What are the potential impacts from electromagnetic fields (EMFs) associated with offshore wind?
Work is underway (1) studying the effects of offshore wind-related electromagnetic fields (EMFs) on marine mammals and other wildlife. Early research by the U.S. Offshore Wind Synthesis of Environmental Effects Research (SEER) (2) project indicates (3) that such effects are minimal: “to date, no impacts interpreted as substantially negative have been observed on electrosensitive or magnetosensitive species after exposure to EMFs from a subsea cable.”
The electromagnetic spectrum.
Source: National Institute of Environmental Health Sciences (4)
Everything that conducts electricity emits EMFs, and offshore wind substations and cables are no exception. Watch this video to get a better understanding of what an EMF is (5). Common household appliances, including TVs, hair dryers and electric drills, can emit EMFs similar to or higher in intensity (6) than those emitted by offshore wind cables. Using a microwave oven can produce EMFs (7) of 100–300 milligauss (mG) at a distance of six inches. The Dominion offshore wind farm located in Virginia (8) reported a maximum EMF strength of 112 mG for its offshore export cable (see table below). As is evident in that table, EMFs diminish rapidly as they move farther away from the source—so burying offshore wind cables under the seafloor as much as possible has the potential to significantly reduce EMF strength. Maintaining exposed cable integrity can also help reduce transmission of EMFs.
Summary of calculated magnetic- and induced electric-field levels for 3.3-ft (1 m) burial depth and peak loading at specified horizontal distances.
Source: BOEM (9)
References
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Hutchison, Z.L., Secor, D.H., and Gill, A.B. (2020, December). The Interaction Between Resource Species and Electromagnetic Fields Associated with Electricity Production by Offshore Wind Farms. St. Andrews Research Repository. https://research-repository.st-andrews.ac.uk/bitstream/handle/10023/21420/Hutchison_2020_tos_interaction_between_CC.pdf?sequence=1&isAllowed=y
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U.S. Department of Energy Office of Energy Efficiency & Renewable Energy. (2023, September 13). U.S. Offshore Wind Synthesis of Environmental Effects Research Project. www.energy.gov/eere/wind/events/us-offshore-wind-synthesis-environmental-effects-research-project
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Tethys Engineering. (2022). Electromagnetic Field Effects on Marine Life. U.S. Offshore Wind Synthesis of Environmental Effects Research. https://tethys.pnnl.gov/sites/default/files/summaries/SEER-Educational-Research-Brief-Electromagnetic-Field-Effects-on-Marine-Life.pdf
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National Institute of Environmental Health Sciences. (2024, March 20). Electric & Magnetic Fields. www.niehs.nih.gov/health/topics/agents/emf
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MinutePhysics. (2024, June 14). Learn about Michael Faraday's and James Clerk Maxwell's discovery of the electromagnetic field and waves [Video]. Encyclopædia Britannica. www.britannica.com/science/electromagnetic-field/images-videos
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U.S. Bureau of Ocean Energy Management. (2023, December). Electromagnetic Fields (EMFs) from Offshore Wind Facilities. www.boem.gov/sites/default/files/documents/renewable-energy/state-activities/BOEM-Electromagnetic-Fields-Offshore-Wind-Facilities_1.pdf
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NV Energy. (2024). Understanding EMF. www.nvenergy.com/safety/understanding-emf
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Dominion Energy. (2024). Coastal Virginia Offshore Wind. www.dominionenergy.com/projects-and-facilities/wind-power-facilities-and-projects/coastal-virginia-offshore-wind
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Dominion Energy. (2021, October 29). Appendix AA: Offshore Electric and Magnetic Field Assessment. U.S. Bureau of Ocean Energy Management. www.boem.gov/sites/default/files/documents/renewable-energy/state-activities/Appendix-AA-Offshore-EMF.pdf
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PNNL Community. (2022, May 24). Triton Talks Webinar Series – Electromagnetic Fields with Molly Grear [Video]. YouTube. www.youtube.com/watch?v=BrZNoBYHCsc