Woods Hole - OOI buoys
Self-Powered Autonomous Research Buoy
The SPAR Buoy integrates a utility-scale wave energy conversion design into a small autonomous research buoy. The patent pending closed loop air system is a radial impulse-type turbine. It will power free-floating oceanic or moored data acquisition buoys. The system will also provide power for intelligence gathering buoys designed to operate in subsurface stealth modalities. The buoy platform will serve NAVY, NOAA, USGS, homeland security, and oceanographic researchers. The simple power take-off (PTO) provides persistent, power for autonomous, extended mission C4ISR assets at sea.
The SPAR Buoy's PTO was conceived by John Clark Hanna. Battery charging power is delivered by a simple closed loop, mono-radial air drive designed to operate inside a sealed, water-tight compartment. The up and down motion of waves between the buoy and a lightweight heave plate suspended below the bobbing buoy, are translated into a bi-directional air flow within the sealed system. The design provides high velocity, low pressure air to spin a generator. The closed loop assembly and generator are sealed inside a water-tight compartment called the Power Pod. Placed directly below the Power Pod is a Bellows Pod. The Bellows Pod compartment is allowed to fill with water. Air circulating tubes penetrate through a water-tight bulkhead separating the Bellows Pod from the Power Pod. The generator is sealed inside its own separate watertight housing. Even if the air loop or bladders spring a leak, the generator will remain dry and protected from short circuiting.
The oscillating air flow is developed by opposing, stacked sets of flexible Air Bellows or bladders. These expand and contract simultaneously inside the flooded Bellows Pod. The stacked sets of Air Bellows move in unison with an Actuator Arm that moves up and down by the action of metal Push Rods. The full range of Push Rod movement is only 6 to 8-inches. The rods are connected to four Damping Plates that fold down and lock into place extending outward. The combined assembly of Damping Plates and Push Rods are engineered to have a neutral buoyancy displacement. When fully extended, the Damping Plates will resist both ways against the bobbing motion of the buoy. This resistance will cause the Push Rods to actuate the sets of Air Bellows.
Wave action causes the opposing stacked sets of Air Bellows to expand and collapse at the same time. Air from one set of collapsed Air Bellows enters a port in the PTO at one side while air is simultaneously being sucked back through another port by the expanding set of Air Bellows. This concurrent action creates a pure and balanced oscillating air column. In this system, air flow is substantially different than OWC (Oscillating Water Column) type systems. Half of an OWC cycle draws in ambient air from the atmosphere, resulting in an unbalanced, non-uniform flow. In contrast, the SPAR buoy's simultaneous 'push in' and 'pull out' air movement results in lower air resistance (damping) and higher energy capture than common OWC turbine systems.
To assure survivability and long-term operational reliability, the SPAR Buoy will integrate other renewable energy resources such as photovoltaics. By incorporating two redundant systems, a surplus of energy will be available to continuously charge onboard batteries. Thus, a SPAR Buoy will perform its intended mission well beyond the normal life span of comparable buoys.
In-house proof of concept tests have been successfully completed on the patent pending closed loop design (US 62/708,462). Empirical observations show that the simple PTO is reliable and forceful. Unlike other bi-directional pneumatic systems, this primary drive does not use check valves, sensors, solenoids or levers to keep the drive shaft turning in one direction. The system efficiently maintains a positive energy balance even in low sea states. The circulating air within the closed loop is clean, dry and non-corrosive. There is no marine growth to foul internal components. Full size utility scale applications will use a similar radial impulse turbine design for floating or shore based OWC applications.
Contact us to discuss your mission requirements. John Hanna and Fred Wahl Marine are pooling their knowledge and resources to build the highest quality buoys of any size and classification; not just the small self-powered design as described here. Buoys will be built to the highest standards set by the American Bureau of Shipping and U.S. Coast Guard.
Test stand with an early prototype and Bi-directional air pump Prototype Drive with sealed generator housing
Air Bellows Air Bladder
U.S. Navy Advanced Deployable System buoy in 2007 NOAA Data Buoy
John Hanna inspecting a power buoy, Oregon Iron Works John Hanna inspecting sub-surface buoy, Bolon Island
About John Hanna, (DBA WETGEN): Navy veteran. Coast Guard documented mariner. Former skipper of the research vessel "Ed Ricketts" for California State University's Moss Landing Marine Laboratory. Mr. Hanna has twenty eight years' experience in QA/QC management on multi-million dollar government and private sector projects for structural steel and welding. He was contracted by Ocean Power Technologies as the QC manager for their PB-150 PowerBuoy built in Oregon. WETGEN has been a licensed business in the City of Coos Bay, Oregon since 2010 (No. 9098). WETGEN is registered with Dun & Bradstreet.
About Fred Wahl Marine Construction, Inc: Fred Wahl established his shipbuilding business in 1974. There are two facilities in Reedsport, Oregon. The Bolon Island facility has a 50,000 square foot fabrication and machine shop situated on 38 acres. A full description of their capabilities and services is at www.fredwahlmarine.com.
John Hanna Interview Video
Return to Home Page