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Are offshore wind developments a threat to Cape Cod? Here’s what experts say.

At a community meeting in Barnstable, residents raised concerns about electromagnetic fields emitted from undersea power lines. Experts say those fields are safer than hair dryers and TVs.

Two offshore wind projects in Barnstable have faced public opposition from Cape Codders, who say they’re concerned about the health and environmental impacts of offshore wind developments. Research shows offshore wind is safe and clean.David L. Ryan/Globe Staff

In the Cape town of Barnstable, a growing backlash to offshore wind projects is threatening two clean energy projects that serve as a backbone for Massachusetts’ transition to clean energy.

Two offshore wind projects — Commonwealth Wind and Park City Wind, both in development by the company Avangrid — have faced public opposition from Cape Codders, who say they’re concerned about the cables that connect the wind turbines to the onshore electricity grid. The cables, which would be encased in cement about 50 feet below Barnstable’s shoreline under Dowses and Craigville beaches, would then snake under residential neighborhoods and connect to the regional electricity grid.


At a Barnstable open meeting, one resident raised concerns for “health ... our future and our families” regarding the magnetic fields emitted by underground transmission cables. Others spoke about ecological disasters, as well as traffic and construction disturbances while cables are being placed below ground. Many asked for the energy to be transferred to an industrial onshore site instead of a residential one.

While these concerns extend beyond Cape Cod, experts from the Department of Interior’s Bureau of Ocean Energy Management and the Department of Energy’s Wind Energy Technologies Office say offshore wind energy is not dangerous.

Electromagnetic fields (EMF)

Electromagnetic fields are a combination of electric and magnetic fields of force. Mobile phones, computer screens, and power lines are examples of equipment that generate EMF. Along the electromagnetic spectrum, power lines are extremely low frequency and X-rays are at the other end of the range, with exposure bringing health risks.

Exposure to EMF from power lines has not been connected to cancer, according to the National Institutes of Health National Cancer Institute. Hair dryers and televisions emit similar EMF, and in some cases more intense, than the underwater power cables used in offshore wind projects, according to Lissa Eng, a spokesperson for BOEM.


A spokesperson from the Department of Energy said undersea cables are already widely used to transport energy, particularly to islands including Nantucket and Martha’s Vineyard. EMF from these cables dissipates quickly with distance from the cable, a BOEM study found.

“The best practice for lowering electromagnetic fields is to bury them,” said Ken Kimmell, who serves as vice president of offshore wind development at Avangrid. “The earth acts as a grounding system.”

With the projects slated to land in Barnstable, Avangrid also plans to encase underground cables in concrete, further lowering the intensity of the fields they can emit.

Underground power lines near residential areas

In Barnstable, undersea cables will bring energy from offshore turbines to onshore transmission sites near homes on the Dowses and Craigville beaches. From these sites, energy will enter the regional power grid. Residents pushed back against the location of these transmission sites, saying they were too close to their homes.

According to RealOffshoreWind, a group of academics and community members who research and assess the pros and cons of offshore wind energy developments, the EMF from offshore wind farms is “about the same as a regular power line that you’d see running alongside roads.”

Kimmell noted that high-voltage power lines run both underground and above densely-populated residential areas, including in Boston, and similar transmission lines proposed for the Cape are no different.

“There is no rule of thumb that you don’t put electric cables under residential areas,” Kimmell said. “Electrons that flow in an underground cable from offshore wind are no different from the electrons that flow in the cables from a fossil fuel plant.”


Whales and marine life

Activists opposed to offshore wind have often turned to the protection of whales to make their case. A Department of Energy spokesperson said animals living near offshore wind developments are protected by federal and state agencies, and each offshore wind project must meet requirements set by the National Environmental Policy, Endangered Species, and Marine Mammal Protection acts.

Federal and state agencies, including the DOE, BOEM, US Fish and Wildlife, and the National Oceanic and Atmospheric Administration, also study sustainable development and coexistence between clean energy sources and wildlife.

Offshore wind opponents have pointed to whale deaths in New York and New Jersey as being caused by acoustic surveys for offshore wind development, however, NOAA found no scientific evidence that noise from the surveys “could potentially cause mortality of whales.” On a webpage dedicated to these concerns, NOAA officials wrote, “There are no known links between recent large whale mortalities and ongoing offshore wind surveys.”

For its part, Avangrid has agreed to several whale protection measures, including boat monitors, undersea cameras, and sonar detection, Kimmell said.

“If we’re in the middle of building and we spot a whale, all work stops until the whale swims to wherever it’s swimming,” he said.

Commercial fishing

The federal government studies the impacts of offshore wind projects on commercial fishing. BOEM and offshore wind developers work with the Coast Guard and commercial fisheries to minimize the effects of turbines and spinning turbine blades, according to RealOffshoreWind.


“These wind farms are in federal waters, so there are federal agencies that have to approve these projects before you can do any work,” Kimmell said. “These issues of impacts to whales and the fishing community are front and center of the review.”

Avangrid is spacing turbines one mile apart from each other to make it easy for commercial boats to navigate, he said.

Compromised views

Opponents of wind energy developments often say wind turbines and power lines will detract from sightlines of the ocean.

The windmills off the coast of Barnstable would not be visible from the shoreline.

In New Jersey, the federal government released illustrations of the view of the ocean horizon. The 900-foot windmills would appear to be about an eighth of an inch in size to people gazing out from the beach, looking a bit like tiny white crosses.

As for the beach itself, Kimmell said Barnstable’s Covell’s Beach, which has already had cables installed for the Vineyard Wind project, looks no different, with the exception of two new manhole covers in the parking lot.

Northeast view showing all visible projects, Stone Harbor Beach, New Jersey. US Department of the Interio/US Department of the Interior

Vivi Smilgius can be reached at Follow her @viviraye.