Heather O’HaraPrincipal Research AnalystHeather.O’Hara@klrd.ks.gov785-296-7792
In 2021, Kansas was ranked among the top five states in total wind energy generation, with the third-largest share of electricity generated from wind power, following closely behind Iowa and South Dakota. In early 2022, the state had nearly 8,250 megawatts of installed wind generating capacity.
Wind turbines have certain safety requirements in place to ensure they can be seen at night. One requirement is the installation of red lights on turbine blades, which present as circulating red dots in the horizon.
As the number of wind turbines increase, so do the number of red lights visible in the night sky. New technologies have arisen to mitigate potential lighting concerns, such as Aircraft Detection Lighting Systems (ADLS).
Aircraft Detection Lighting Systems, sometimes referred to as Aviation Detection Lighting Systems, are radar-based systems that prevent wind turbine lights from turning on unless an aircraft is approaching or descending toward a wind facility. With ADLS, the Federal Aviation Administration (FAA) requires lighting to be activated and flashing if an aircraft is at or below 1,000 feet above the tallest wind turbine and is approaching a 3-mile perimeter around the facility.
The FAA has issued guidance to wind developers to ensure aviation and wildlife safety regarding turbine lighting and visibility in its Advisory Circular AC/7460-1M titled, “Obstruction Marking and Lighting” (https://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.current/documentnumber/70_7460-1) dated effective November 16, 2020.
The Circular includes standards for turbine paint for all turbines and light color and strobe specifications for turbines at or greater than 500 feet above ground level. All vendors offering light mitigating technologies must be certified by the FAA, and every project requesting such technology must submit a request to the FAA, which evaluates each request on a turbine-by-turbine basis.
The FAA may deny the request based on factors such as proximity to military training areas, airports, or low-altitude flight routes.
As of October 2022, ADLS is the only FAA approved light mitigating technology available to wind projects.
Light Mitigating Technology in Other States
Multiple states have instituted light mitigation requirements for wind turbines in recent years, among them are Colorado and North Dakota.
Colorado’s SB 22-110, effective August 10, 2022, applies prospectively and requires new wind-powered energy generation facilities to install light mitigating technology if vertical construction of the first turbine in the facility began on or after April 1, 2022. The bill defined technology as FAA-approved sensor-based systems that are designed to detect approaching aircraft and that deactivate when it is safe to do so.
North Dakota’s Public Service Commission established rules requiring turbines constructed after June 5, 2016, to have light mitigating technology. Enacted legislation soon followed in 2017 requiring every wind energy conversion facility that had been issued a certificate of site compatibility by the Commission before June 5, 2016, to be equipped with a functioning light mitigating technology system that complies with Commission rules by December 31, 2021.
Though ADLS is the only FAA-approved light mitigating technology currently available, new technologies may soon be used more widely. Companies have emerged offering alternative technology that dims FAA-approved obstruction lighting fixtures when the prevailing visibility conditions are favorable, returning the lights to full intensity when visibility conditions lessen or deteriorate.
It is unclear whether or when this type of technology will be approved by the FAA, and, if approval is received, whether FAA standards will need to be amended to accommodate for the addition.