Alaskan wave and river hydrokinetic energy resource assessment, river energy converter testing and surface debris mitigation performance

Tuesday, 16 December 2014: 8:20 AM
Jerome Johnson1, Jeremy Kasper1, Jack Schmid1, Paul Duvoy1, Thomas M Ravens2, Ned Hansen3 and Adeline Montlaur4, (1)University of Alaska Fairbanks, Fairbanks, AK, United States, (2)University of Alaska Anchorage, Civil Enegineering, Anchorage, AK, United States, (3)Oceana Energy Company, Washington, DC, United States, (4)Universitat Polit├Ęcnica de Catalunya-BarcelonaTech, Castelldefels School of Telecommunications and Aerospace Engineering, Barcelona, Spain
The Alaska Hydrokinetic Energy Research Center (AHERC) is conducting a wave energy assessment study at Yakutat, Alaska, and conducting ongoing river technology studies at the Tanana River Tests Site (TRTS) at Nenana, Alaska. In Aug. 2013 an acoustic Doppler current profiler (ADCP) was deployed in 40 m of water off Cannon Beach in Yakutat, AK as part of the Yakutat area wave energy resource assessment. Over the course of the 1.5 year deployment, the ADCP will record area wave and current data in order to verify the area wave energy resource. Preliminary data analysis shows a vigorous wave field with maximum wave heights up to 16 m in Nov. 2013. In addition to the in-situ directional wave data recorded by the ADCP, a SWAN wave climatology spanning the past 20 years is being developed along with a simulation of the wave field for the near shore (5 m<depths<10 m) based on wave statistics provided by the ADCP. Technology studies at the TRTS include performance tests of a research debris diversion platform (RDDP) at protecting a 5 kW New Energy hydrokinetic turbine from river debris flows and to determine the effect of RDDP generated river current turbulence on turbine efficiency. Previous tests have shown that the RDDP effectively sheds debris, however, large debris objects can cause RDDP rotation about its mooring point requiring that a stable attachment between the RDDP and protected floating structure be in place to ensure that debris is diverted away from the protected structure. Performance tests of an Oceana hydrokinetic power turbine will be conducted in late August or early September, 2014 at the TRTS in realistic Alaskan river conditions of current turbulence, high sediment flow and debris. Measurements of river sediment concentration, current velocity and river stage will be made, and current turbulence will be derived. CFD simulations of the RDDP interaction with the river flow will be completed to compare current velocity and turbulence results, depending on the opening angle of the device. Study activities and results will be presented.