Vineyard Wind Update: A Letter from the Select Board

Open Letter to the Nantucket Community from Chair Mohr, on Behalf of the Nantucket Select Board, Regarding Lighting Associated with the Vineyard Wind Project

The dark night sky is fundamental to Nantucket's character, sense of place, and cultural heritage. As your elected leadership, it is our responsibility to fight for our community and protect what makes us unique. Because the Town is not empowered to prevent offshore wind development, which is under federal and state jurisdiction, we have focused on minimizing adverse impacts to Nantucket from these projects.

Four years ago, the Town negotiated directly with Vineyard Wind to secure its agreement to install Aircraft Detection Lighting Systems (ADLS) on the offshore turbines that occupy our horizon. ADLS will reduce lighting on the Vineyard Wind project from a constant, year-round blinking to less than an aggregate of one day a year. Although ADLS has recently become a standard feature for offshore wind development, it was not standard when we were at the negotiation table four years ago. BOEM was not going to require this technology of the developer, but we saw it as vital to reducing intrusion on the darkness of our skyscape. After Vineyard Wind agreed to our demand, BOEM included it in the permit conditions. Nantucket's advocacy has resulted in ADLS implementation as an industry best practice.

We recognize there is some confusion surrounding ADLS-what it is and is not-and what to expect going forward. We provide additional information below.

What is ADLS?

ADLS is an aviation safety lighting technology that detects oncoming aircraft and turns on FAA-required aviation obstruction lighting only when the aircraft is within 3 nautical miles (3.45 statute miles) of the turbine. This technology substantially reduces the appearance of red blinking lights from continuous 365 days a year to an aggregate of less than 1 day (As stated on p. 5 of the Section 106 Memorandum of Agreement between federal and state regulatory agencies and Vineyard Wind LLC) For aviation safety, it is not possible to omit the warning lights entirely, but ADLS reduces them by up to 99%. The system will be monitored 24/7 by Vineyard Wind personnel.

Which lights are reduced?

ADLS addresses the lights most visible from shore: the red flashing warning lights at the top of each turbine nacelle, 451 feet high. It also controls the flashing low intensity lights midway between the top of the nacelle and sea level (see diagram below). When activated, the aviation safety lights will flash 30 times per minute. Limiting these lights will greatly reduce the visibility of the turbines at night. Coast Guard regulations still require lights at all times at the base of the turbines for maritime navigational safety. Construction lights are also not addressed by ADLS. Vineyard Wind WTG Aviation Obstruction Lighting Design Plan, Attachment 3 of the Memorandum of Agreement.

When will ADLS be implemented?

Vineyard Wind is contractually obligated to have the system in place once the project is commercially operational. The developer and BOEM may have different understandings of what commercially operational means, which is contributing to confusion as to the deadline for implementation. The Town has urged Vineyard Wind and BOEM to reconcile their understanding so that Nantucket residents may have clear and accurate expectations.

According to Vineyard Wind, it was close to implementing ADLS for the first stages of the project-in advance of their contractually required deadline-before the blade failure. The developer is collaborating with contractors to overcome technical issues and ensure the system is activated as soon as possible if, and when, construction resumes.

The Town regularly monitors the project status and reiterates how important the ADLS feature is for our community.

Do you have more questions about the project? Please refer to the online resources the Town provides at: www.nantucket-ma.gov/offshorewind.

Signed,

Brooke Mohr, Chair

Nantucket Select Board