Assessment of the Tanana River

Transcription

1 Assessment of the Tanana River (Nenana, AK) for Hydrokinetic Turbine Operations J. B. Johnson, P. Duvoy, K. Moerlein, A. E. Rosenberger, J. W. Schmid, A. C. Seitz, H. A. Toniolo University of Alaska Fairbanks February 16, 2010

2 Hydrokinetic Energy Technology Underwater turbines convert river kinetic energy into electrical power Turbines are placed in relatively high-velocity river currents Does not require dams or power houses Technology is considered precommercial

3 Hydrokinetic Power The river s Power per unit cross-section: KE = 1/2 ρ w V 3 KE - kinetic energy ρ w - density of water V - current velocity

4 Power Requirements for Turbines Hydrokinetic turbines have a resistance to motion that must be overcome (A) An electric power generation curve that is non-linear with respect to current velocity Tanana Max. (B) - April, 2009 (ice-covered) Tanana Max. (C) - October, 2009 (open water) A B C

5 Hydrokinetic Generation Devices Darius type turbines OpenHydro New Energy: Encurrent Blade type turbines Ocean Renewable Power Company Turbine images used with permission Marine Current Turbine

6 Possible Turbine Deployment Scenario RivGen TGU Power Electronics & Interconnection Components Water Surface River Bank Power Cable RivGen TGU Power Cable Power Electronics & Interconnection Components Elevation View Plan View

7 Other Factors Affecting the Hydrokinetic Resource Debris (video after talk) Ice Frazil ice Ice jams River environment current velocity seasonal variation Turbulence Sediment deposition and erosion Channel stability Fish Mortality & injury Effects on migration within the river

8 Tanana River Test Site (Nenana, AK) Goals: Assess river conditions prior to - and after - installation of a hydrokinetic turbine The river power resource: summer & winter The river environment River debris conditions Fish behavior and mortality

9 Tanana River Test Site Bathymetry and October 2008 Current Current data from Terrasond Bathymetry from ACEP 2 m 0 8 m 2 m/s 0 6 m 9 m 12 m

10 River Morphology Current flow line

11 2-D River Modeling Inputs Model mesh Of the bathymetry Measured bathymetry

12 2-D River Modeling Results Velocity (m/s) Maximum velocity Specific Discharge (m 2 /s) Max. Specific Discharge Power area (W/m 2 ) Figure 4a Figure 4b

13 2-D River Modeling Results Thalweg

14 Ice Condition Effects Freeze-up Frazil ice formation When water temperature < 0 C Forms ice buildup on all object in water Ice sheet formation Changes in water current velocity and stage Winter ice sheet Constricted channel depth Hanging frazil ice granule curtains Breakup Potential impact and riverbed gouging

15 Frazil Ice Evolution

16 Frazil Deposition

17 Frazil Ice & Ice Sheet Formation Frazil pans Photo courtesy of Fay Hicks, University of Alberta Anchor ice Photo courtesy of Richard Brown, Pacific Northwest National Laboratory Ice sheet freeze-up Frazil granules Photo courtesy of Fay Hicks, University of Alberta Photo courtesy of Fay Hicks, University of Alberta

18 Winter River Measurements Maximum measured winter velocities m/s

19 Hydrokinetic Devices- Potential Impacts Blade strike Rate of contact Sediment disrup5on Shear stress Noise Electromagne5c fields Toxicity

20 Migratory Resident Fish Arctic grayling Burbot

21 Anadromous Coho salmon Chum salmon Chinook salmon

22 Juvenile Salmon Coho salmon Chum salmon Chinook salmon

23 Knowledge Gaps Large scale/longitudinal Movement Lateral and Ver5cal Movement

24 Closing The hydrokinetic resource & optimal site location for hydrokinetic devices are determined by: The water current kinetic energy density River morphology and dynamics Probability of debris impact Water turbulence Ice conditions Acceptance of hydrokinetic turbines will depend on: Technical and economic feasibility Impact on the riverine environment Stakeholder acceptance (regulators, communities, river resource users, public perception of benefit)