Vineyard Wind To Test Long-Promised Lighting System

More than a full year after installing its first wind turbine off Nantucket, Vineyard Wind informed the town that it will be testing its long-promised aircraft detection lighting system (ADLS) next week.

The ADLS system has been a bone of contention as the lights atop Vineyard Wind's 800-foot turbine towers - which the company promised would remain dark unless an aircraft was passing by - continue to blink incessantly on the horizon. The safety lights atop the 24 turbines that have been installed to date have been an eyesore for many who enjoy Nantucket’s dark skies at night.

But on Wednesday, Nantucket Select Board chair Brooke Mohr said she spoke with Vineyard Wind CEO Klaus Møller, who informed her that the company was preparing to get the ADLS up and running this month.

"They are testing the first 12 sets of ADLS next week," Mohr said. "So we should expect the first 12 turbines to go dark at night with the ADLS system. What they’re doing is sending a helicopter over next week to test that. They expect to roll out another tranche of them the following month. I was told that every new turbine will have the ADLS come on when it’s commissioned, so as they’re building new turbines, they will have the ADLS functioning."

As part of Vineyard Wind's mitigation agreement with the town of Nantucket - a document better known as the Good Neighbor Agreement that was signed back in 2020 - the company is required to install a so-called Aircraft Detection Lighting System or ADLS. This system will utilize radar to ensure the lights at the top of each turbine activate only when there is an aircraft close to the wind farm area.

Vineyard Wind initially pledged to have the system operational by Memorial Day weekend of 2024. After that deadline came and went, the company pledged in June last year that the ADLS would be up and running “within the next several weeks.” Now, more than seven months after that statement, the system remains inoperative. 

The language of the Good Neighbor Agreement signed by Vineyard Wind and the town indicates that the ADLS is intended “to reduce nighttime lighting and minimize the potential visual impacts of the Projects on the Nantucket Historical District National Historic Landmark.”

According to the terms of the 2021 memorandum of agreement between Vineyard Wind, the Bureau of Ocean Energy Management (BOEM), and Brona Simon, the Massachusetts Historic Preservation Officer, “The ADLS must be installed and operational prior to commencing commercial operation.” Vineyard Wind announced back in January 2024 that it had delivered power to the New England power grid for the first time, but the company claims that does not represent commercial operation. 

"Vineyard Wind remains in full compliance with both the Good Neighbor Agreement (GNA) and the Memorandum of Agreement (MOA)," Vineyard Wind’s communications director Craig Gilvarg told the Current last September. "The MOA specifies that the ADLS will be activated prior to commercial operation of the project, while the GNA does not specify a time frame for the ADLS. The project has not yet achieved commercial operation under its PPAs."

According to Vineyard Wind’s memorandum of agreement with BOEM signed in 2021, the official description of an ADLS is a “sensor-based system designed to detect aircraft as they approach an obstruction or group of obstructions; these systems automatically activate the appropriate obstruction lights until they are no longer needed by the aircraft. This technology reduces the impact of nighttime lighting on nearby communities and migratory birds and extends the life expectancy of obstruction lights.” The company has asserted that once it is operational, it will be activated for less than four hours per year (less than .1 percent of the total annual nighttime hours) based on the historical use of the airspace above the Vineyard Wind lease area.