A submerged concern: offshore wind cables 

While turbines turn heads, cables are also a major part of offshore wind projects.

By
Eunki Seonwoo
-
51
This graphic shows a couple of the routes that offshore wind cables may travel. The green line shows a corridor in Muskeget Channel that already has cables from Vineyard Wind 1 with more cables on the way expected for New England Wind, totaling up to seven cables. The blue line is a potential cable route for SouthCoast Wind's second phase. —MV Times

As offshore wind turbines undergo construction in waters south of the Vineyard, and with some already standing and delivering power, the debates on the Island regarding the industry continue. 

And amid the conversations over a necessity for clean energy, and whether the projects are a blow to the Vineyard’s natural charm — coupled with a mix of online misinformation campaigns against the offshore wind industry — one subject has remained submerged: undersea cables. 

While cables — which connect wind farms to the New England power grid on the mainland — aren’t the flashiest parts of an offshore wind farm operation, some are nervous about what may lie ahead with them. 

John Keene, president of the Martha’s Vineyard Fishermen’s Preservation Trust, told the Times that some in the fishing industry are nervous about how the electromagnetic field from the cables can affect marine life. 

Keene said the concern is that the fields emitted from cables could act like a fence, particularly for migratory species, and impact the behavior of marine species. 

“There’s a lot of unknowns,” he said.

The worry also stems from how many cables would be in areas not far from the Vineyard, including a spot near Edgartown called Muskeget Channel. Seven cables are planned to go through one of the channel’s corridors.

“The collective energy hasn’t been met yet,” Keene said regarding the number of cables that would be on the seafloor once the offshore wind farms planned south of the Island are completed. 

There are nearly 10 offshore wind projects underway or proposed in seas south of the Vineyard, which have terms of around three decades per lease area.

Among the various offshore wind projects within 30 miles of the Vineyard, the 130-megawatt South Fork Wind project, located around 20 miles southwest of Martha’s Vineyard, is the only one that has completed construction so far, and is delivering power through cables that come to shore in Long Island. 

For Vineyard Wind 1, an over 800-megawatt, 62-turbine offshore wind farm in the works, overseen by Avingrid, the cables come close to Edgartown. 

Vineyard Wind 1’s 220-kilovolt undersea cable slithers over 15 miles through a corridor in Muskeget Channel before making landfall in Barnstable, partially passing through waters under Edgartown jurisdiction.

And it’s not the only undersea cable laid by Avangrid in the channel. The corridor, generally 3,800 feet in width, was previously widened by around 1,000 feet by developers for cable laying, and may be completely filled out by cables stemming from Avangrid projects, including a lease area for a proposed offshore wind operation collectively known as New England Wind.

An Avangrid press release touting the projects’ potential economic and environmental benefits to the region says that Park City Wind is returning as the 791-megawatt New England Wind 1 and Commonwealth Wind is coming back as the 1,080-megawatt New England Wind 2. 

The cables for Vineyard Wind 1 and New England Wind projects are each around 11 inches in diameter, and will be, or currently are, buried five to eight feet below the sea floor. Despite the small amount of space the cables themselves would take up, Avangrid representatives and consultants have said that a large amount of space — between 164 feet and 328 feet — is needed between each cable to keep them from damaging one another, and for repair vessels. 

The New England Wind 2 connector cable — which consists of 275-kilovolt cables — is currently under review by the Martha’s Vineyard Commission. During a public hearing on April 11, the only public comments to the commission came from board members of Vineyard Power, a partner of Vineyard Wind. 

Although commissioners have yet to make a final decision, there were questions whether the cable construction would affect marine life, and who would be liable if something went awry while laying the cables. 

Even if the MVC approves the project, Avangrid will still have more steps ahead. Edgartown conservation assistant Kara Shemeth tells the Times the cable project would return to the town’s conservation commission after undergoing MVC review. 

And the approval process may not encounter smooth sailing with the Edgartown conservation commission. The conservation commission had denied permitting undersea cables for Vineyard Wind 1 and the former Park City Wind project, although the state’s Department of Environmental Protection ultimately reversed these decisions. 

Both times, the conservation commission expressed concerns over potential environmental impacts from the cables. A representative of the Edgartown commission was not immediately available for comment. 

Bureau of Ocean Energy Management (BOEM) spokesperson Brian Walch told the Times that the agency works closely with tribes, government agencies, and a “wide range of other ocean users” to make sure offshore energy development is done in a “responsible manner” that would avoid or mitigate potential impacts to offshore environment and marine life. 

As for the electromagnetic fields, Walch said that the cables are wrapped in sheathes that reduces the emission of these fields. Additionally, Walch said, the fields decay quickly with distance from cables, and burying them reduces potential exposure. 

Regarding the impact on marine species, electromagnetic fields exist naturally in the ocean, but are also generated by other types of cables, like those for telecommunication. Additionally, the power company Eversource has undersea cables connecting the Island with the mainland for power distribution that make landfall in Tisbury, Oak Bluffs, and Falmouth.

BOEM also states that the alternating current from the offshore wind cables in Southern New England “will generate weak EMF at frequencies outside the known range of detection by electrosensitive and magnetosensitive fishes.” 

Walch said while some species, like skates, sharks, and lobsters, are sensitive to electromagnetic fields, “detrimental effects to populations are not expected.” 

“Some marine species are observed to respond to EMF, but the fields do not negatively impact their movement,” Walch said. 

Developers for the New England Wind 2 connector cable project also said there would be no permanent changes caused by the construction. However, laying the cables may require dredging more than 100,000 cubic yards of sand, which may kill some shellfish, like surf clams and young blue mussels. MVC staff stated during the meetings it could take up to four years for the affected sea life to recover and recolonize, depending on the seafloor composition. Maritime navigation and fishing activities near the cable-laying area will also likely be impacted while construction takes place. 

Island commercial fisherman Wes Brighton told the Times that the number of undersea cables would be an unprecedented amount for the waters near the Vineyard, adding it may be too early to tell exactly how local waters will be impacted.

“To speculate as to what the impacts and the damages are, there’s no empirical data that you can be sure of what the outcome is, so it’s very problematic from a mitigation perspective,” he said, adding he feels the potential impact could be “catastrophic.” 

But Brighton also said this remains uncertain until more time has passed observing the areas for changes. He will be on notice during the upcoming commercial conch and squid seasons, after the cables have been laid.

The connector cable project representatives also stated there would be no damages to undersea archaeological sites, a concern The Times has heard from the Wampanoag Tribe of Gay Head (Aquinnah) before. Walch said BOEM encourages developers to avoid or minimize impacting underwater cultural resources, and the agency consults tribal nations on a “government-to-government basis” for input about sites of significance. 

Walch noted that BOEM requires developers to follow their procedures to preserve submerged archaeological sites and cultural resources during construction, and to add buffers around these areas. 

“Also, protocols are in place for ceasing construction in the vicinity of an unanticipated archaeological discovery, as well as for notifying BOEM for the discovery immediately,” Walch said. 

Avangrid-owned cables aren’t the only ones that may be coming close to the Vineyard. While SouthCoast Wind is proposing a cable that runs south of Nomans Land and making landfall in Somerset, another cable proposed for its second phase could be connected in Falmouth, with a cable route that would run even closer to the Island than Vineyard Wind 1’s cable. 

While fishermen have been appreciative of Vineyard Wind coordinating before construction, some are unsure whether other companies with projects south of the Island would be as proactive. 

“Each company handles how they do outreach differently,” Keene said, pointing out that various projects were in different permitting stages. 

Some companies haven’t done much outreach, Keene noted, like representatives for South Fork Wind. South Fork Wind is jointly owned by Ørsted and Eversource. The two companies also jointly owned Revolution Wind and Sunrise Wind, although Eversource relinquished its shares of these projects earlier this year. 

Although not the only company owning projects in waters south of the Vineyard, Ørsted is the one company that rivals Avangrid in the number of projects planned in the maritime region. 

Addressing some of the concerns raised, an Ørsted spokesperson stated, “We’ve taken a number of steps to ensure the coexistence of the commercial fishing industry with offshore wind — often by being directly responsive to requests from the fishing community. Our outreach work has included fishers in Massachusetts, and specifically on Martha’s Vineyard.”

The spokesperson pointed to several ways Ørsted has engaged with the fishing community, like a direct compensation program to commercial fishermen impacted by the South Fork Wind project, committing over $3 million in coastal community funds in Massachusetts and Rhode Island, and committing $2.3 million toward a “navigational enhancement and training program” to help commercial vessels acquire navigational equipment and access to professional mariner training. 

When asked about the concerns surrounding undersea cables, Avangrid chief development officer Ken Kimmell pointed out that the offshore wind cables would not be the first of their kind. “This happens literally all over the world,” Kimmell said.

Kimmel emphasized that when offshore wind projects are planned out, developers are asked to designate a corridor to place the cables rather than laying them all over. He said these areas are “studied intensely,” and that Muskeget Channel was “ideal” as a cable-laying location because it was not used as intensely as a fishery. 

Additionally, Kimmel said Avangrid would employ jet plowing, which he described as a cable-laying method that would have a minimized impact on the environment. 

The record of decision from BOEM goes into detail about the cable-laying process, Kimmel said, and added that Avangrid had essentially received the “green light” from state entities for its projects. 

“We’ve addressed all relevant environmental concerns,” he said.

Back on the Vineyard, Brighton emphasized that fishermen are not climate change deniers. Some in the public have pointed at fishermen as climate deniers for their outspoken criticism of the offshore wind industry. Rather, Brighton and other fishermen wish that more consideration and collaboration had taken place before the offshore wind projects were approved. 

He pointed to how Vineyard Wind’s compensation program requires commercial fishermen to have fished in the lease area for at least three years between 2016 and 2022, but fisheries experience booms and busts that can keep commercial fishing operations in other parts of the ocean. 

“As fishermen, we’re witnessing change,” Brighton said.

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51 COMMENTS

  1. Horrifying. They’re NOT ” unknowns”. Anyone who is naïve enough to think that this was a fine idea has a serious disconnect problem. Nice work, Homo Insapient.

    • Martha– we actually know that the EMF’s are very weak and affect very few things.
      if you have any verifiable evidence to the contrary please post it.
      A pox on misinformation !

    • Martha, how does electricity get to the Island?
      What is known?
      Is it a fine idea?
      Should the those cables be torn out?
      Generate the Island’s power on Island?
      Wind, solar, gas, Bunker C or coal?

  2. It is not Martha’s Vineyard anymore!
    Ever since Kennedy (D) killed Mary Jo on Chappy and our beautiful island was put on the map, it has continually gone downhill in every way!!!😡
    And for those who say “If you don’t like it, just leave”!
    Well my myself, our daughter, both my parents, my grandparents etc are from here so just **** off!!

    • It is is not the same Martha’s Vineyard where you were born.
      Like all the universe the Island will continue evolve.
      If you don’t like it, your only choice is to leave.
      Well you, your daughter, both your parents, your grandparents etc are from here so just **** off Island.
      The Island has way too many malcontents.

  3. I honestly don’t understand why BOEM wouldn’t stop at the first 2 projects (VW1 and South Fork) and learn from their impacts on the ocean environment. These projects are unlike anything in Europe. Push pause, learn, do the work and research and then if warranted move forward. The project documents claim no benefits to climate
    Change. There is no reason to move so fast- oh wait- follow the money – and tax credits.
    https://nap.nationalacademies.org/read/27154/chapter/1#v

    • Veronica, according to the National
      Academies of Engineering,
      warming ocean water is a problem.
      The warming of ocean water originates
      from burning fossil fuels. We need
      Windmills and Solar, and we needed
      them yesterday. We need to move
      Quickly to save the lobster 🦞
      (If there are any left).
      “Major oceanographic changes have occurred in the region since 2000, including warming of surface and bottom temperatures, increased frequency of Gulf Stream warm core rings, and midwater intrusions into the tidally mixed inshore region. Warming water temperature affects onset, decay, and intensity of seasonal stratification”
      National Academies of Sciences, Engineering, and Medicine. 2024. Potential Hydrodynamic Impacts of Offshore Wind Energy on Nantucket Shoals Regional Ecology: An Evaluation from Wind to Whales. Washington, DC: The National Academies Press. https://doi.org/10.17226/27154.

    • Veronica, the people who live near oil refineries
      have higher rates of asthma.

      https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3373279/

      Imagine this picture: a windmill has
      wind coming in one side and money
      pouring out the other side.
      Who wants to stop windmills?
      The oil companies. And the oil companies
      are willing to fill up social media with
      Lies to convince people how bad
      Windmills are for you and lobsters 🦞.
      Would you rather have your children
      or grandchildren living next to
      windmills or oil refineries?

    • Very long article, what is your take away?
      Are oil production platforms more harmful to the environment?
      The burning of oil?
      What about the burning of wind energy?

  4. How is the electromagnetic field from a cable from a wind farm different from a cable from the grid?

    • Dolores — Do you know that cell phones produce an emf
      field ? Also — every overhead power line also.
      Actually any electrical device.

    • How is the electromagnetic field from a cable from a wind farm different from a cable from the grid?
      Does our current cable to the mainland make you sick?
      Would generating all power consumed on Island being produced on Island make you sick?
      Does seeing the means of producing electricity make you sick?

  6. I think the problem here is the cumulative effect.Not just 1 cable running through Muskegett channel but multiple cables, not 1 cable connecting the turbines but 10 thousand plus miles. The same can be said for the turbines themselves, not just 10 or 12 of them planned but 100s up and down the coast.
    BOEM -URI conducted studies of the EMFs associated with the cables and found that certain species will avoid the cable areas and also known to kill off Krill , which is a major food source for the North American Right Whale.
    Here again, I think it it’s the mass scale of these projects at an expedited rate to bring to completion. Species don’t have much time to adapt. We witnessed this last summer when mono pile driving was occuring.
    Time will tell.https://www.sciencedirect.com/science/article/pii/S0269749124002847

    • Jason. Thank you for the link. It is very informative.
      But it is long and detailed so I only had time to skim it.
      I didn’t see anything mentioned about krill.
      I bookmarked it for later reading.
      But I did look up the life cycle of krill.
      They spend most of their time near the surface, where EMFs would be
      negligible to non existent. There is a direct inversely squared proportion to distance.
      That is that if you double the distance from the source, the amount ot uT
      radiation is reduced by an inverse proportion of the square rt.
      That may not be the proper way to phrase that, but it should
      suffice. So it would seem that krill would not really experience
      much of the fields.
      But krill do vertically “migrate” on a daily basis, perhaps bringing them
      close to the seafloor for a portion of the day. Where they could
      be affected. Or not.
      I found this one that you might like;
      https://espis.boem.gov/final%20reports/5659.pdf

      I would be interested if you could find something more detailed about the
      emf effects on krill. Especially about fields strong enough to kill them.
      Thanks.

  7. If we’re so worried about the krill, whales, and lobster 🦞, then why are we allowing any fishing at all?

  8. “Additionally, the power company Eversource has undersea cables connecting the Island with the mainland for power distribution that make landfall in Tisbury, Oak Bluffs, and Falmouth.” Just one sentence concerning the cables that have supplied electricity to the Island for decades and have never been a source of controversy except when one of them fails. You’ve had years and years to study their effects on ocean life and fishing. And the data says?

  9. Especially when the FOOD SOURCE will diminish. Who’s going to pay the price for that. So sad 🙁

  10. High levels of EMFs or long term exposure can cause health problems in some people, so why not marine life? Hard to argue with utterly unqualified geniuses, an inability to have compassion for anyone not on a “what’s cool” list, and a hypocritical political agenda, though.

    • Should the existing cables to the Island be removed?
      They have been there long term.
      Have they impacted the fish?
      The political agenda is to reduce hydrocarbon pollution.

      You bit on the clickbait.

  11. Another click-baitey article looking to catch people’s attention instead of actually reporting. There’s good science that shows there are negligible effects to EMFs. Any effects are being reduced. The BOEM has regulations. Offshore wind energy is NOT NEW (to the world). Perhaps this one of the aforementioned “disinformation campaigns?” The only solid takeaway from this article is that fishermen want better communication and leverage in the decision making with offshore wind companies—so why give it a headline about undersea cables? Disappointed with this one MVTimes…

    And to the people in these comments that aren’t fishermen and are still complaining about the “bad views,” these wind farms are what true justice looks like. Millions of underprivileged people are exposed to forms of energy production (that supply each and every one of your existences) that are actually directly harmful to their health, and meanwhile you all are coming up with fake reasons to say “Not in my backyard!” It’s time to look at these wind farms with a little more nuance people. Yes, they need to communicate with fishermen better, but they are our nation’s first huge step towards just and equitable clean energy.

  12. This article was poorly researched. The author doesn’t seem to understand electricity. This idea that cables creating a barrier is just plain nonsense. The electromagnetic field of shielded cables is non existent. The unshielded 3 phase power on overhead lines snaking around the island will produce more of a EMF than those undersea cables. The wall plug near your head will produce more of a field. Solar radiation produces a magnitude more EMF than these cables or our powerlines. The other erroneous thought that has been making the rounds on social media is that we can get breaks in the cables and that will effect the marine ecology. This stems from a misunderstanding of what electricity is and how it moves. It’s not like an oil line that when it breaks spills it’s contents into the ocean. Any breaks in the line and power stops flowing…period.
    .

  14. Jason,
    The study concluded no statistically significant impact. I think that the cumulative effect of fishing boats and the activities of fisherman and shipping in general would have a much higher impact than what was seen in the study. Both of the studies were outside harbors. New York and New Haven. The study says that just using an enclosure had an effect on the species studied. It’s conclusion was that “both the lobsters and skates made full use of the enclosure space and the cable did not present as a barrier for either species”. Fishermen have a much larger effect on ocean species than the cables.

  15. Chris – EMFs are NOT non existent , yes they may be low but do exist. However, some species can be significantly effected by even the lowest emission.
    Lobsters , skates and other bottom dwellers leave the areas where the EMFs are present, crabs refuse to bury in the bottom….read links I posted here. Keep an open mind.
    Also , please explain how the energy stops flowing if there’s a breach in the cable?
    I fished for conchs where the cable comes in from Falmouth into vineyard Haven outer harbor about a mile out. There was a breach in the cable and the electricity kept flowing, to the point my traps were coming up with melted rocks like lava. Also , the conchs in that particular area started growing without tails , very strange phenomenon.

    • Nonsense!
      And electrical fault that could liquefy a rock will trip a breaker long before the rock gets warm to the touch.

      If cables are that “dangerous” should the one’s that currently feed the Island be removed?
      The Chappaquiddick cable?

  16. As soon as there’s a break in the cable a short circuit is created. The redundant breakers on either end kick in. Melted rocks from the electric cables? The power in these cables isn’t enough to melt rocks. Much more likely you’re pulling up the remains of rocks struck by lightning or the remains of volcanic action from the mid-atlantic ridge.. Maybe thousands or millions of years ago.
    I read the report you linked to. There was an effect but they very clearly stated that there was no statistically noted behavior beyond what could be accounted for with humans creating the artificial environment of the fenced in area. They also noted that very clearly the lobsters were crossing over and back over the buried cable. The presence of humans harvesting ocean life effected the living organisms much more than these cables.
    Significantly effected is sort of relative. Fishing effects these organisms much more than the cables.

  17. All one needs to do is Google ‘EMF’ and see what a huge debate there is about it. If you look at the empirical data, the jury is still out on how much EMF it takes to be a positive factor in DNA damage, but there is no controversy that EMF can create significant health hazards. The level of EMF coming from these cables, underwater, are extremely high. I think people ( Chris Mara)should do a little bit more research before he states un-substantiated facts that go against known data.

    • The Long Island Cross Sound cable was installed twenty years ago.
      It carries as much as 330 megawatts.
      There is twenty years of data.

      “The level of EMF coming from these cables, underwater, are extremely high.”
      What are the units? At what point do they impact DNA?
      Does water impact the transmission of EMF?

      Do the existing cables to the Island radiate too much EMF? Should they be removed?

      I think people (Wesley Nagy) should do some research before he states un-substantiated “facts”.

  18. Wesley, please post actual data regarding EMF. Please find information from MIT or Georgia Tech.

  19. Who will be the first Islanders to offer wind farm tours?
    Will they make more money than fishing?

      • During construction a 1500 foot perimeter may be enforced around each structure.
        The actual enforcement areas will be published in the the local Notice to Mariners.
        Just imagine the majesty of being able to see the graceful sweep of blades up close…

  20. Ok — I found quite a bit of information about
    this subject.
    My guess is that most people have absolutely no
    idea about anything to do with this “issue”
    So I’ll post some actual studies and
    information about this topic.
    I hope everyone takes the time to educate themselves
    about this.
    https://www.rivm.nl/en/electromagnetic-fields/emf-dailylife

    https://www.ehs.iastate.edu/sites/default/files/uploads/publications/manuals/emf.pdf

    q=what+is+a+uT+in+emf&oq=what+is+a+uT+in+emf&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIICAEQABgWGB4yCAgCEAAYFhgeMg0IAxAAGIYDGIAEGIoFMg0IBBAAGIYDGIAEGIoFMg0IBRAAGIYDGIAEGIoFMgoIBhAAGIAEGKIE0gEJMTAxNTlqMGo0qAIAsAIB&sourceid=chrome&ie=UTF-8

    And then of course there are opinions based on some sort of reality

    The little remaining magnetic field strength decays inverse cubed with distance. Submarine power cables cross countless tidal estuaries, rivers, fjords, bays, and seas around the world where marine life of all kinds continue to migrate, breed, and thrive. The EMF issue is simply not an issue. It is just uneducated fear mongering.
    Kyle Kingman, NJ April 19 2019

  21. Some people seem to think that Google gives out academic degrees and is sufficient enough to pontificate and consider oneself “educated” on any topic at all. Some childhood acute leukemias, for example, associated with EMFs, are skipped over by those here with their Google doctorates, while PFAs which are everywhere but no, never in an island football field, are shunned as poison to the kiddos. If you looked it up on Google and it fits with liberal, fake caring hypocrisy, it must be true. There are people who cannot get MRIs or drive their car under those huge electric transmission and distribution lines because of the physical effects of exposure to EMFs. Even the everyday exposures to EMFs give some people cardiac and dermatological symptoms. Why are people told not to hold their cell phones to their ears, but instead use speaker phone when they can? If the negative effects of EMFs are true for humans, what makes people so arrogant that they think sea life, at least some it, is not impacted by this exposure? Common sense, right? I’m no scientist, but I can’t help but notice the disconnect from the very same people who carry on about the dangers of PFAs who now ignore the dangers of EMFs because it does not fit the uneducated, hypocritical, fake caring, and Google-gleaned narrative.

  22. Come on Don, “The little remaining magnetic field strength decays inverse cubed with distance. Submarine power cables cross countless tidal estuaries, rivers, fjords, bays, and seas around the world where marine life of all kinds continue to migrate, breed, and thrive. The EMF issue is simply not an issue. It is just uneducated fear mongering.” is just science babble. don’t trust it..

  23. Don, nationalistic politics is all about fear.
    If everyone is shaking in their boots they will allow almost anything to occur to fix it. Cue Mussolini, Hitler, Mao, and Putin. Yes, both extreme ends of the political spectrum.

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