Description of an intermediate scale tidal energy test site in Great Bay Estuary, NH, with examples of technology deployments

TitleDescription of an intermediate scale tidal energy test site in Great Bay Estuary, NH, with examples of technology deployments
Publication TypeConference Proceedings
Year2014
AuthorsWosnick, M, Rowell, M, Dewhurst, T, Lyon, V, Lippmann, T, Baldwin, K, Swift, R
Conference NameIEEE Oceans '14
Pagination1-7
Conference DatesSeptember 14-19
PublisherMarine Technology Society
Conference LocationSt. Johns, Newfoundland, CA
Keywordsfield deployment, marine hydrokinetic turbines, scale model testing, test site, tidal energy

The Center for Ocean Renewable Energy (CORE) at the University of New Hampshire (UNH) operates a sheltered, intermediate scale (“nursery”) tidal energy test site suited for Marine Hydrokinetic (MHK) turbines up to 4 m (13 ft) in diameter at General Sullivan Bridge in Great Bay Estuary, NH. The UNH-CORE Tidal Energy Test Site is located in a constricted area, and has the fastest tidal current velocities in the estuary with maximum currents at over 5 knots (2.6 m/s), and typically greater than 4 knots (2.1 m/s). The test site has a nominal depth of 10 m, a flat bottom, easy access from two local UNH marine facilities and nearby marinas, and hence it is a cost-effective site for the testing of tidal energy conversion devices. An 11 m x 3 m test platform has been used for MHK turbines up to 1.5 m diameter since 2008, and a larger 20 m x 10 m test platform with a modular turbine deployment system was designed to accommodate larger turbines up to 4 m in diameter. A 4 m diameter axial turbine corresponds approximately to a 1:5 scale model of a utility-scale MHK turbine rated at 1 MWel (based on a full-scale diameter of 20 m, a tidal energy resource of 2.5 m/s and a water-to-wire conversion efficiency of 0.4). A number of MHK turbines have been deployed and evaluated at this test site, including cross-flow turbines with helical blades (Gorlov Helical Turbines), and more recently, an axial Mixer-Ejector Hydrokinetic Turbine designed by FloDesign Inc. under a US Department of Energy (DoE) SBIR phase 2 project. The UNH-CORE Tidal Energy Test Site is well suited to support open-water MHK testing through DoE Technology Readiness Levels (TRLs) 5-6 and 7 (not including grid connection).