A retired meteorologist was in Cameron, Missouri recently for a discussion with those concerned about wind turbine development in the area.
Mike Thompson, former chief meteorologist for WDAF-TV in Kansas City, gave a March 21 presentation attended by more than 250 people from across the region. They were on hand to discuss the proposed extension of the DeKalb County wind farm into Buchanan County by NextEra Energy.
Thompson said he began researching the building of the 500-foot wind towers in the Midwest after learning that wind speeds must be around 10 miles per hour for a wind turbine to produce measurable energy.
He said a turbine does not produce its standard rated amount of 2-megawatts of electricity until the wind is sustained around 25 miles per hour or greater due to the size and weight of the blades. A wind turbine will turn off when winds reach roughly 55 miles per hour to prevent equipment damage.
Thompson said his research has shown that during the last three years there was one day in St. Joseph that had an average daily wind speed of 25 miles per hour and that was in March of 2017. There were around 30 days of wind per year that reached around 15 miles per hour, which produces slightly less than half of their rated capacity, he said.
“Many times when the wind blows, it is not at the most beneficial time of day or time of year,” Thompson said. “You will sometimes have wind at night when there is a lower electrical demand. It is also possible at times that the blades may be turning but producing a relatively small amount of electricity.”
Thompson said the development of large wind farms also can have an impact on the use of weather radar.
“There can be localized effects to weather radar after the turbines are built,” Thompson said. “The National Weather Service has documented that turbines can create false echoes on Doppler radar.”
Some residents near wind farms also have reported that ice can be thrown from the turbines during winter if the weather conditions result in the rotor blades collecting ice. Thompson said research conducted by the wind company Apex estimates there can be up to 50,000 particles of ice thrown a year and some can reach a maximum distance of 3,200 feet.
In addition, there have been reports across the country of the turbines creating noise due to the air compaction when the blades go past the tower and there are studies being done on the impacts of low-frequency infrasound.
He said other nuisance reports from landowners have included turbine lights flashing in unison at night.
Thompson said easement restrictions can be placed on farms depending on the individual lease and property size.
“There is a safety zone around the circumference of the turbines that is put into the lease,” Thompson said. “This is usually 500 feet but that can vary by company. Then there are easements outside of that lease pertaining to access roads and the ability for equipment to enter the property for maintenance.”
The presentation on wind energy was sponsored by the Concerned Citizens of Clinton and DeKalb Counties, which serve as educational groups on wind tower development. For more information on those organizations, contact Bruce Burdick at 816-803-4669 or by email at firstname.lastname@example.org.
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