Webber said.

Electric reliability standards are in place for utilities, but they don’t specify what kind of wind turbine should be built for a given climate, and some operators will invest more in reliability than others, he said.

“You have to make a choice about what investments to make—to winterize it or not,” Webber said. “The answer in Canada will be different than in West Texas.”

Texas Gov. Greg Abbott (R) on Thursday demanded that state lawmakers make winterization mandatory for all power generation stations in Texas.

None of the three major West Texas wind farm operators responded to requests for comment this week, including RWE Americas, NextEra Energy and Invenergy.

Kimberly Mielcarek, spokeswoman for the North American Electric Reliability Corp., which sets electric grid reliability standards, said there are no winterization standards for wind farms and declined to respond to specific questions.

Mielcarek pointed to a webinar NERC officials prepared in September outlining proposed electric reliability guidelines for utilities to use this winter suggesting that variability in wind power production is making utilities’ electric power generation forecasts less reliable during winter.

But Alison Silverstein, an Austin-based independent energy consultant warned that “guidelines are not mandatory” and that industry standards aren’t broad enough.

Sam Brock, spokesman for the American Clean Power Association, which represents wind power producers, said developers carefully consider what de-icing technology to install on their turbines according to the local climate.

De-Icers Costly

And wind farm developers do have a range of winterization options for their turbines. What they choose comes down to what’s most cost-effective, said Paul Veers, chief engineer of the National Renewable Energy Laboratory’s National Wind Technology Center in Colorado.

Builders have to consider cold temperatures, humidity, and expected level of icing their turbines might encounter, Veers said.

“It is an economic issue about how much you pay for different kinds of systems that help your resistance” to winter conditions, Veers said. “You can gold-plate things, but is that really the right answer?”

Scientists are working on technology that will make wind turbine de-icing systems more efficient.

Ice changes the geometry of wind turbine blades, reducing the ability of a turbine to spin and generate electricity, said Hui Hu, an aerospace engineering professor at Iowa State University who is researching more efficient anti-icing technology.

Anti-icing systems take several different forms, including ice-resistant coatings applied to turbine blades and heaters, he said.

But blade heating systems sap energy, costing up to 70% of the electricity the turbine generates—a cost most wind farm operators find unacceptable, Hu said.

‘Ozzie and Harriet’ Weather

Shoring up the wind farms and the rest of the power grid to withstand extreme weather events will involve devising and implementing weatherization requirements for all types of power plants—including wind—for both summer and winter on a mass scale, Silverstein said.

In addition, she said, electric utilities and grid operators will need to anticipate a changing climate.

“We built this grid for ‘Ozzie and Harriet’ weather,” but the Electric Reliability Council of Texas, the state’s grid operator, doesn’t account for climate change in its planning, Silverstein said.

ERCOT didn’t immediately respond to a request for comment Thursday.