In a letter to Texas Sen. John Cornyn, the Department of the Navy said a study it commissioned has found that student pilot training operations could be hindered by wind turbine technology.
Cornyn has filed legislation in the U.S. Senate that would prohibit wind developers from receiving incentives through the Renewable Energy Production Tax Credit as well as the Investment Tax Credit should they build wind farms within a 30-mile radars of military airfields. The senator sent his concerns to the Navy, specifically pointing out potential conflicts in South Texas as it relates to Navy pilot training programs.
Cornyn wrote in his March 27 letter that South Texas Wind Farm Cumulative Impact Analysis, the Navy-funded study, at Naval Air Station Kingsville and Naval Air Station Corpus Christi looked at wind turbines that were taller than 500-feet. He said since federal tax incentive programs were created for wind farm developments, more of the energy-producing farms have been constructed, affecting military flight operations.
"With a growing number of wind turbine farms surrounding bases like NAS Corpus Christi and NAS Kingsville in Texas, I am concerned that we are just beginning to see the leading edge of the negative impacts that continued encroachment will have on safety and training," the senator wrote. "Unfortunately, the SPAWAR Report did not address wind turbine farms as obstructions to navigation or impact on military readiness.
The letter to Cornyn, which is dated May 31, indicates the department is also concerned about safety and operational readiness when it comes to their student pilots. The Navy says wind developments in South Texas have "incrementally impacted" flying training, but they've been able to mitigate the effects of the turbines and have "avoided impacts to student progression."
"Maintaining the ability to train Naval Aviators (sic) requires a safe operating environment with adequate airspace ... and supporting infrastructure such as outlying landing fields and weapons ranges," said Deputy Assistant Secretary of the Navy James Balocki. "Continued development may eventually overcome our ability to operationally adapt or consider feasible and affordable mitigation actions."
When able to, the Navy and developers have worked to lessen the impact of wind farms on pilot training, usually with the developer picking up the cost.
Ongoing efforts include improving air traffic control coverage, Balocki wrote, as well as working with the Federal Aviation Administration on creating new rules for air space near wind developments.
Despite those efforts, the Navy said the study showed wind farms do and will affect the airspace around them.
"The general conclusion of the study confirmed that primary radar detection may be significantly degraded in airspace immediately above wind farms and in some cases in areas beyond the windfarm (sic)," Balocki wrote. "When flying in such areas of degraded primary radar coverage, there is increased risk to Navy pilots from civilian aircraft operating without active transponders."
The Navy also claims wind turbines also cause a physical threat to aviators because of their height, specifically saying that structures 500-feet-tall would affect low-level flight requirements.
"As a result, low-altitude flight training must be completed in a decreasing amount of airspace designated for military training operations that remains unencumbered. Attempting to replace low-altitude trainng areas lost to obstruction would require the FAA to approve new airspace designations; this is a lengthy, expensive and potentially controversial review process with no assurance that such airspace would remain free from encroachment."
Jimmy Horn, of Horn Energy LLC, which has had plans to development wind farms in Byers and Blugrove, said in a February Times Record News article that the courts have determined have determined at what elevation a landowner has rights to above the ground and where navigable airspace begins, which is defined the airspace at and above minimum flight altitudes.
"These 30-mile radius bills seem to contradict the legal actions in the U.S. for landowner rights to use their land up to 500 feet AGL (above ground level) ... and may open the door to the military losing their rights via new legal actions to fly below 500 feet for their training routes," he said. "Slippery slope."
Balocki said the Navy will continue to look at the effects of turbine technology on radar equipment, as well as airspace in which student pilots will fly. If mitigation efforts cannot be agreed to, the department will ask the secretary of defense to object to the development.