Quad-Rotorcraft to Harness High-Altitude Wind Energy

Part of the Green Energy and Technology book series (GREEN)


Wind at higher altitudes is generally stronger and more persistent than near-surface wind. At many locations the atmospheric flows have annual average power densities that by far exceed these of any other renewable energy sources. Capturing this energy potential has been the objective of a pioneering airborne wind energy concept based on a tethered rotorcraft which was invented in Australia in the 1980s. The chapter summarizes early research with a towed generating rotor, wind tunnel tests and a low-altitude atmospheric test vehicle. These tests have confirmed the feasibility of kite-like flight of a craft having twin or quadruple rotors with the rotors simultaneously generating electricity. Using high-altitude wind data statistics for Australia and the USA it is shown that near base-load electrical outputs can be achieved at capacity factors of 70 to 80%. The governing physical relations of the technology are derived from classical helicopter theory leading to the rotor thrusts and the rotors’ limits to power generation. The range of useful tip-speed ratios is presented for the complete range of rotor disk incidence angles. This mathematical model is used to describe the low-altitude operation of a small quad-rotorcraft. The model is suitable to predict the performance of a multi-megawatt machine. The final contribution of the chapter is a dynamic analysis of the system to devise a control strategy for the craft’s power output, pitch, roll and yaw, using purely blade collective pitch action.


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  1. 1.
    Atkinson, J. D. et al.: The Use of Australian Upper Wind Data in the Design of an Electrical Generating Platform. Charles Kolling Research Laboratory Technical Note TN D-17, 1–19 (1979)Google Scholar
  2. 2.
    Bramwell, A. R. S.: Helicopter Dynamics. Edward Arnold (Publishers) Ltd., London, UK (1976)Google Scholar
  3. 3.
    Fletcher, C. A. J., Roberts, B. W.: Electricity generation from jet-stream winds. Journal of Energy 3(4), 241–249 (1979).  https://doi.org/10.2514/3.48003
  4. 4.
    Gessow, A., Crim, A. D.: An extension of lifting rotor theory to cover operation at large angles of attack and high inflow conditions. Technical Report NACA TN-2665, Langley Aeronautical Laboratory, Langley Field, VA, US, Apr 1952. http://naca.central.cranfield.ac.uk/reports/1952/naca-tn-2665.pdf
  5. 5.
    Gessow, A., Myers Jr., G. C.: Aerodynamics of the Helicopter. Macmillan Co., New York, NY (1952)Google Scholar
  6. 6.
    Ho, R. H. S.: Lateral Stability and Control of a Flying Wind Generator. M. E. (Res) Thesis. M.Sc.Thesis, University of Sydney, Nov 1992. http://hdl.handle.net/2123/2609
  7. 7.
    Hoffert, M. I., Caldeira, K., Jain, A. K. et al.: Energy Implications of Future Stabilization of Atmospheric CO2 Content. Nature 395, 881–884 (1998).  https://doi.org/10.1038/27638
  8. 8.
    Jabbarzadeh Khoei, A.: Optimum Twist for Windmill Operation of a Tethered Helicopter. M. E. Studies Thesis. M.Sc.Thesis, University of Sydney, Aug 1993. http://hdl.handle.net/2123/2608
  9. 9.
    Manalis, M. S.: Airborne Windmills and Communication Aerostats. Journal of Aircraft 13(7), 543–544 (1976).  https://doi.org/10.2514/3.58686
  10. 10.
    O’Doherty, R. J., Roberts, B. W.: The Application of U.S. Upper Wind Data in One Design of Tethered Wind Energy Systems. SERI/TR-211-1400, Solar Energy Research Institute, Golden, CO, USA, Feb 1982.  https://doi.org/10.2172/5390948
  11. 11.
    Rancourt, D., Bolduc-Teasdale, F., Demers Bouchard, E., Anderson, M. J., Mavris, D. N.: Design space exploration of gyrocopter-type airborne wind turbines. Wind Energy 19, 895–909 (2016).  https://doi.org/10.1002/we.1873
  12. 12.
    Roberts, B.W.: Quad-Rotorcraft to Harness High AltitudeWind Energy. In: Schmehl, R. (ed.). Book of Abstracts of the International Airborne Wind Energy Conference 2015, pp. 84–85, Delft, The Netherlands, 15–16 June 2015.  https://doi.org/10.4233/uuid:7df59b79-2c6b-4e30-bd58-8454f493bb09. Presentation video recording available from: https://collegerama.tudelft.nl/Mediasite/Play/102d7cb3437542acbf4078bac1e853eb1d
  13. 13.
    Roberts, B. W.: Control System for A Windmill Kite. Australian Patent 2009238195, Apr 2009Google Scholar
  14. 14.
    Roberts, B.W.: Design and Preliminary Performance of the Gyromill Mk2. End of grant report 380, Department of Resources and Energy, Canberra, Australia, Oct 1984. http://nla.gov.au/nla.cat-vn2242481
  15. 15.
    Roberts, B. W.: Private papersGoogle Scholar
  16. 16.
    Roberts, B. W.: Windmill Kite. US Patent 6,781,254, Aug 2004Google Scholar
  17. 17.
    Roberts, B. W., Blackler, J.: Various Systems for Generation of Electricity Using Upper Atmospheric Winds. In: Proceedings of the 2nd Wind Energy Innovation Systems Conference, pp. 67–80, Solar Energy Research Institute, Colorado Springs, CO, USA, 3–5 Dec 1980Google Scholar
  18. 18.
    Roberts, B.W., Shepard, D. H., Caldeira, K., Cannon, M. E., Eccles, D. G., Grenier, A. J., Freidin, J. F.: Harnessing High-Altitude Wind Power. IEEE Transactions on Energy Conversion 22(1), 136–144 (2007).  https://doi.org/10.1109/TEC.2006.889603
  19. 19.
    Sechel, E.: Stability and Control of Airplanes and Helicopters. Academic Press, New York (1964)Google Scholar
  20. 20.
    Strudwicke, C. D.: A Control System for a Power Generating Tethered Rotorcraft. M. E. (Res) Thesis. M.Sc.Thesis, University of Sydney, Nov 1995. http://hdl.handle.net/2123/4993

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© Springer Nature Singapore Pte Ltd. 2018

Authors and Affiliations

  1. 1.Altitude Energy Pty. LtdBrisbaneAustralia

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