Tidal Energy Exploration in Puget Sound

Transcription

1 Tidal Energy Exploration in Puget Sound

2 Project Objectives Objective is to generate relevant data to better evaluate the technical, economic, and environmental feasibility of tidal energy generation. Project will design, install, operate, maintain and evaluate a two-turbine, temporary, grid connected pilot plant in Admiralty Inlet. Planning for 3-5 years of turbine operation. FERC license will require removal of turbines at end of license term.

3 Voith Verdant Power U.S. Marine Current Turbines - UK Clean Current - Canada Open Hydro - Ireland

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5 Project Overview Tidal Energy Turbines: The project will install two 6-meter diameter Open Center turbines manufactured in Ireland by OpenHydro Ltd. Turbines will be 6 th or 7 th generation design. Turbines have only one moving part and utilize a permanent magnet, direct drive generator. No lubricating oils or greases are utilized. Typical rotor speeds of 6-16 rpm will rotate ~70% of the time.

6 Project Overview Turbine Foundations: Turbine foundations will be manufactured in the U.S. (or Canada if necessitated by the Jones Act) Each foundation will weigh ~300 tons and will secure its turbine to the seabed via gravity only no piling, pinning, or other seabed preparation is required. Foundations are constructed of steel, filled with concrete ballast, and protected from corrosion via sacrificial anodes.

7 Project Overview Turbines will be installed ~1km off of Admiralty Head, Whidbey Island. Each turbine will be connected by its own subsea cable to shore near the Keystone ferry terminal. Each subsea cable will transmit power to shore, transmit data & control signals, and provide shore power for turbine instrumentation. Cables will be laid directly on the seabed -- horizontal directional drilling will be utilized to install cable beneath the shoreline.

8 Project Overview Multiple years of AIS data was gathered to inform consultation with the Coast Guard, Navy, Puget Sound Harbor Safety Committee, American Waterways Operators, and other stakeholders.

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10 Project Overview Shore landing is on privately held land for which the District has established a lease/easements. A residential garage-style structure will be built to house on-shore electrical and controls infrastructure. Puget Sound Energy may upgrade approximately 1500 ft. of distribution line from single phase to three phase to facilitate grid interconnection.

11 Turbine Installation Turbines will be installed utilizing the OpenHydro Installer barge and local tugs. Each turbine will be fitted to its foundation at/near the pier and tow tested by the barge prior to deployment. Potential U.S. ports include Anacortes, Bellingham, or Seattle; however U.S. Customs has rejected our second request for an oceanographic research exemption to the Jones Act.

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13 Turbine Installation Several turbine/cable installation scenarios are currently being evaluated. Highly detailed story boards are developed for each scenario

14 Completed Project

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16 Project Monitoring Fish aggregation at the European Marine Energy Center

17 Project Monitoring Environmental monitoring and O&M. Near-turbine monitoring package design, fabrication, and testing: Annual environmental monitoring activities: Marine Mammal monitoring Benthic monitoring via ROV Acoustic monitoring Near-turbine instrumentation package retrieval and redeployment 2-4x per year

18 Strike Analysis of SRKW Scenario: Curious animal approaches the turbine head first Adult male represents greatest mass, lowest momentum exchange, and greatest force absorbed by tissue Analysis Process: Determine the force from turbine blade concentrated on orca forehead Determine the anatomy (thickness of skin, blubber, bone) and biomechanical properties (force to deform or tear tissue) of orca tissue and bone Engineering model by Sandia National Laboratories Biomechanical analysis by Pacific Northwest National Laboratory Modeled Region of Impact 18

19 Analysis Spacing of blade edges and spacing between blades Numerical models to evaluate movement and force of blades under operating speeds (~1-3m/sec) Model (mesh) of orca body for interaction with turbine blade SRKW skin is very strong, acts to spread force across area (less damage to underlying tissue) Little information about biomechanics of marine mammal tissue, esp. skin Need analogue for skin = synthetic rubber 19 Also examined potential for materials on leading edge of blade to spread force, decrease impact

20 Modeling Inputs and Initial Results Relationship between impact speed and stress/strain: Linear between 1 and 3 m/s, can extrapolate to higher speeds, assuming linear relationship Maximum velocity SRKW and blade impact scenario schematic Comparison of impact forces with speed of turbine blade Maximum stresses/strains calculated: 3250 kpa/73% for turbine impacting stationary body 2365 kpa/93% for SRKW swimming toward turbine Stress well below the yield stress for similar materials: Natural rubber = 10,000 to 30,000 kpa Strain below that known for human skin ( %) Bottom Line: with the available information, using worst case of adult male orca: Tissue changes in elastic region for skin and blubber Damage from impact of blade is minor, equivalent of bruising 20

21 Project Milestones Submitted Final License Application (FLA) to FERC March 1, Receive FERC Pilot Plant License September Award OpenHydro Supply and Installation contract October Ship turbines July Onshore construction, foundation fabrication, and subsea cable lay Late Install turbines on foundations, conduct testing and tow trials September Deploy turbines October/November Commissioning January 2014

22 Questions?