Weather experts confirm turbine impact on Doppler 

PRINCETON – Weather experts last week confirmed to local officials some of the same concerns voiced in July to Gibson County Commissioners about a proposed wind farm’s potential impact on the Doppler radar tower in Gibson County.

Notes were made available to Gibson County Commissioners and others from a private fact-finding meeting Aug. 20 with National Weather Service and National Oceanic and Atmospheric Administration experts and Gibson and Posey County officials.

The meeting came after a Poseyville woman first spoke with NOAA/NWS officials, then reported the potential for radar interference, to Gibson County Commissioners.

Radar program manager Jessica Schultz of NOAA/NWS, NWS meteorologists James Alton and Rick Shanklin and other NWS experts reiterated that wind turbines constructed within an 11-mile radius of the radar tower near Owensville could degrade the radar capability. Schultz reported that NWS highly discourages developers from building anything within 2 1/2 miles of the radar tower

Schultz said NOAA/NWS talks to developers about potentially lowering height of proposed wind turbines to reduce the impact on radar systems, but the terrain plays a role. “With this particular project, since we have not received project information from the developer, we cannot speak of any specifics,” she confirmed.

She told local officials that when a developer submits the project for analysis, NOAA/NWS provides maps and information about how far away turbines would need to be located to have low to minimal impact on the radar. “Part of our analysis process is, we tell developers what kind of impact we’re expecting and where they can locate the turbines of least impact as possible.”

Schultz said NOAA/NWS has reviewed more than 200 projects across the nation involving wind turbines 590 feet or taller in the past 12 months, but has not been asked yet to conduct such an analysis for Gibson or Posey counties.

She said developers can enter a legally binding “curtail agreement” with NWS promising to shut down turbines in the event of severe weather in the area, which can help reduce concerns about radar data integrity.

But, she said, NOAA has no legal recourse if a wind farm interferes with Doppler signals.

She said NOAA recommends that developers lower turbine height, place turbines farther away from radar, encourages developers to line turbines up as much as possible to minimize contamination of the radar data, but those recommendations are not binding.

The curtail agreement is legally binding, she said, but NOAA/NWS “have yet to find a developer willing to sign an agreement.”

During the meeting, Gibson County County Attorney Jim McDonald asked whether NOAA/NW could review a curtail agreement if the county entered such an agreement with the developer.

Schultz said the curtail agreements are between NOAA and developers, not the county.

In July, Sarah Newton of Poseyville told Gibson County Commissioners she is concerned about the proposed wind farm’s impact on the Doppler radar, noting that neither the National Weather Service nor NOAA has the authority to stop a wind project.

She said enacting a zoning ordinance is the only way to protect the integrity of the Doppler radar’s ability to monitor low-level weather.

In that meeting, commissioner Steve Bottoms told Newton that with no zoning, the county cannot regulate land use.

The GibCoWind group encouraged commissioners to revive the county’s exploration of land use planning/zoning, which was dropped in early 2018.

In March, E.ON Climate & Renewables representatives reported in a public meeting that the company plans a wind farm in Posey and southern Gibson County – and is exploring the feasibility of a second wind farm in areas northwest and south-southwest of Princeton as well.

Wind Development Manager Karsen Rumpf told commissioners at that meeting that E.ON has been involved in land acquisition for 13 months in Gibson County as part of a three-part study of developing a Gibson County wind farm. He said more meteorological and environmental studies and permitting processes are ahead over the next two to three years, before a wind farm layout is finalized.

E.ON representatives said in March the company is either completing or negotiating lease agreements for about 9,500 to 10,000 acres, and would like to have agreements for about 2,000 to 3,000 more acres.

The process involves working with U.S. Fish and Wildlife, Indiana Department of Natural Resources and Indiana Department of Environmental Management, the Federal Aviation Administration for proper permitting, as well as working with the county regarding floodplain permits and use of county roads.

Efforts to get comment from E.ON representatives regarding some off the issues discussed in last week’s fact-finding session were not successful Tuesday.

But in March, when Jim Tate of rural Princeton asked whether the turbines would interfere with the county’s Doppler radar system, Rumpf said the federal government requires turbines to be located no closer than three nautical miles from a Doppler tower. “It’s part of our due diligence,” he told Tate.