A previous version of this page described the Hanna Turbine, US utility patent 8,358,026.  The Hanna Turbine is both a wave and tidal energy converter.  The full patent has now been assigned and is owned by HydroWing, a highly qualified tidal energy developer in the United Kingdom.  The new owner and its partners, QED Naval in Scotland and Tocardo in the Netherlands, enjoy a substantial economic and technical advantage because the Hanna Tidal Turbine has no gear box and uses fixed-pitch blades to harness cross-current tidal flows.  Blade pitch mechanisms are unnecessary.  Its large diameter, multiple blade rotors efficiently captures power from the tides.  The simple, adaptive Hanna drive line is key to the turbine's versatility and low O&M cost. 

  The following information describes another Hanna wave energy system that is available for acquisition.



    In-house Proof of Concept testing has been successfully completed for the mono-radial design by Oregon inventor John Clark Hanna.  The new radial power take-off (PTO) is a novel and exquisitely simple wave energy converter.  From the exterior, the method of air intake appears to be self-evident.  But inside the turbine's casement, there is a proprietary method of directing the air.  The full force of the incoming air flows are efficiently harnessed to increase the rotational driving force.

  Unlike common OWC (Oscillating Water Column) impulse turbines, the new Hanna PTO somewhat resembles a Pelton Wheel.  It is a radial, self-rectifying air wheel that does not use valves, sensors or solenoids to help the rotor turn in one direction.  Peripheral collector vanes help develop optimal momentum.  The Hanna design uses a special air-cored, axial flux generator which avoids the magnetic resistance and drag that normally hinders a turbine's forward motion and torque.

  The Hanna Radial Drive is versatile.  It can also operate within a sealed closed loop system. The closed loop system has a balanced air flow in both directions.  Unlike the OWC application, the closed-loop version is never exposed to corrosive salt water mist and the resulting marine slime that coats internal parts.  The closed loop system's output can be scaled and is ideal for subsurface, utility-scale buoys.


  When operated as an OWC-type converter, the design will power shore-based installations, surface buoys and fully submerged buoys that are out of sight from the shore.  The subsurface buoy's excitation force is caused by the fluctuating pressure differentials created by passing waves above the structure and the relatively static pressure at the buoy's lowest point.  To learn more about the proprietary subsurface buoy, contact John Hanna directly.

  For information on another patented wave energy converter, a mechanical direct-drive PTO called the Hanna  MultiDrive click HERE.

To reverse the tide on Climate Change in 2020, the inventor is offering for acquisition both of his wave energy conversion technologies - the Hanna Mono-radial Turbine and the MultiDrive PTO, to an established and qualified entity.