Current Status ofPhase VI Floating Design
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 30Kick-Off Meeting
June 8, 2010
Jason Jonkman, Ph.D.Senior Engineer, NREL
IEA Wind Task 30 Kick-Off Meeting 2 National Renewable Energy Laboratory
• TLP & semi-submersible were both suggested candidates for Phase VI
• More interest in semi-submersible b/c:– Greater system motions & couplings– Importance of hydrodynamic radiation &
diffraction– Catenary moorings
• Principle Power Inc. (PPI) has kindly agreed to design a semi-submersible, based on the WindFloat, & make it available to Task 30 participants Spar Concept by SWAY
Phase VI Floater Concept
IEA Wind Task 30 Kick-Off Meeting 3 National Renewable Energy Laboratory
• WindFloat by PPI, USA
• Designed to support existing WTs:– Modifications only to tower & controller
• Pitch & roll restoring through waterplane area & fixed water ballast
• Tower mounted on one column
• Active ballast system maintains zero-mean pitch angle
• Heave plates improve natural response periods & damping
Spar Concept by SWAY
WindFloat Key Design Features
WindFloat (Image: D. Roddier, PPI)
IEA Wind Task 30 Kick-Off Meeting 4 National Renewable Energy Laboratory
• Tower would be moved to center:– Simplify system’s asymmetry– Avoid issues associated with shift in origin
• Heave plates would be eliminated by compensating with larger columns:– Heave plates require empirically derived
drag– Heave plate IP protected by PPI
• However, design iteration revealed:– Tower in center requires a lot of extra
support structure– Columns would have to be unreasonably
large to achieve desired response periods Spar Concept by SWAY
Original Design Plan by PPI
Semi-Submersible Concept(Image: D. Roddier, PPI)
IEA Wind Task 30 Kick-Off Meeting 5 National Renewable Energy Laboratory
• Keep tower on one column
• Keep heave plates:– PPI will supply suitable drag properties
• Platform will support NREL 5-MW WT
• Aiming for response periods similar to that of OC3-Hywind spar buoy
• Scaled system will be tested in a wave tank within DeepCWind project:– Data will become available for model validation
• Design status:– Design iteration in progress– Developing specifications report– Expected completion in Summer, 2010
Spar Concept by SWAY
Current Design Plan by PPI
Semi-Submersible Concept(Image: D. Roddier, PPI)
IEA Wind Task 30 Kick-Off Meeting 6 National Renewable Energy Laboratory
Spar Concept by SWAY
Preliminary Design Details
Parameter Value Unit
Column diameter 9.7 m
Length of heave plate 13.7 m
Column center to center 46.0 m
Operating draft 16.8 m
Airgap 10.0 m
Pontoon diameter 2.1 m
Bracing diameter 1.5 m
Displacement 4552 tonnes
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 – [email protected]