The Federal Energy Regulatory Commission on Aug. 9 put out for 30 days of public comment a final environmental assessment on the Public Utility District No. 1 of Snohomish County‘s experimental Admiralty Inlet Pilot Tidal Project.
The district has applied for a 10-year license for the project, which would be located in Admiralty Inlet in Puget Sound, near the City of Port Townsend, in Island County, Wash. FERC prepared a final environmental assessment (FEA) in cooperation with the U.S. Department of Energy.
The proposed project would consist of: two 300-kW OpenHydro tidal turbines, each approximately 19.2 feet high and mounted on a triangular subsea base; two approximately 7,000-foot-long, 4-kV trunk cables; an approximately 3.9-foot-long, 5.8-foot-wide, 2.9-foot-high on-shore cable termination vault; 40-foot-long conduits to convey the power transmission core cables, the fiber optic elements, and the low-power elements from the cable termination vault to a cable control building; a 24-foot-wide, 30-foot-long on-shore cable control building housing power and monitoring equipment; and a 7.2-kV step-up transformer located adjacent to the control building; a 10-foot-long, buried 7.2-kV transmission line from the transformer to the Point of Metering and the Point of Common Ownership with the Puget Sound Energy grid. The estimated average annual generation of the project would be 244,000 kilowatt-hours (kWh).
FERC compared the total project cost to the cost of obtaining power from a likely alternative source of power in the region. Its analysis shows that during the first year of operation, the project as proposed would produce power at a cost that is $1,840,307 (about $7,542.24/megawatt hour (MWh)) more than the cost of alternative power.
“Although the cost of power that would be produced at the project is high, building the project, in addition to generating electricity, would collect data to further the development of commercial-scale arrays,” FERC noted. “On the basis of our independent analysis, we conclude that issuing an original license for the project with the staff-recommended measures would not be a major federal action significantly affecting the quality of the human environment.”