Why the Growth of Wind Energy Worries Weather Forecasters in Oklahoma

Radar systems engineer Redmond Kelley and Caleb Fulton, an assistant professor of engineering, test an experimental phased-array weather radar in Norman.

Radar systems engineer Redmond Kelley and Caleb Fulton, an assistant professor of engineering, test an experimental phased-array weather radar in Norman.

Oklahoma is now No. 6 in the nation in wind-generated electricity capacity, and last week the state helped set a wind power record for the entire region.

Wind farms are multiplying and expanding in Oklahoma, Texas, Kansas, and throughout the Great Plains, where the nation’s wind energy potential is concentrated.

The industry’s growth is worrying weather forecasters because wind turbines can confuse radar.

The problem is the 150 foot-long blades spinning atop a wind turbine and the undulating, ominous clouds that accompany severe weather look the same to the computers that digest and display weather radar data, says Ed Ciardi, a meteorologist for the National Oceanic and Atmospheric Administration.

Ciardi, who works at NOAA’s Radar Operations Center in Norman, which controls all 160 of the country’s NEXRAD weather radar sites, pulls up a feed from a station near Frederick, Okla., in southwest Oklahoma. The screen shows a line of storms to the east, and what appears to be a storm cell to the west, just south of the Red River.

A NEXRAD weather station near Frederick, Okla., interprets a wind farm near Vernon, Texas, as a storm cell.

Weatherunderground

A NEXRAD weather station near Frederick, Okla., interprets a wind farm near Vernon, Texas, as a storm cell.

“They look like thunderstorms or strong rain showers,” Ciardi says, looking at his feed from the radar station.

The storm cell 12 miles north of Vernon, Texas is a ghost. It’s actually the Blue Summit Wind Energy Center, a wind farm that started operating in 2012.

This is not a new phenomenon; meteorologists and scientists have known about wind turbine interference for years. U.S. Department of Defense raised the issue in 2006 over concerns that wind projects might impair military radar.

“A weather radar works by sending out a pulse of radio energy. It bounces off raindrops, hailstones and so-forth, comes back and tells us something about the target and the speed,” says Robert Palmer, a professor and associate vice president for research at the University of Oklahoma’s School of Meteorology.

But because turbines are moving with the wind — the same wind that’s powering storms and weather systems — current radar technology can’t tell the difference.

Solving the Problem

There are two solutions to the problem, and both have complications.

One is to write new computer programs to filter out wind farm clutter, which Palmer has been working on for seven years.

Advanced weather tools, like this phased-array radar being tested by engineers with OU's Advanced Radar Research Center, could help solve the wind farm clutter issue, but are likely decades from operation use, meteorologists say.

Joe Wertz / StateImpact Oklahoma

Advanced weather tools, like this phased-array radar being tested by engineers with OU's Advanced Radar Research Center, could help solve the wind farm clutter issue, but are likely decades from operation use, meteorologists say.

“The algorithms we’re coming up with are really complex,” Palmer says. ”There are processors that are capable of doing it, they’re just not on the operational weather radars.”

Installing computers capable of running new filtering algorithms would require upgrading radar stations, a process that would include a lengthy field-testing process — in all, a time-consuming and expensive proposition for a federal agency facing uncertain budgets.

Another solution, says Ciardi with NOAA, is preventing wind farms from being built near weather radar stations. “But the wind resource happens to be right where the most severe weather occurs,” he says.

Wind farms are multiplying and expanding in Oklahoma, Texas, Kansas and throughout the Great Plains, where the nation’s wind energy potential is concentrated. Ciardi doesn’t think it’s going to be possible to keep all the turbines away.

The U.S. and state governments don’t have rules preventing wind operators from building near weather radar stations. NOAA is relying on the wind-energy industry to voluntarily submit new wind projects for the federal agency to review. “It’s been a pretty good working relationship, and so far we’ve had pretty good cooperation,” Ciardi says.

‘Clutter’ Confusion

There is some anecdotal evidence that wind farm radar clutter has impaired weather forecasts in the past, but Ciardi says it’s mostly a nuisance — right now. But more wind farms could mean more confusion.

“And that confusion will cause them probably to play on the safe side and issue more warnings than are necessary,” Ciardi says. “So we’d have increased false warning rate for severe weather.”

Ciardi says false warnings train people to ignore forecasters. And when forecasters cry wolf, Oklahomans may stop paying attention, which can create a real danger in Tornado Alley.


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Comments

  • Stephen Willis

    It is pretty ironic that weather forecasters are so concerned about “wind turbine clutter” that might impact the timeliness of a severe weather warning. Nowhere do they mention the increasing carbon dioxide and other greenhouse gases as the actual cause of the increasingly severe weather patterns. Nowhere do they mention Global Warming, as the source of increasingly deadly storm cells and super tornadoes such as the one that struck Moore, Oklahoma earlier this year. And nowhere do they acknowledged that wind energy is competitive because it is renewable and part of the move away from fossil fuels. It would seem that the larger problem is the failure to report on severe weather in relation to the steady increase of greenhouse gases being pumped into the atmosphere. It’s no longer a secret; and it never was a myth.

    • an actual meteorologist

      As meteorologist we are able to actually understand the difference between a stronger storms vs an increase in population density in areas that at one time were just farm lands.

      More people = more damage
      More people = more sightings

      But you don’t want to hear that because you already have your mind set…

      • http://stateimpact.npr.org/oklahoma Joe Wertz

        Population is a huge component here. Question for an actual meteorologist: It seems like a lot of storm data depends on human reports and sightings. And, obviously, we’re most concerned with storms as a risk to populated areas. But how do you get good data on rural storms when there just aren’t many observers? I would think the margin of error would be really high?

      • Stephen Willis

        This seems reasonable, but is a red herring. My comment has nothing to do with this point. Any claim to be “an actual meteorologist” is impossible to confirm if you only post as a guest, literally with no credentials other than an assertion. Not too impressive, and not worth responding to in general. Can you even say “Global Warming?”

    • another meteorologist

      Not to mention the fact that 2013 is on track to be the year with fewest tornadoes in the past decade, perhaps the fewest since the 50s. But don’t let facts get in the way of your Global Warming dogma. Nobody else does.

      • Stephen Willis

        And here we have “another meteorologist” maybe like the list of speakers at the Koch Brothers / ExxonMobil funded Heartland Institute, busy creating a whole echo chamber of “climate change denialism.” DeSmog Blog does a good job of discrediting the Denialist trolls wherever they spew their propaganda. You are nobody until you produce some proof you are a meteorologist. If you want to be associated with the loony birds of history, let’s see you use your real name and where you forecast the weather. LOL

  • Ted

    You just have to look at higher elevation scans to see if there is anything there. Easy enough for a human to do to confirm a storm (or not), but perhaps a bit more complicated for a computer algorithm. The bigger problem is when there really is a storm over the turbines, and then it’s probably hard or maybe impossible to deconvolve the signals.

  • thesparky1

    Simply cause the computer to ignore data from the fixed cause. Sure a tornado may form there some day. Maybe put in a second detector that senses major movement of the wind generator apparatus. If its is pulled out of the ground, issue a warning.

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