Scout Clean Energy spokesperson Mark Wengierski, vice president of development - East Region, joined Scout's marketing director, Will Patterson, and associate project manager Jeremiah Pare at the Carver Center for Public Radio to discuss the status of the Nimbus wind farm.
"Scout was founded in 2016 and we are scouting the frontiers of renewable energy," Wengierski said, first providing a company overview. "So, within our pipeline we've roughly 19 gigawatts worth of projects and that's about half solar, half wind and some battery storage and that's from California to Pennsylvania to many points in between."
Scout Clean Energy is owned by Brookfield Renewable, which operates one of the world’s largest publicly traded renewable power platforms. Brookfield's portfolio consists of hydroelectric, wind, solar and storage facilities in North America, South America, Europe and Asia. Wengierski said Scout has completed five wind energy installations across the country so far, most recently a partnership with GE Renewable Energy to build a 200MW wind project in rural South Dakota.
"We're an owner-operator. So our business model is we develop, we construct, and then we operate the wind farm through the life of the project. So we are a long-term member of the community."
Construction startup for Nimbus will take place after an "offtaker" agrees to buy the generated wind power under a power purchase agreement. Arkansas is among a dozen states with no industrial, commercial or utility-scale wind facilities. Nationwide, the U.S. Office of Energy & Renewable Energy lists Iowa, South Dakota, Kansas, Oklahoma and North Dakota as top land-based wind energy-producing states.
Nimbus has been in development since 2016, but the company only went public early last year after concerned residents caught wind of it and complained to local media. Scout officials responded by hosting several Nimbus "open houses" at a local community center, officially presenting the project.
As many as 48 wind turbines were originally planned. Instead, Wengierski announced that 30 much taller turbines would be erected, including four measuring 590 feet tall and 26 standing 644 feet tall. Due to inflation, the estimated investment cost has also risen over time from $300 million to $400 million, he said. Once built, Nimbus will qualify for federal clean energy investment tax credits that could pay for as much as 30% of that cost.
Scout now has 100% site control, he said, having acquired 53 voluntary land lease agreements across 10,000 acres.
"We are not going to discuss compensation for the landowners, but I will mention that over the life of the project the landowners will receive over $15 million in payments from the wind farm."
Scout has advertised that Nimbus will also generate more than $25 million in property tax revenue over the 30-year life of the project and employ around 200 construction workers. The 53 lease agreements secure land for wind turbine installation, temporary construction materials storage, and private county dirt road expansion to make way for tractor trailers hauling giant turbine tower and blade components, as well as heavy-duty dump trucks hauling tons of foundation materials.
Wengierski said eminent domain declarations— the taking of private property for Nimbus development— won't be necessary due to sufficient easement agreements. The footprint of each of the 30 wind turbines will be around an acre each.
"The remaining acreage, it can continue to be farmed, hunted, it can continue to be grazed, so it's optimal compatible agricultural land use."
But land use is a major sticking point for residents upset about Nimbus. That's because a majority of Carroll County Quorum Court officials claim to have no control over development in the county. Opponents argue that protective land use ordinances drafted back in 1998 and again in 2011 could be updated and enacted to control the commercial development of projects like Nimbus. Nimbus also remains exempt from state oversight by the Arkansas Public Service Commission because it will operate as a wholesale power generation facility, according to a response to a query we made to APSC last year.
More than 2,000 petition signatures have been gathered by opposition groups aiming to block Nimbus, most notably Stop Wind Farms Carroll County AR, which is pressuring the county quorum court to take action. Instead, the county judge this summer announced that a county road use agreement with Scout to expand or reroute dirt roads is imminent.
"So, what that agreement means," Wengierski said, "is you have to have really pristine roads in order to transport your turbine components to the project site. And to ensure Carroll County residents are protected, we're actually going to post a $1 million dollar bond to ensure that the roads are ultimately returned to the same or better condition as how we found them. And there will actually be another account for road maintenance and repair throughout the construction of the project."
Wengierski declined to disclose exact turbine setbacks, which also could be determined by county officials. Setbacks are protective distances between operating wind turbines and adjacent non-leased private property.
"In order to responsibly site our wind turbines," he said, "we've ran through a tremendous amount of science and diligence around modeled noise and flicker levels, and we will not have any exceedances at any occupied residences that would exceed what you see here in the United States."
Generated power from the 30-wind turbine complex will be routed underground to a centralized Scout-owned transformer facility to interconnect to a new four-mile-long Entergy-owned transmission line. The power will then be delivered to an Arkansas Electric Cooperative substation south of Green Forest and placed into a regional grid for wholesale power purchasing.
A March 25th, 2022 document obtained through a Freedom of Information Act request indicates that Scout signed a General Indemnity Agreement with Arkansas Electric Cooperative Corporation and the wholesale Midcontinent Independent System Operator grid, MISO for short, which distributes produced power to 15 U.S. states, including Arkansas, and a Canadian province.
We've previously reported that the Nimbus wind facility location is unique, a Southern proving ground situated on populated Ozark mountain ridges. But Wengierski disagreed.
"This is a viable site, a high-quality wind farm site based off the wind data and the wind turbine technology that will be applied to the project site," he said. "It is not proving ground. It is not a test ground. This is a high-quality wind farm site."
Patrick Gilman is a program manager in the Wind Energy Technologies Office of the U.S. Department of Energy. He educates members of Congress as well as the public on the role of current and future wind energy markets. He said the U.S. currently has around 150 gigawatts of installed wind energy capacity but that wind development in the southeastern U.S. is relatively new.
"We have installed projects in North Carolina, in Tennessee, and one that was recently commissioned in Mississippi," Gilman said. "Ridgetop facilities are actually relatively common in the U.S. and particularly in the eastern United States because that's where the strongest winds tend to be."
Steep mountains force winds to rise, which can be harnessed by wind turbines perched on ridgetops. Gilman also said facilities with tall turbines like Nimbus are currently operating in West Virginia and Pennsylvania. He said nationwide, the average wind tower installed in 2023 was about 560 feet tall from the tower base to the tip of the turbine blade. And near-future wind turbines, he said, will exceed 700 feet.
"Why the wind industry, why utilities are looking at larger turbines is because they can produce energy at a lower cost," he said. "Taller turbines can capture wind that is stronger, higher off the ground, which means that they can generate more energy, and ultimately you need fewer of them to generate the same amount of electricity. And that means you need fewer roads, transport and construction, fewer components, and all of that reduces cost both to the developer but also ultimately to the rate payers."
But Gilman added that building wind turbines on steep mountain ridges poses some real engineering and construction challenges.
"Challenges that you don't encounter when you're building on flat crop land in the Midwest," he said. "For example, it's difficult to get large construction equipment and large wind turbine components to sites, and you might need to use special foundations to deal with rock close to the surface. But those are all challenges that can be addressed with the right engineering and construction practices. And again, we see a number of ridgetop projects that have been operating successfully for many years."
According to US Geological Survey maps, however, much of extreme north Arkansas and southern Missouri is karst terrain, subsurface fractured limestone and dolomite, in some places overlain by sandstone, through which rainfall over eons carved underground sinkholes, caves, springs, and streams. More than 800 springs and 1,240 sinkholes so far have been mapped across the Arkansas Ozarks.
Scout has not publicly released detailed turbine installation site maps for Nimbus, but a late 2023 Nimbus wind project map, obtained by the group Stop Wind Farms AR, reveals turbines are planned along a series of mountain ridges, some reaching 2,000-foot elevations extending from two miles southeast of Green Forest scattered along the length of County Road 905, with more clustered northwest of County Road 920.
Topographical maps of the region, broadly referred to as Bradshaw Mountain, provided for this report by the Office of State Geologist in Little Rock, reveal geologic formations consistent with karst.
Mark Wengierski says multiple geotechnical tests are conducted at every turbine foundation site to determine subsurface stability.
"And those samples are core borings that go approximately 60 feet deep," he said. "So again you've got multiple borings at a single turbine foundation. The individual turbine foundation is only 16 to 17 feet deep. So, we have that data subsurface to ensure there is no karst, there are no voids, there are no subsurface anomalies that could ultimately impact the installation of that turbine."
State geologists declined commenting for this report, but the Missouri Department of Conservation posts an online warning that karst topography can be disturbed by construction occurring miles away.
Residents living within the planned Nimbus construction zone who oppose the project also worry heavy excavation and blasting will impair their springs and wells, which for many in rural Carroll County is their only source of potable water.
But Wengierski said Scout conducts thorough hydrology studies to protect local water supplies.
"A hydrology study is ultimately documenting the water patterns throughout the project site," he said. "So we avoid placement of wind facilities where there is water."
Scout must also obtain Arkansas Department of Environmental Quality stormwater pollution permits prior to construction.
We followed up on the foundation blasting question with Scout's marketing director Will Patterson, specifically asking about the use of explosives. He emailed only that turbine foundation excavation best practices will be used and that multiple regional contractors will supply foundation concrete raw materials, including cement, gravel, sand,= and water.
Finally, we asked Wengierski to specifically comment about the hundreds of families, retirees, local business owners, farmers and ranchers living in the shadow of Nimbus, who are not leaseholders, who will have to deal with impacts from heavy construction, traffic and dust, nuisance turbine operations, and potential private property devaluation.
"Well, first off," he said, pausing for a moment, "we have 53 landowners that have signed voluntary agreements. These individuals are local, they live within the project, they live adjacent to the project, they own the 10,000 acres on which the project will be sited. So we have incredible support from our participating land owners and they're the reason why the project will end up being constructed."
Documents obtained by concerned citizens through Freedom of Information Act requests reveal that Scout agents have been meeting for years with federal and state wildlife officials to draft natural habitat protection plans. Opponents say Nimbus turbines will pose a threat to endangered and listed bats that roost in Carroll County forests and hibernate in karst caves, as well as migrating birds and endangered raptors that could be harmed by giant spinning rotor blades.
We queried Jennifer Koches, U.S. Fish and Wildlife Service Supervisory Public Affairs Specialist in the Office of Communications for the Southeast Region, in late August. Koches responded by email that the agency expects Scout Clean Energy to submit a final draft of the Habitat Conservation Plan soon.
When filed, the agency will publish a notice in the Federal Register requesting a review of the draft Habitat Conservation Plan and Environmental Assessment, opening a 60-day public comment period, possibly this fall. A public information meeting will also be announced.
Finally, Mark Wengierski declined to comment on the status of a Nimbus power purchase applicant during our interview, which will trigger construction start-up. But in a follow-up email Will Patterson wrote that the company anticipates making an announcement in the coming months.
Ozarks at Large transcripts are created on a deadline. This text may not be in its final form and may be updated or revised in the future. The authoritative record of KUAF programming is the audio record.
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