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EPIC Tours Atlantic Offshore Wind Farm

Vineyard Wind 1 in April 2024.
Vineyard Wind 1. Photo by Tom Wheeler / EPIC.

Last week, I had the privilege of visiting Vineyard Wind 1, an offshore wind farm under construction off the coast of Martha’s Vineyard, Massachusetts. When completed, Vineyard 1 will be the largest offshore wind project in the United States, with a nameplate capacity for 804 megawatts (MW) of electricity — enough power for some 600,000 homes. Humboldt’s proposed offshore wind farm would be far bigger and more powerful, with a likely capacity in excess of 2.6 gigawatts (GW), or 2,600 MW.

For full disclosure: I attended this trip with a delegation of guests from Humboldt County, including Tribal representatives, workforce and economic development representatives, elected officials, and staff from Humboldt County, the Redwood Coast Energy Authority (RCEA), and the Humboldt Bay Harbor, Recreation & Conservation District. Travel costs were mostly borne by a grant received by Humboldt County, although EPIC did pick up some other incidental costs. Besides a free hat and tote bag, EPIC received nothing of material value. (Anyone need a free hat? My head is too big.)

Not All Offshore Wind is the Same

While visiting Vineyard 1 was interesting, it also clearly highlighted how not all offshore wind is the same. The shallow continental shelf of the East Coast, with depths of only ~100 feet almost 20 miles offshore, allows for fixed-bottom wind energy platforms with long steel columns that connect turbines to the ocean floor. In vast contrast, the continental shelf drops off considerably off the West Coast, with the depths of over a half-mile inHumboldt’s wind energy area, requiring the use of floating platforms for offshore wind turbines. The distinction between fixed and floating offshore wind infrastructure makes a large difference in the kinds of environmental impacts one might expect from coastal wind energy development.

Most of the construction activity for fixed-bottom turbines occurs at sea and port operations are mostly preparing components for installation.
Most of the construction activity for fixed-bottom turbines occurs at sea and port operations are mostly preparing components for installation. Photo by Tom Wheeler / EPIC.

Fixed-bottom turbines are constructed at sea. This begins with construction, where pile driving activity sinks foundation pieces directly into the ocean floor. Pile driving is noisy work and can impact whales and other marine life. To mitigate those impacts, pile driving activity is restricted to times of the year where it will be less impactful, with sound dampening technology (like bubble curtains) employed.

By contrast, floating offshore wind turbines are mostly constructed in harbor, with land-based cranes placing sections of wind turbines on top of floating platforms. At this time, it is likely that turbine construction for the Humboldt Wind Energy Area will be completed in Humboldt Bay. Impacts associated with floating turbine construction include habitat loss from dredging and a risk for expansion of invasive species brought in on ships with turbine parts. Mitigation measures can reduce, but not eliminate these threats. EPIC and our allies have successfully pushed for the Humboldt Harbor District to commit to a “green port” strategy that will require construction activities to reduce avoidable air quality impacts to the maximum extent possible throughout the life of the port, primarily through the electrification of port infrastructure.

Marine Mammal Protections

This heavy-lift ship is suspended off the water. It installs the turbine components on top of the foundation pieces.
This heavy-lift ship is suspended off the water. It installs the turbine components on top of the foundation pieces. Photo by Tom Wheeler / EPIC.

From my visit on the East Coast, I left encouraged by the efforts taken to reduce impacts to marine mammals. All vessels associated with offshore wind activities are required to use “protected species observers,” which are trained professionals who are on the lookout for protected marine species. If spotted, all activity basically stops until the species has left the area.

There were a number of alarmist news articles last year that attributed, a slate of whale deaths on offshore wind—all unsubstantiated by real scientific data. Necropsies and other research determined that ship strikes and line entanglement, not at all related to offshore wind, were the primary anthropogenic causes of whale deaths. Ironically, warmer ocean temperatures caused by climate change—which offshore wind energy is posed to help alleviate—is believed to have played a role changes to whale behavior that increased their risk of human-caused injury from sources unrelated to offshore wind.

In California, the Coastal Commission has imposed speed limits on offshore wind vessels. Together with protected species observers, the risk to whales by additional ship traffic from offshore wind is low. Steps have also already been taken to reduce secondary entanglement risks to marine mammals from crab and fishing gear, such as seasonal closures when whales are present. 

Another concern for whales due to offshore wind development is sonar technology used in site assessment activities by wind energy developers to study the ocean floor for potential environmental impacts. Good news, though—RWE, one of the two wind energy developers for the Humboldt Wind Energy Area, has agreed to use lower-impact underwater drones. Because they operate closer to the ocean floor, the noise emitted by their sonar arrays is much less impactful than more traditional sonar systems. 

Turbine Size Matters

Vineyard 1 uses 15-MW General Electric ​​Haliade-X turbines, the largest commercially available wind turbines in the United States, which measure roughly 812 feet tall at the very tip of a turbine blade. It is currently unknown what size turbine will be used for the Humboldt Wind Energy Area, but they will likely be larger. A conceptual Chinese model of a 22-MW turbine has a roughly 1000-foot blade height, and hopes for Humboldt turbines are for turbines exceeding 20 MW. And with wind turbines, size matters — larger turbines produce way, way more power. For example, roughly 200 additional feet of turbine rotor diameter yields an additional 9 MW of power, or about enough for 6,750 homes (roughly Rio Dell, Garberville and Redway combined). Larger turbines also reduce operational costs, allowing electricity to be delivered more efficiently. 

Up close, the turbines were large—but I expected them to feel larger and more imposing than they really are.

Wind turbine at approximately one nautical mile away.
Wind turbine at approximately one nautical mile away. Photo by Tom Wheeler / EPIC.

What might offshore wind turbines look like on the North Coast horizon? According to visualizations that show the view from Sue-meg State Park, coastal haze will make them virtually impossible to see on most days.

Visualization of the Humboldt Wind Energy Area provided by the Bureau of Ocean Energy Management

But I wanted to see for myself, so I took this photo of the wind farm approximately 20 miles off the coast of Massachusetts. The turbines are visible, though barely.

Can you see the turbines?

At night, the turbines are equipped with sensors to determine whether planes are in the vicinity, which automatically activates the red FAA hazard lights. According to Vineyard, they project that the lights will only be on for four hours a year. There are no estimates yet for Humboldt, as that data will be presented in a future EIS for wind energy operation.

While EPIC is already deep in our investigation of offshore wind, we are actually quite early in the development process, with the earliest estimates of operation in 2035. Wind energy developers are only now starting their site assessment activities. 

If you have any questions about offshore wind, send them our way and we will try our best to answer them. Matt Simmons, EPIC’s Climate Attorney, can be reached at


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