Kansas, Washington Take Aim at Wind Turbine Lights

As wind turbines become increasingly common sights on the global landscape, concerns have emerged about their impact on wildlife and human health. One issue that has arisen is light pollution. Light abatement or mitigation has become an important concern for the wind industry, as it seeks to address these concerns and reduce its impact on the environment and communities. In some cases, this is being driven by legislation. In April, a bill in Washington state for light mitigation of wind turbines was on its way to the governor after passing through the state's Senate and House, while in Kansas, the governor signed a bill requiring developers to install light mitigation technology on new and existing windfarms if approved by the U.S. Federal Aviation Administration (FAA).

Light pollution from wind turbines typically takes two forms: blade flicker and nighttime lighting. Blade flicker occurs when the rotating blades of the turbine pass in front of the sun, creating a strobe-like effect that can be disorienting and dangerous for wildlife and people. Nighttime lighting makes the turbines visible to aircraft but can also cause disturbance to local communities and disrupt natural ecosystems. The bills in both Kansas and Washington take aim at the use of nighttime lighting.

To address these concerns, wind turbine manufacturers have developed a range of light abatement technologies that aim to reduce the impact of turbine lighting on the environment and communities. One approach is to use sensors and computer systems to automatically adjust the lighting of the turbines based on ambient light conditions, minimizing their impact while maintaining visibility for safety. This approach is known as adaptive lighting and has been implemented on some wind turbines.

Another approach is to use specialized lighting that is less intrusive and less harmful to wildlife. This can include amber-colored lighting that is less attractive to insects and other nocturnal wildlife, as well as low-intensity lighting that is less disruptive to nearby communities. Such lighting solutions have been found to be effective in reducing the negative impacts of nighttime lighting on the environment.

The Kansas and Washington bills are geared toward installing aircraft detection lighting systems that rely on radar to turn the lights on if an aircraft is detected and turn them off after it has passed.

At the time of writing, the light mitigation bill was on Washington Governor Jay Inslee's (D) desk to be signed into law. If he does so, the law would take effect for new windfarms with five or more turbines in July, while older windfarms must install the lighting systems by 2028.

If the bill becomes law, examples of projects that could be affected by the new legislation include Scout Clean Energy LLC's (Boulder, Colorado) Horse Heaven wind project. As planned, the windfarm would include 248 turbines to achieve a nameplate generating capacity of 350 megawatts (MW). Construction is set to begin in 2024 and expected to begin completed by the end of the year. Subscribers to Industrial Info's Global Market Intelligence (GMI) Power Project Database can click here for the full report.

The U.S. Midwest is a hotspot for windfarms, and Kansas boasts no less than 4,000 turbines in operation, according to regional news media. Kansas Governor Laura Kelly (D) signed the Kansas turbine lighting-mitigation bill into law in mid-April. The law requires that starting July 1, developers of windfarms with at least five turbines must apply to the FAA for approval to use a mitigation technology that complies with the agency's regulations. If approved, they would have 24 months to install it.

The law functions a bit differently for the state's operational windfarms. Starting July 1, 2026, windfarm owners and operators must apply to the FAA within six months of signing a new power offtake agreement. Because this could potentially mean a decade or more of waiting for light-mitigation technologies to be installed at existing windfarms, the law includes a provision allowing counties to use bonds to help pay for the technology earlier than the law would require.

Several windfarms are proposed to begin construction in Kansas after the July 1 date. Among them is Enel Green Power North America's (Andover, Massachusetts) Skyview Development Windfarm near Concordia. The facility would use 60 wind turbines to achieve a nameplate generating capacity of 180 MW. Construction is set to begin next year and be completed in 2025. Subscribers can learn more by viewing the project report.

While blade flicker during the day appears to be a less pressing concern, manufacturers are taking note by experimenting with blade design that reduces the flicker effect. By altering the shape or angle of the blades, the strobe effect can be reduced or even eliminated.

While light abatement technologies have shown promise in addressing the concerns of light pollution from wind turbines, there is still much work to be done. The wind industry will need to continue to invest in research and development to refine these technologies and make them more effective. Legislation, such as that passed by Kansas, Washington and other states, may be a significant driver in these developments.