Wind Turbines vs. Weather Radar in Tornado Alley (Nebraska showdown)
By Lisa Linowes -- August 11, 2015“What about the more than 50% of Nebraska’s severe weather that occurs at night and with no regard for holidays and weekends? Does anyone expect NextEra employees to make up for the loss in radar resolution from the company’s wind power facilities?”
Since 2009, two Nebraska communities have been destroyed by tornadoes, the most recent in June, 2014 (in Pilger). Articles covering these disasters can be found here and here.
Needless to say, accurate weather forecasting is essential for protecting life and property. But what happens when wind turbines are placed too close to a NEXRAD [1] weather radar? We may know soon enough.
NextERA’s Cottonwood wind project (113.6 MW) proposes to site all of its 52 turbines within 2½ to 7 miles of the Blue Hill, Nebraska NEXRAD facility. This will be the closest of any operating turbines in the U.S. to weather stations in Tornado Alley.
Privately, local weather service employees have expressed concern and, given Nebraska’s storm history, they’re right to be wary. An illustration of the project and radar station can be viewed here.
Weather Radar and Turbine Impact
Forecasters watching for severe weather look for key indicators in the radar data including the strength of the signal reflecting off the storm cloud, the rate at which the cloud is growing (or if its decaying), and its direction/speed. This information is critical in determining the size and intensity of the storm and the geographic area likely to be impacted should a warning be issued.
Wind turbines within 30 nautical miles of weather radar (line of sight) can significantly compromise the radar data [2] and impair a forecaster’s ability to evaluate developing weather events. Tracking a storm’s rapidly changing behavior as it moves into the turbine obstructed radar beam (the “cone”) is complex and may not be possible.
Washington Knows Better
But not to worry. According to NOAA’s Administrator, Dr. Kathryn Sullivan, concerns about NextEra’s project are misplaced. In a letter to Nebraska Senator Deb Fischer, Dr. Sullivan touts an agreement signed between the Hastings, NE Weather Forecast Office (WFO) and NextEra [3] outlining mitigation steps for curtailing project operations during severe weather conditions. Shutting down the turbines will enable weather forecasters to view radar data that’s uncontaminated by the moving blades.
“[T]he mitigation strategy and forecaster training,” wrote Dr. Sullivan, “will reduce impacts and ensure that the Cottonwood project is not a threat to the integrity of NOAA’s forecast and warning operations.”
Convinced? Don’t be! For starters, the agreement is entirely voluntary and non-binding on the parties. But there’s more.
Mitigation Plan Ignores Reality
The NextEra-WFO agreement provides a sample scenario of the curtailment process as shown in the table below:
| 3:20pm | WFO forecaster identifies severe thunderstorm with tornadic potential 15-miles SW of the wind farm and on track to pass over or near the project at approximately 4:14pm; |
| 3:21pm | Forecaster asks the Severe Weather Coordinator to contact the wind farm and request operational curtailment beginning at 4:00pm and lasting 30 minutes; |
| 3:26pm | Severe Weather Coordinator contacts wind farm and makes request for curtailment; Wind farm agrees to curtailment and initiates shutdown; |
| 3:56pm | Turbine shutdown complete; Forecaster interrogates storm; |
| 4:20pm | Forecaster issues tornado warning; |
| 4:25pm | Storm clears the wind farm; |
| 4:30pm | Wind farm resumes turbine operations; |
| 4:40pm | Wind farm back to full operation. |
It would be nice if the growth and decay of severe weather were that well known, but it’s not.
For forecasters watching a developing thunderstorm, the total time interval during which the storm might cause damage is very short, but critical, and very difficult to forecast even with full radar access. Severe weather events can form, explode into massive life-threatening storms and fully dissipate all in under an hour, making the timeline depicted in the above table utterly laughable. In the real world, the storm threat may be over before the turbine shutdown is complete.
The area near the Cottonwood project, on average, experiences roughly 48 thunderstorm days per year (as many as 50-60+ storms) during the spring and summer months. Statewide over 11,000 hail events can be expected in the same period. [4] Are all of these events severe enough to trigger warnings? No. Can any one of these evolve into a severe storm? Yes!
A line of storms approaching at the right angle could fall within the obstructed area of the radar beam for many, many hours. Ideally, curtailment requests should be in effect for as long as the storm threat exists, but that’s not what the agreement says. The maximum duration of any shutdown is 1-hour with no more than 12-hours of curtailment enforced per year. NextEra is assured 15-30 minutes lead time for shutdowns during regular business hours. Longer time is needed on holidays, evenings, and weekends. After all, everyone knows weather slows down with the rest of us.
Why would any experienced meteorologist agree to force-fitting severe weather forecasts into NextEra’s tidy schedule? Maybe because NextEra promised to help out.
According to Dr. Sullivan, the project’s full-time wind farm operators will be trained as storm spotters.
Seriously?
What would they be trained to spot, a thunderstorm? By time they see the storm it’s too late. If they spot a tornado, it’s really too late. What about the more than 50% of Nebraska’s severe weather that occurs at night and with no regard for holidays and weekends? Does anyone expect NextEra employees to make up for the loss in radar resolution caused by the company’s wind power facilities?
More Window-Dressing By Big Wind
Accepting these mitigation measures without fully understanding their effectiveness could place the lives and property of Nebraskans at risk. And what happens if/when the WFO finds its forecasting work is compromised by the project?
Paragraph 15 says they can have a sit-down with NextEra. Paragraph 16 prohibits the parties from publicly commenting on the performance of the other so if the mitigation fails, we’ll never know. Then there’s Paragraph 19 which says the agreement terminates after 5 years but either party can end it at any time.
This agreement is nothing more than window-dressing. If Dr. Sullivan read it, and that’s a big ‘if’, the people of Nebraska could not have been her first priority when she responded to Senator Fischer.
Hopefully, Senator Fischer and newly elected Senator Sasse are paying attention to what’s happening in their state. For those living outside of Nebraska, we should be keenly aware of how the wind industry has been allowed to degrade our public assets and place our fellow Americans at risk.
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[1] Next Generation Weather Radar (NEXRAD) system. NEXRAD is a key tool used by weather forecasters when preparing forecasts and severe weather warnings.
[2] Turbines impact radar data in at least two ways: (a) the spinning blades can block a significant percentage of the radar beam and decrease its signal strength down range of the wind facility; and (b) the turbines reflect energy back to the radar system which can produce false storm activity. NEXRAD filters that remove clutter from the radar signal only work for stationary objects (buildings, trees and terrain).
[3] In the agreement, NextEra is operating as Cottonwood Wind Farm, LLC.
[4] Data supplied by the Warning Coordination Meteorologist at the Storm Prediction Center in Norman, Oklahoma.
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Author Lisa Linowes wishes to thank meteorologist Dr. Fred Ward of Boston who helped her better understand the difficulties of forecasting weather and the importance of radar.
They don’t need to wait to see what the effects will be. All they have to do is look at western New York State’s weather radar. With 308 industrial wind turbines strewn throughout five towns in western Wyoming County, Doppler radar can no longer accurately predict the weather here. It looks like there is a constant storm going on here.
After Invenergy’s 58-turbine Orangeville, NY project went in in 2013 (after the Wind PTC was added as pork to the Fiscal Cliff Deal), Wyoming County’s Emergency Communications tower would no longer work. Senator Chuck Schumer was just in the area yesterday bloviating about getting a new permit for a new tower.
Most comical, as cited in this Buffalo News article (see link below), is the fact that they are waiting for the FAA’s “no hazard” determination for the new 500 foot-tower. Ironically, in the immediate vicinity are 308 industrial wind turbines, many of them nearly 500 feet tall, with 11-TON blades spinning at nearly 200 mph which can, and have, blown apart. Yet, the wind turbines didn’t have any problem getting the “no hazard” determination from the FAA. What a joke.
WHY is it that taxpayers will now be on the hook for paying for this tower when it was Invenergy’s Orangeville wind factory who rendered the original tower useless???
BUFFALO NEWS: Schumer Pushing for New Wyoming County 911 Radio Frequency Channel:
http://www.buffalonews.com/city-region/schumer-pushing-for-new-wyoming-county-911-radio-frequency-channel-20150810
I really love your allegations about how unpredictable weather is, because it is.
But I hate to break it to you, but if the forecast shows it exactly the way it is or not, the same storm is STILL GOING TO OCCUR. Yes, tornadoes are awful and towns get destroyed, but if a storm is capable of a tornado, every weather channel will be warning us way before it is 2 miles out of Blue Hill.
The tornado in Pilgar was terrible, but I guarantee you, if there was 1000 wind turbines right beside Pilgar, that tornado would have still happened, and the effects would have been the same. I actually was in attendance at a meeting where NOAA employees talked with fellow Blue Hill citizens about the effect of the wind turbines on the weather forecast, and I very closely remember them staying they will be able to update software and ADAPT to the changes they will see.
This whole thing is getting blown way out of proportion. Nearly everyone is forgetting the main reason behind erecting wind turbines. It’s not to aggravate people; it’s to reduce our use of fossil fuels. Has anyone been talking about the harmful effects of burning coal? Would people rather have a coal plant in their backyard? I think not!
We all need to get past our unwillingness to change and move on. We deal with many other problems, and this inconvenience does not need all this criticism and time.
Jace,
I am so glad to see young people interested in studying evolving energy prospects. However, in answer to your question regarding living near a coal plant….we have adult children and family living very near a coal plant. At this time and with the information I have studied and the real-life experience of having someone that is living close to a coal plant, my answer would be, “Yes”, I would choose the coal plant. This choice is not just based on the proximity to a weather station, but rather it is based on wildlife habitat destruction, noise pollution, changing view-sheds for many, and health risks that are documented but not widely circulated and known. Just wanted to share my opinion.
Jace, thanks for your comment. And yes, the tornado is “still going to occur”. But the forecaster won’t necessarily know whether it is or not. “every weather channel” depends on the same data, from the same obstructed radar. They have no telephone to the weather master in the sky. If the National Weather Service can come up with a way to “adapt”, fine. But if they had a way now, why do they need an agreement?
Great article.
Not only is wind energy wildly inefficient, they will do almost anything to get their taxpayer money. There is absolutely no regard for people or risks when they site a wind facility. In regards to the article, the issues created with siting a wind complex this close to radar is just one issue of many (decreasing property values, noise, shadow flicker, ice throw, inefficiency, dependence on tax payer money, etc). Just because something is labeled as “green” or “renewable” doesn’t mean it should get a free pass or not be put under the microscope. I can put a label of “candy” on a piece of crap, that doesn’t mean it is or that people should believe it.
But the main issue within this article is simply that wind energy will never be an all encompassing means of good, reliable energy. When these turbines shut down because of a storm (if they actually even would), it puts more strain on the overall energy grid. The up and downs with wind speed already put a strain on the grid and shutting them down would add even more. So what does that do to other plants, such as coal, nuclear, solar? It makes them ramp up and down and more inefficient and what does that do to energy as a whole? Makes it more expensive to create! Come on people, start using your common sense. It’s time to kill the weak and make the strong, stronger and better. The whopping 4% of US energy wind creates is driving up prices already…what happens if they continue to expand?
But yes, we are living in a time of drinking the “green” kool-aid. If Nebraska really wants to be a wind State, we need to do it right. That means properly siting these away from homes, schools, communities, major roadways, radar, etc. We also need to force wind developers to stand on their own two feet. This will help them to become less expensive for rate payers. We need to do our due diligence and research this means of energy more before we make a mistake we must live with for 30+ years. Take a tour of our neighbor, Iowa, what are their issues or advice? Iowa’s energy prices have increased at one of the highest percentages in the US! Coincidence? More research and thought needs done. No one wants to pollute our world more, but we shouldn’t have a knee jerk reaction to cyclical changes in climate….which is where this all stems from ($$).
In closing, severe weather doesn’t care if there is a turbine in its path or not. But do we really want to go backwards in our attempts to use our radar technology to its absolute fullest? I don’t want our local meteorologists to have to “adapt” to clutter on radar…I want their skills and technology to get even better…give them every opportunity and tool to succeed in the future. Your home or life may depend on it.
http://www.forbes.com/sites/jamestaylor/2014/10/17/electricity-prices-soaring-in-top-10-wind-power-states/
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