Timbermill Lighting Update (January 2025)

Due to interest from community members, we want to share an update with you about Timbermill Wind's FAA-required obstruction lighting. We understand that the project's lighting is a visual impact and appreciate the feedback we have received on this topic. The project team has investigated the concern and options to mitigate this impact
 
First, we want to be clear that we plan to apply with the FAA to install an Aircraft Detection Lighting System (ADLS) at Timbermill Wind. This radar-based system would keep the lights off unless aircraft are detected within a certain distance of the wind farm. From our initial stakeholder consultations, we believe ADLS at Timbermill Wind is viable and that an application for FAA consideration would be an appropriate path forward.
 
If permitted and built, this light-mitigating technology can reduce the amount of time that wind turbines are lit by as much as 98% compared to traditional FAA lighting.
We have reached out to several FAA-approved vendors for system information and pricing to identify the product that will be the best fit for the project based on topography, tree cover, and constructability.
 
Once a vendor is selected, we will work with them to prepare our application for FAA review of the proposed system. In order to submit the application, we will need to:
  • Identify an appropriate location for the ADLS radar tower
  • Secure permission from the landowner to install the tower on their property
  • Obtain any required state and local permits
We anticipate completing these pre-requisites in the next few months and hope to be able to submit our FAA application this Summer.
 
After submitting our request to the FAA, it will review and provide feedback before ultimately issuing letters either approving or denying the lighting plan for each turbine on a case-by-case basis (for example, it is possible for a single turbine to be denied ADLS, but still have it approved for the rest of the project).
 
The FAA review process typically takes 45-90 days between initial application and receipt of a determination.
 
During this time, we will also submit the ADLS lighting plan to the Department of Defense to ensure it complies with their rules surrounding military flight routes.


FCC Review

Following FAA review, the project will need to obtain additional approvals from the Federal Communications Commission. This is because ADLS radar operates on FCC licensed spectrum, requiring certain approvals to operate the radar. This part of the permitting process typically takes 3 months for most wind projects. Constructing an ADLS system at Timbermill may also require input from the U.S. Army Corps of Engineers.

Once all required permits are received, the system is cleared to begin construction. The ADLS construction process typically takes 9 months from start to finish.

Overall Timeline

We understand the desire to address this concern promptly, but we also want to be transparent about the permitting requirements and anticipated timeline.

Completing the required permitting steps will likely take anywhere from 6 to 12 months, followed by a 9-month construction period. Under that timeline, assuming the proposed system is approved, it would likely not be operational until Summer 2026.

This timeline could potentially improve if local and federal approvals come in quicker than expected. On the other hand, delays in federal action on wind-related permits could delay the process. Our commitment is to inform you of important steps in the process and updates as they come.

Alternative Proposals

We have received questions asking whether there are alternatives that could be pursued to mitigate visual impacts from the FAA lighting in the meantime. We wanted to specifically address these suggestions to correct misconceptions about what may be possible.

Light Dimming Technology

At this time, there are no other FAA-approved light mitigating technologies besides ADLS. There are companies working on different technologies to mitigate nighttime lighting, such as light dimming technologies where lights are always blinking, but brighten only when aircraft are approaching. However, the FAA has not yet certified any light mitigation technology other than ADLS, nor have they provided guidance for how these systems would be implemented, if approved.

The types of lights used, as well as the frequency of the lights (blinking every 2 seconds) is required under FAA rules.

Quadrant Lighting

Because the wind turbines at the project exceed 500 feet in total height, quadrant or perimeter lighting (where only a portion of the turbines are lit) is not permitted by the FAA. All turbines are required to light up in unison.

There is an FAA variance process where this could be explored further if the ADLS application is not approved, but we are not aware of other wind projects receiving an exemption from this rule.

Next Steps

Our team will turn our focus to selecting a vendor, working with them to design the ADLS system, and preparing our FAA application. We plan to send an additional update e-mail by the end of April, or when the application is submitted, whichever comes first.

We appreciate your patience as we pursue adding this system, which, once implemented, is expected to dramatically reduce the amount of time the turbines are lit.

In the meantime, feel free to contact us with additional questions via this e-mail address, or through the project website. To learn more about wind energy lighting and ADLS, click here to download a one-pager on the topic.