BISMARCK — The U.S. Air Force is asking North Dakota regulators to consider requiring the buffer zone between wind turbines and intercontinental ballistic missile facilities to increase tenfold.
Representatives from the 20th Air Force, which oversees the 91st Missile Wing at Minot Air Force Base, say their concerns stem from the risk the turbines pose to helicopters flying over missile fields. The missile wing operates the 150 ICBM launch sites and 15 missile alert facilities in North Dakota.
“As the windmills get bigger and there’s more of them, it’s starting to become an issue for flight safety,” Col. Todd Sauls told the Public Service Commission at a hearing on Thursday, Sept. 19.
Lt. Col. Mike Toomer said helicopters are relatively slow moving and would have to do a lot of maneuvering to avoid groundfire if they were ever to come under attack. Air Force helicopters complete about 1,300 missions per year related to missile operations in North Dakota.
“Having wind turbines within their operational space significantly impacts their ability to operate safely under high stress,” Toomer said.
Currently, a wind turbine must be at least 1,200 feet from an ICBM facility. The Air Force representatives asked that the PSC increase the setback requirement to 2 nautical miles, which is equal to 12,152 feet. Such a change would apply only to new wind farms, and it would not affect existing turbines.
The request came during one of several PSC hearings held Thursday for proposed rule changes that would affect renewable energy. The setback change was not included among the proposals the commission was considering, but it’s something commissioners indicated they might pursue down the road.
“A 2-mile setback is pretty sizeable, and I would assume that industry would at least want to know that that’s forthcoming,” Commissioner Julie Fedorchak said. “It seems that there should be notice given to them to provide comments.”
The commission is weighing another rule related to wind turbines near ICBM sites. The proposed regulation would require that wind farms maintain a 30-foot buffer zone on either side of the line of sight between ICBM launch sites and launch control facilities. The wind farm as a whole could span the line between the facilities, but individual turbines would need to comply.
Sauls said turbines placed within the direct line between missile facilities can interfere with data transmission.
A representative from a renewable energy developer said he had no concerns about the 30-foot buffer zone but encouraged the commission to allow the industry to weigh in on any proposal to increase the setback requirement.
Chris Kunkle, government and regulatory affairs manager for Apex Clean Energy, testified that his company is aware of the need to consider military operations and has worked effectively with the U.S. Department of Defense on locating projects.
“This has become a very high priority issue around the country near military bases,” he said. “It has become one of the very first things we look at when we are identifying a project site.”
Kunkle also spoke about another rule change before the PSC, which would reduce the maximum sound allowed alongside homes and businesses near a wind farm.
The PSC is proposing to drop the limit from 50 to 45 decibels within 100 feet of a house or community building, in an effort to prevent the noise from spinning wind farm blades from disturbing neighbors.
Kunkle questioned whether scientific evidence justified lowering the limit, but he said 45 decibels would be viable for his company as it makes plans for wind projects in North Dakota. He said South Dakota regulators have recently approved wind farms with similar noise requirements.
Apex is also considering solar projects in North Dakota and has been eyeing Bowman County as a potential site.
Kunkle encouraged the PSC to rethink part of another rule it’s considering for dismantling solar facilities when they reach the end of their life.
The commission is looking to establish a process similar to its rules for decommissioning wind farms. It would require that companies remove their solar facilities and reclaim the land, as well as put up financial assurance, such as a bond that guarantees money will be available to remove the solar farm one day.
The proposed solar decommissioning rule would apply to all solar farms with a power capacity greater than 500 kilowatts. Kunkle pointed out that the PSC only permits solar farms far greater in size, 50 megawatts or more.
“Although the state does not have permitting authority, it would have decommissioning authority,” he said. “It creates a bit of uncertainty about who’s doing what.”
He said local communities and counties tend to put their own decommissioning rules in place for solar farms in their vicinity.
The Public Service Commission is accepting written public comments on its proposed rule changes through Sept. 30.