1. Review of IEA Wind Task 23 OC3 Project Operated for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy by the Alliance for Sustainable Energy, LLC IEA Wind Task 30 Kick-Off Meeting June 8, 2010 Jason Jonkman, Ph.D. Senior Engineer, NREL

2. IEA Wind Task 30 Kick-Off Meeting 2 National Renewable Energy Laboratory IEA Task 23 Organizational Structure

3. IEA Wind Task 30 Kick-Off Meeting 3 National Renewable Energy Laboratory OWTs are designed using aero-hydro-servo-elastic codes The codes must be verified to assess their accuracy OC3 Background

4. IEA Wind Task 30 Kick-Off Meeting 4 National Renewable Energy Laboratory Discuss modeling strategies Develop suite of benchmark models & simulations Run simulations & process results Compare & discuss results Assess simulation accuracy & reliability Train new analysts how to run codes correctly Investigate capabilities of implemented theories Refine applied analysis methods Identify further R&D needs Activities Objectives OC3 Activities & Objectives The IEA Offshore Code Comparison Collaboration (OC3) is an international forum for OWT dynamics code verification

5. IEA Wind Task 30 Kick-Off Meeting 5 National Renewable Energy Laboratory OC3 Participants & Codes 3Dfloat ADAMS-AeroDyn-HydroDyn ADAMS-AeroDyn-WaveLoads ADCoS-Offshore ADCoS-Offshore-ASAS ANSYS-WaveLoads BHawC Bladed Bladed Multibody DeepC FAST-AeroDyn-HydroDyn FAST-AeroDyn-NASTRAN FLEX5 FLEX5-Poseidon HAWC HAWC2 SESAM SIMPACK-AeroDyn Simo

6. IEA Wind Task 30 Kick-Off Meeting 6 National Renewable Energy Laboratory OC3 Coordination & Meetings E-mail coordination Net-meetings held every 1-2 months Physical meetings held 1-2 times per year IEA Wind Task 23 Website (now public!) Database of model parameters & simulation results

7. IEA Wind Task 30 Kick-Off Meeting 7 National Renewable Energy Laboratory All inputs are predefined: –NREL 5-MW wind turbine, including control system –Variety of support structures –Wind & wave datasets A stepwise procedure is applied: –Load cases selected to test different model features OC3 ran from 2005 to 2009: –Phase I: Monopile + Rigid Foundation –Phase II: Monopile + Flexible Found’tn –Phase III: Tripod –Phase IV: Floating Spar Buoy 3-year follow-on project being initiated: –Phase V: Jacket –Phase VI: Floating semisubmersible Approach Phases OC3 Approach & Phases

8. IEA Wind Task 30 Kick-Off Meeting 8 National Renewable Energy Laboratory Load Cases 1.X – Full-System Eigenanalysis Full-system flexibility Elastic response only Compared natural frequencies & damping ratios 2.X – Rigid Rigid turbine Aerodynamics without hydro: –Steady & turbulent winds Hydrodynamics without aero: –Regular & irregular waves 3.X – Onshore Wind Turbine Flexible tower, drivetrain, & rotor Rigid substructure Aero-servo-elastics without hydro: –Steady & turbulent winds 4.X – Inverted Pendulum Flexible support structure Rigid tower-top Hydro-elastics without aero: –Regular & irregular waves 5.X – Full-System Dynamics Full-system flexibility Full aero-hydro-servo-elastics: –Steady winds with regular waves –Turbulent winds with irregular waves

9. IEA Wind Task 30 Kick-Off Meeting 9 National Renewable Energy Laboratory Output Parameters

10. IEA Wind Task 30 Kick-Off Meeting 10 National Renewable Energy Laboratory Papers & Final Report 1 conference paper per phase published/presented: –Phase I: Torque, 2007 –Phase II: EOW, 2007 –Phase III: AIAA, 2009 –Phase IV: EWEC, 2010 Final report reviewing all phases, including updated results submitted since paper publication Journal article in progress?

11. IEA Wind Task 30 Kick-Off Meeting 11 National Renewable Energy Laboratory OC3 aims to verify OWT dynamics codes Simulations tested a variety of OWT types & model features Code-to-code comparisons have agreed well Differences caused by variations in: –Model fidelity –Aero- & hydrodynamic theory –Model discretization –Numerical problems –User error Task 30 will consider offshore jacket & semisubmersible Verification is critical to advance offshore wind Spar Concept by SWAY Semisubmersible Concept Summary

12. Thank You for Your Attention Operated for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy by the Alliance for Sustainable Energy, LLC Jason Jonkman, Ph.D. +1 (303) 384 – 7026 jason.jonkman@nrel.gov