This project seeks to advance large offshore vertical-axis wind turbine (VAWT) rotor technology from concept to lab-scale prototype stage through four major research thrusts:

  1. innovative aeroelastic rotor conceptual design,
  2. deep-water system design and cost analysis,
  3. rotor material and manufacturing strategies, and
  4. subscale rotor prototype design & testing.
VAWTs in deep-water have inherent advantages over HAWTs in deep-water, which is illustrated in the figure. This project aims to capitalize on these advantages for offshore wind cost reductions while addressing the key technical, design, and manufacturing challenges for VAWTs.

VAWTs in deep-water have inherent advantages over HAWTs in deep-water, which is illustrated in the figure. This project aims to capitalize on these advantages for offshore wind cost reductions while addressing the key technical, design, and manufacturing challenges for VAWTs.

The overarching project objective is to investigate the feasibility of the VAWT architecture for very large-scale deployment in the offshore environment. The most critical barrier to offshore wind, its high cost of energy (COE), is specifically targeted with the overall goal of achieving a 20% reduction in COE by applying VAWT rotor technology. We will achieve this goal by

  • developing innovative VAWT rotor designs that enable reliable, cost-effective, and easily manufactured rotors for deep-water offshore machines at the 10–20 MW scale;
  • demonstrating the potential for greater than 20% reduction in COE for a deep-water, floating VAWT system compared to current shallow-water horizontal-axis wind turbine (HAWT) systems;
  • developing manufacturing techniques, certification test methods, and a commercialization plan for offshore VAWT rotors in order to accelerate deployment; and
  • testing, in a wind tunnel and combined wind-wave tank, a proof-of-concept subscale, deep-water floating offshore wind turbine employing a VAWT rotor.
The Sandia design studies for VAWT rotors include an assessment of different rotor architectures, numbers of blades, and different material choices. A few of the configurations are shown here.

The Sandia design studies for VAWT rotors include an assessment of different rotor architectures, numbers of blades, and different material choices. A few of the configurations are shown here.

An initial focus of our research has been VAWT code development and code coupling and design studies for VAWT rotor and floating platform. The figure shows several rotor configurations that we have analyzed. In addition, we have performed structural dynamics and resonance impact analyses to investigate the effect different support structures and number of blades on VAWT vibratory response and vibratory loading, which are key design drivers. Our future work includes plans for detailed system design studies and subscale testing.

For more information, please contact D. Todd Griffith.

Publications

  1. Sutherland, H.J., Berg, D.E., and Ashwill, T.D., “A Retrospective of VAWT Technology,” Sandia National Laboratories Technical Report, SAND2012-0304, January 2012.
  2. Owens, B., Hurtado, J., Barone, M., and Paquette, J., “An Energy Preserving Time Integration Method for Gyric Systems: Development of the Offshore Wind Energy Simulation Toolkit” Proceedings of the European Wind Energy Association Conference & Exhibition. Vienna, Austria, 2013.
  3. Owens, B.C., Hurtado, J.E., Paquette, J., Griffith, D.T., and Barone, M., “Aeroelastic Modeling of Large Offshore Vertical-axis Wind Turbines: Development of the Offshore Wind Energy Simulation Toolkit,” 54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, April 8–11, 2013, Boston, MA, USA, AIAA-2013-1552.
  4. Owens, B.C., Griffith, D.T., and Hurtado, J.E., “Modal Dynamics and Stability of Large Multi-megawatt Deepwater Offshore Vertical-axis Wind Turbines: Initial Support Structure and Rotor Design Impact Studies,” 32nd ASME Wind Energy Symposium, National Harbor, MD, USA, January 2014.
  5. Ragni, D., Simao-Ferreira, C., and Barone, M., “Experimental and Numerical Investigation of an Optimized Airfoil for Vertical Axis Wind Turbines,” 32nd ASME Wind Energy Symposium, National Harbor, MD, USA, January 2014.
  6. Fowler, M.J., Owens, B.C., Goupee, A.J., Hurtado, J.E., Griffith, D.T., and Alves, M., “Hydrodynamic Module Coupling in the Offshore Wind Energy Simulation (OWENS) Toolkit,” Proceedings of the 33rd ASME International Conference on Ocean, Offshore and Arctic Engineering (OMAE2014), June 8–13, 2014, San Francisco, California, USA, Paper OMAE2014-24175.
  7. Owens, B.C., and Griffith, D.T., “Aeroelastic Stability Investigations of Large-scale Vertical Axis Wind Turbines,” Journal of Physics Conference Series, Science of Making Torque from Wind Conference, June 18–20, 2014, Lyngby, Denmark.
  8. Fowler, M., Bull, D., and Goupee, A, “A Comparison of Platform Options for Deep-water Floating Offshore Vertical Axis Wind Turbines: An Initial Study,” Sandia National Laboratories Technical Report, SAND2014-16800, August 2014.