Government Review Process for Radar Interference

Early coordination with the Federal Aviation Administration (FAA), National Oceanic and Atmospheric Administration (NOAA), Department of Homeland Security (DHS), and U.S. Department of Defense (DOD) during the siting process can help prevent a radar interference issue long before a wind plant is built.

The FAA regulates structures 200 feet above ground level, such as utility-scale wind turbines, to ensure that they are compatible with aviation safety and other uses of airspace such as radar. Developers must submit an application through the FAA’s Obstruction Evaluation/Airport Airspace Analysis process, which identifies the potential of radar interference from a proposed wind plant. As part of that evaluation, the FAA notifies other federal agencies with radar assets near the proposed project (such as DOD, DHS, and NOAA) so they can determine the potential impact. The DOD Military Aviation and Installation Assurance Siting Clearinghouse (also known as the DOD Siting Clearinghouse consolidates the inputs of DOD branches, offices, and bases that conduct analyses to assess potential impacts on their missions.

The DOD Siting Clearinghouse has a structured formal review process to conduct a mission compatibility evaluation of proposed wind projects submitted to the FAA. The DOD Siting Clearinghouse established an informal review process and encourages all developers to request a preliminary determination prior to submitting an application with the FAA. The informal review process provides a timely, transparent, and science-based analysis of potential project impacts, alerting project developers and federal agencies to concerns before entering the formal FAA review process. If concerns are identified, the Siting Clearinghouse works with industry to mitigate the issues, if possible, overcoming risks to national security while promoting compatible domestic energy development.

NOAA also has an early review process separate from the FAA process. NOAA provides a description of the process on its Radar Operations Center website.

Online tools are available to assist wind developers with preliminary site screenings before engaging with federal agencies: the DOD Preliminary Screening Tool, the NOAA NEXRAD Screening Tool (which includes the U.S. Wind Turbine Database), and the DOD Siting Clearinghouse.

Mandatory Formal Review

Once a project is officially submitted, the FAA Obstruction Evaluation/Airport Airspace Analysis process identifies the potential of radar interference from a proposed wind plant and disseminates proposals for interagency review. The FAA requires developers to file notice 90 to 120 days before planned construction. To enable evaluation of potential impacts on national airspace, proposals must include individual turbine configurations (including latitude/longitude and turbine total height) as well as the project layout at the time of filing.

Entering a wind project into FAA’s mandatory obstruction evaluation review process triggers additional assessments by DOD and DHS for mission compatibility. If a project is determined to have a potential adverse impact to, for example, DOD military readiness (research, development, test and evaluation, training, and military operations) or DHS interests, the agencies collaborate with wind plant developers to determine mitigation options. The DOD Siting Clearinghouse has evaluated approximately 10,000 energy projects since 2010 to determine potential impacts on military operations, with only one instance in which differences could not be resolved.

For more information, see frequently asked questions on DOD’s informal review and formal review processes.