Falmouth Contemplating HVDC Converter Electric Station

On June 8, 2022, the Town of Falmouth received plans from ocean wind contractors to install onshore cables through the town to a six-acre 1200-megawatt high voltage direct current converter station. The purpose is to change the direct voltage power from the wind turbines to alternating current so it can go onto the existing electric grid. footnote (#1)

The 1200 megawatt power from the offshore wind project is around twice the power output of the old 680 megawatt Pilgrim nuclear plant. There have been no public meetings, hearings, notifications, or studies since June 2022.

High voltage direct current converter stations are rare in the United States because we use alternating current on the existing electric grid. Ayer, Massachusetts has one HVDC converter station at the Sandy Pond Electric Station, where high voltage direct current is brought from Quebec, Canada, and changed to alternating current for Massachusetts.

In 2007 the Sandy Pond electric substation, Ayer, Massachusetts HVDC converter station had what was called a cascading electrical accident. Three years later a 2010 report concluded: "Had any of the protection systems mis-operated the outcome may have been different." footnote (#2)

What could be a different outcome in September 2021 the Sellindge HVDC converter station in Kent, England had an accident that required 12 fire crews. The center of the plant imploded. The plant linked the power from France to England with the repairs taking two years. The protection systems did not work. footnote (#3)

To put the amount of power in perspective these HVDC converter stations are usually between countries. Falmouth is a residential beach and boating vacation destination with a large retirement community.

HVDC Converter stations create acoustic noise and can generate serious levels of radio-frequency interference. High walls and setbacks could provide noise protection to accommodate the Falmouth noise decibel zoning. In addition, oil from equipment must be prevented from contaminating groundwater in case of a spill. Generally, pressurized foam with its environmental issues is used in firefighting electric fires.

The US electric grid uses SF6 for insulation in circuit breakers, gas-insulated electric substations, and switching units. It is the most potent greenhouse gas known. SF6 can have a major impact on global climate change.

Falmouth depends 100 percent on the Cape Cod aquifer and reservoirs for drinking water. In September 2020 members of the Falmouth Select Board sent a letter to the Massachusetts Army Nation Guard commenting on the proposed gun range environmental hazards of groundwater contamination from copper bullets and gun residue.

In 1982 the Cape Cod aquifer was designated the sole source of drinking water for Cape Cod and any projects on Cape Cod receiving federal funds could be subject to the sole source aquifer review as outlined in the Safe Drinking Act. footnote (#4)

The Bronx, New York has proposed an HVDC converter station in which a children's museum brought up one-quarter mile setbacks, public health threat of exposure to EMF, and electric magnetic fields, that have been linked to clusters of childhood leukemia in various scientific studies. footnote (#5)

Footnotes with links are provided to fact-check

(#1) Page 8 HVDC Converter
https://www.falmouthma.gov/DocumentCenter/View/12338/Mayflower-Forum---Mayflower-Pres-2-06082022

(#2) Sandy Pond HVDC accident:
https://truc.org/wp-content/uploads/2014/08/ma-p3-analysiscascadingevent.pdf

(#3) Sellindge HVDC converter station in Kent, England accident
https://www.mirror.co.uk/news/uk-news/breaking-huge-fire-breaks-out-24987920

(#4) Cape Cod EPA sole source aquifer. December 2021
https://www.epa.gov/newsreleases/epa-announces-sole-source-aquifer-review-process-including-public-participation

(#5) Bronx, New York has proposed an HVDC converter station
https://www.bronxchildrensmuseum.org/single-post/clean-path-new-york-s-proposed-high-voltage-converter-station-poses-environmental-justice-threat