Snohomish County Public Utility District has selected OpenHydro of Ireland to design, build, and install up to three marine turbines at a 1-MW tidal energy pilot plant in Admiralty Inlet, in Puget Sound west of Whidbey Island, Wash.
The pilot project could begin operating in 2011, producing up to 1 MW, enough to serve about 700 homes, the utility said April 14. The tidal devices are to be connected to subsea electric cable linked to transmission lines on Whidbey Island. The turbines are to be positioned outside of the main shipping channel and ferry routes, the utility said.
In the next two years, Snohomish PUD is to focus on finalizing its engineering plans and obtaining approvals from the Federal Energy Regulatory Commission and other state and federal agencies. In addition, the utility said it plans to conduct studies to better assess tidal flows, seabed composition, the presence of fish and marine mammals, cable routes, and interconnection options.
An appropriations bill signed by President Obama included $475,000 to support the utility’s tidal energy projects proposed off Washington’s coast. (HNN 3/20/09)
Although the capacity of the pilot project is listed as 1 MW, Snohomish PUD holds a preliminary permit from FERC to study the feasibility of a 22.5-MW Admiralty Inlet project (No. 12690). It also holds permits from FERC to study four other projects: 6.2-MW Deception Pass (No. 12687), 3.5-MW Guemes Channel (No. 12698), 5.3-MW San Juan Channel (No. 12692), and 8.3-MW Spieden Channel (No. 12689).
During the Admiralty Inlet pilot project, Snohomish PUD is to conduct in-water testing and monitoring to address issues related to tidal turbine performance, cost, and environmental effects. It plans to place up to three horizontal-axis tidal devices on the seabed floor. The units will measure 50 feet in height and can spin either way, depending on the direction of the tides.
The turbines will be manufactured at OpenHydro’s technical design and assembly center in Ireland. The company’s commercial-scale test turbine is operating at the European Marine Energy Center in Scotland. (HNN 10/20/08)
Snohomish PUD is working with several technical partners, including the University of Washington and the Electric Power Research Institute. In 2008, the Department of Energy provided a $1.2 million grant to the utility to support the tidal energy effort in Admiralty Inlet. (HNN 9/18/08)