Abstract
Ocean tides are a significant, largely untapped, source of renewable energy around the world. Harsh marine conditions, including high hydrodynamic loads, present significant challenges for commercializing technologies that can convert the hydrokinetic energy in tidal currents into electricity. A tidal energy converter (TEC) must be robust enough to safely operate in this energetic and corrosive environment. It will experience a wide range of dynamic loading that can depend on both space and time, including turbulence – from estuary- to blade-scale, tidal phase, and wake effects.
Sandia National Laboratories has partnered with the University of New Hampshire – Atlantic Marine Energy Center, National Renewable Energy Laboratory, and Pacific Northwest National Laboratory to design, manufacture, deploy, and test an open-source axial flow 2.5 m diameter, highly instrumented reference hydrokinetic turbine, referred to as the Open-Source Tidal Energy Converter (OSTEC) test bed. The size of the turbine was chosen to be of a scale relevant to local flow structures, and to be large enough for its performance to be independent of Reynolds number. The device will be deployed at the UNH-AMEC Tidal Energy Test Site at Memorial Bridge in Portsmouth, NH, where its power performance and load-response will be characterized. Experiments will be conducted under the various design and measurement load cases outlined by the International Electrotechnical Commission (IEC) standards for marine energy converters (TC-114).
The project will provide temporally synchronized measurements of power performance, environmental and inflow conditions, and dynamic blade loading. In addition to informing the IEC marine energy standards, the performance, loading and resource data from the testing campaign will be made publicly available. Such extensive data sets currently only exist in the public domain for small scale models of TECs. Almost all studies relating to relevant/field scale TECs are proprietary or limited in nature. This will be one of the first comprehensive, publicly available data sets for a TEC of this scale.
This contribution will focus on the design and testing of the OSTEC. A detailed description of the mechanical design and turbine assemblies, instrumentation, data acquisition, and system integration will be presented, along with the experimental test plan designed to measure, study, catalogue, and publicly archive the various load cases set forth by the IEC marine energy standards.
This work is supported by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) through the Water Power Technologies Office (WPTO). Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. This abstract describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the U.S. Department of Energy or the United States Government.