Inventor, John Hanna, introduces a breakthrough in wave energy conversion: the Hanna Turbine known as a WETGEN (Wave Energy Turbine GENerator), U.S. Patent No. 8,358,026 and the Hanna MultiDrive, a mechanical, direct-drive power take-off (PTO), U.S. Patent No. 8,745,981. Both devices harvest energy from ocean waves by means of the OWC (Oscillating Water Column) principle. OWC technologies are the most mature and well-studied wave conversion systems in the industry. Oregon State University (OSU) built a small working Hanna Turbine. The device was tested with a bi-directional air flow. Acting as an impartial third-party, the OSU College of Engineering issued a final report that validated the Hanna Turbine in 2014.
The simple and robust Hanna Turbine replaces the pioneering but inefficient Wells Turbine. In contrast to the thirty year old Wells design, the transformative Hanna Turbine uses asymmetrical airfoils with a lower angle of attack. This creates more lift and less drag. The design resists "stall", improves self-starting and can function over a wider bandwidth with higher torque values. It offers lower damping (restriction) to the bi-directional airstream. Unlike the Wells, it drives two generators - doubling the power output. Both generators are easily accessable and operate in a dry environment. The Hanna Turbine is more versatile than the Wells, offering three distinct power take-off designs to meet job-specific applications. It can be scaled up to three meters (9 feet) in diameter. A miniature 15cm (6 inch) diameter model can provide battery charging power for small autonomous research buoys.
Generally, wave energy devices operate in the open ocean. This is true for the Hanna Turbine and the Hanna direct-drive PTO. However, both Hanna designs will also function as shore based installations. They can be built into existing or purpose-built jetties or breakwaters and can be easily connected to the grid. All completed EIR studies for existing shore based OWC installations have resulted in FONSI (Findings of no Significant Impact). Hanna shore based power plants will not interfere with maritime traffic, commercial fishing or recreational activities.
As an alternative to a 'shore based' installation, the Hanna 'ocean based' application can be installed on tethered buoys, the legs of off shore oil rigs, or on floating wind and wave harvesting platforms. Hanna primary drives can also spin water pumps to support desalination plants. Another application can utilize the turbine as a bi-directional PTO for utility-scale pressure differential converters fixed to the seabed in the sublittoral zone.
Most deep water designs are sealed up and their generators are inaccesible at sea. To perform maintenance, the sealed devices must be removed from the water and transported to shore. Buoy-mounted applications of the Hanna PTO's avoid these costly O&R haulouts. Routine maintenance on deep water, buoy-mounted PTO's is possible through weather-tight hatches. No generating components are immersed in water. In the case of seabed-mounted pressure differential converters, the turbine is in a sealed module that allows a quick and easy replacement of the Hanna Primary Drive and generator.
To underscore the remarkable versatility of the WETGEN design, the turbine can be easily modified for use as a tidal energy converter. To view a tidal demonstration video, click HERE. Whether applied for wave energy or tidal energy, no other turbine can serve both of these renewable energy sectors!
Videos of the Hanna Turbine can be viewed on the WETGEN You Tube channel. For a more detailed description of the Hanna MultiDrive power take-off, click HERE. Additional information is posted on John Hanna's LinkedIn page or simply Google WETGEN.
To assure the responsible development and successful commercialization of both technologies, the inventor seeks to assign ownership of the patents to an established manufacturer or qualified wave energy developer. For more details and to read the "Forward Looking Statement" click HERE.