Tidal energy represents potential for the generation of renewable, emission free, environmentally benign, and cost effective energy from tidal flows. A successful tidal energy demonstration project in Puget Sound, Washington would potentially enable significant commercial development resulting in important benefits for the northwest region and the nation. Public Utility District No. 1 of Snohomish County (the District) began studying the Admiralty Inlet Pilot Tidal Project (Project) in 2006. This Project promoted the goals set forth by the United States Department of Energy’s (DOE) Wind and Hydropower Technologies Program for advancing the commercial viability, cost-competitiveness, and market acceptance of marine hydrokinetic systems.
The Project purpose was to license, permit and install a grid connected deep-water tidal array to be used as a platform to gather operational and environmental data. The data could then be used to better inform the viability of commercial tidal energy generation from technical, economic, social, and environmental standpoints. This data would serve as a critical step towards the responsible advancement of commercial scale tidal energy in the United States and around the world. Not only would this information impact future tidal energy development, it could also aid in the advancement of other alternative energy developments including wave and offshore wind.
Regulatory requirements necessitated extensive collaboration with local, state, and federal agencies on the Project and resulted in issuance of all required permits and authorizations. Outreach to other stakeholders and interested parties increased public awareness and comfort with the relatively new technology being proposed for the Project, an otherwise unexplored alternative energy source in the region.
Design considerations associated with the Project included but were not limited to the transmission cable, cable laying procedures, power conversion, and grid interconnection in addition to a robust environmental monitoring program developed in coordination with scientists and engineers at the University of Washington, NOAA Fisheries, and other resource agencies. All of the designs developed for the Project under this award can be adapted and applied to future marine hydrokinetic projects, potentially lowering costs, increasing efficiency and creating job opportunities in a growing field.
In late 2014, the District discontinued the Project activities due to escalating costs, and subsequently terminated the DOE award in early 2015. Consequently, remaining tasks including final engineering design, deployment, operation, and monitoring will not be completed. This report discusses the results and accomplishments achieved under the award. The original scope of this award included the following five tasks: Task-1 Regulatory Compliance, Systems Engineering Design and Vendor Selection; Task-2 Final Design, Equipment Procurement and Cable Lay/Power Control Building Construction; Task-3 Go/No-Go Decision in coordination with DOE; Task-4 Turbine Deployment and Electrical Connection; Task-5 Project Operation, Evaluation and Removal. The District collaborated extensively with project stakeholders to complete Task 1 and its subtasks. The remaining tasks had not been reviewed under NEPA at the time of award termination, and had not commenced. Completion of Task 1 above brought the project through all necessary requirements to begin procuring equipment and executing construction agreements in support of deployment of the turbines in Admiralty Inlet.