What can be done to minimize the impacts of electrolysis from the cable?



Electrolysis can result from improper or damaged DC lines or single-phase AC cables.  However, the type of cable MAV will use has effectively zero chance of producing electrolysis. Our cable has three phase conductors next to each other with an electrical shield, and is mechanically protected by armor.  In addition to this, the induction of current from one run into another requires significant length of close parallel cable placement. Therefore, MAV should not impact any existing electrolysis issues.

Electro-magnetic frequencies

There are many cables along the coast, often in lobster hotspots like Rockland-Vinalhaven, and no effects on lobstering have been documented. The electrical current passing through the subsea cable will produce an electromagnetic field. However, the cable is encased in conductive sheathing (armoring), which blocks electromagnetic field radiation from entering the surrounding environment. The international scientific body of research related to EMF effects is clear—cables do not pose a threat to marine life.

The U.S. Bureau of Ocean Energy Management (BOEM) has evaluated effects of EMF from power cables by conducting in-situ studies of powered and unpowered cables using SCUBA and ROV surveys (Love, et al. 2015, 2016). Results from three years of surveys included:

  1. “Researchers did not observe any significant differences in the fish communities living around energized and unenergized cables and natural habitats;
  2. They found no compelling evidence that the EMF produced by the energized power cables in this study were either attracting or repelling fish or macro invertebrates;
  3. EMF strength dissipated relatively quickly with distance from the cable and approached background levels at about one meter from the cable; and
  4. Cable burial would not appear necessary strictly for biological reasons” (Renewable Energy in situ Power Cable Observation Final Report, BOEM, 2016).