Why the Vineyard Wind Blade Broke

The blade that snapped off an offshore turbine at the Vineyard Wind project in Massachusetts on July 13 broke due to a manufacturing defect, according to GE Vernova, the turbine maker and installer.

During GE’s second quarter earnings call on Wednesday, CEO Scott Strazik and Vice President of Investor Relations Michael Lapides said there was no indication of a design flaw in the blade. Rather, the company has identified a “material deviation” at one of its factories in Gaspé, Canada.

“Because of that, we're going to use our existing data and re-inspect all of the blades that we have made for offshore wind,” Strazik told investors, adding that the factory has produced about 150 blades total.

Company executives shared more details about their findings at a public meeting in Nantucket on Wednesday night. Roger Martella, GE Vernova’s chief sustainability officer, said there were two issues at play. The first was the manufacturing issue — basically, the adhesives applied to the blade to hold it together did not do their job. The second was quality control. “The inspection that should have caught this did not,” he said. “So it’s a combination of the two factors.”

Two dozen turbines have been installed as part of the Vineyard Wind project so far, with 72 blades total. GE Vernova has not responded to requests for clarification about how many of them originated at the Gaspé facility.

The re-inspection process does not involve physically inspecting each blade, Martella explained. The company takes “incredibly detailed ultrasound pictures” of every blade it produces, he said, and will be reviewing the images as “a desktop exercise.” He likened the process to getting a second, more detailed opinion from a doctor on an MRI. When asked why the company did not catch the defect the first time these scans were inspected, Martella said answering that is part of the ongoing investigation. In the meantime, blade production at the factory is on pause.

GE also stressed that the incident at Vineyard Wind was unrelated to a blade failure at the Dogger Bank wind farm in the U.K. earlier this year, which was due to an installation error. Installation has resumed at Dogger Bank.

Tensions were high at Wednesday night’s meeting, where Nantucket residents again lined up to lambast Vineyard Wind. Select Board chair Brooke Mohr opened the meeting by saying that the incident has shown the inadequacy of the Good Neighbor Agreement , a settlement between the town and Vineyard Wind reached in 2020. Under the agreement, the company would contribute $4 million to a community fund and take steps to minimize visual impacts of the wind farm. In return, the town would “convey support” for the project to the community and to state and federal officials. Mohr said the town now intends to renegotiate these terms. “The Select Board is committed to holding vineyard wind and GE, the manufacturer of the turbine blades, accountable,” she said.

Town representatives are going to meet with Vineyard Wind next week to negotiate compensation for the costs it has incurred as a result of the accident.

Meanwhile, on the ground and in the water around Nantucket, crews from Vineyard Wind and GE continued to collect blade debris on Wednesday morning, for the ninth day straight. An initial environmental assessment of the blade debris published late Tuesday night began to answer key questions about the risks all that debris poses to people and marine life.

The report was commissioned by GE and conducted by Arcadis US, an engineering and environmental consultancy. It asserts that the primary risk to people is injury from the sharp edges of fiberglass fragments and that the debris “are considered inert, non-soluble, stable, and nontoxic.”

It also cautions, however, that further evaluation will be required to understand the risks posed by any blade materials that remain in the environment, such as assessing the potential for degradation. At the meeting in Nantucket on Wednesday night, one resident asked whether they should be worried about eating fish or shellfish that may have ingested pieces of the blade. Jim Nuss, one of the authors of the Arcadis report, said the firm had “not considered that yet,” and that it would be “one of the future looking activities.”

One particularly concerning question has been whether the debris could discharge dangerous per- and polyfluoroalkyl substances, also known as PFAS or “forever chemicals,” into the environment. Though there are no PFAS used in the blade construction itself, the firm did identify the chemicals in “aerodynamic add-ons,” small 6 inch by 8 inch pieces of plastic that are installed on the outside of the blade to improve its efficiency that are also commonly used on airplanes, it said.

According to the report, the total amount of PFAS on one blade equals 28.2 grams, or about 0.06 pounds. To put that in perspective, the chemical company Daikin once estimated it would release roughly 200 pounds of PFAS per day into the wastewater at one of its paper mills, according to federal filings obtained by the Environmental Defense Fund in 2018. It’s not yet clear how many of those plastic “add-ons” made it into the ocean.

A comprehensive list of all materials that make up the blades shows that more than half, by weight, is fiberglass. The other key ingredients include carbon fiber and PET foam , a common construction material. “There are 33 different materials involved in the production of a turbine blade, from the most basic common household adhesives to the more complex industrial materials used to build the blade,” the report says.

An introduction to the report notes that GE is creating an inventory of the debris collected to assess how much of the blade has been recovered. The company has also hired Resolve Marine, a marine salvage firm, to aid in dismantling the remainder of the blade that’s still attached to the turbine, though it didn’t offer a timeline for this work.

Editor’s note: This story has been updated to reflect the events of the July 24 Nantucket Select Board meeting.

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