Abstract
At the request of TRC Environmental Corporation (TRC), on behalf of US Wind Inc. (US Wind), Exponent, Inc. (Exponent) calculated the alternating current magnetic fields associated with the operation of the Maryland Offshore Wind Project (the Project), an offshore wind energy project of up to approximately 2,000 megawatts of nameplate capacity within Lease Area OCS-A 0490. Electricity generated by offshore wind turbine generators (WTG) is proposed to be carried on submarine cables to up to four Offshore Substations. Offshore submarine Export Cables will transmit the power to a landfall location at the 3R’s Beach in the Delaware Seashore State Park and then through Indian River Bay to the point of interconnection (POI) with the Delaware electric grid adjacent to the existing Indian River Generating Station. The onshore transmission lines between Indian River Bay and the POI will be installed underground in two double-circuit duct banks. This report summarizes the magnetic fields associated with the operation of the terrestrial duct banks. Magnetic-field levels were calculated for currents projected for long-term average and short-term peak electricity generation (i.e., average and peak load) for a configuration of the proposed onshore cables representative of that to be installed in the two underground duct banks between Indian River Bay and the POI. Magnetic-field calculations were performed for an optimized arrangement of phase conductors to minimize the magnetic-field levels generated by the duct bank, a method discussed by the World Health Organization for reducing magnetic field levels. 1 The magnetic-field levels associated with the operation of the Project’s onshore cables in the modeled duct bank configuration at both average and peak load were calculated to be far below the limits developed by the International Committee on Electromagnetic Safety and the International Commission on Non-Ionizing Radiation Protection,2 which were designed to protect the health and safety of the general public and workers.