Many of our usual workshop participants were involved in the locally-hosted regional BEST robotics tournament this past weekend, and so I am concluding the review of past design efforts with the Wave Farm, intended to provide inspiration for Senior, Eagle, and Gold Award projects.
For many years, a poster of the “Wave Farm” concept has been displayed on the wall of my shop for students to drawn inspiration and in order to illustrate other principals used in its design. The concept originally came from inspiration provided by the traditional throw-net used by native Hawai’ian fishermen – the Upena. I originally designed the modular configuration for power generation in the late 1990’s, with updates to the design as AutoCAD’s rendering improved. In 2002, I transferred a copy of the source material from Geocities to my original personal blog, and later submitted a copy to the 2006 Popular Science design contest.
Many of my other designs are derived from the potential of this floating power generating and power capture system, the most obvious being the Flying Sub service vehicle which spawned the Propless Submersible design in turn. The Vibrational Power Generator tested for off-grid environmental monitors was originally created to allow the wave farm capacity to convert power from exceptionally short-length waves, where the more recent Solar Seaweed design replaced this with a flexible floating fringe that can provide additional photoelectric generating capacity able to provide piezoelectric capture of short-length wave motion without moving internal components. For off-grid power production, photoelectric systems can integrate the Concentrated Solar design, while hydrogen gas electrolysis production at deep benthic pressures can provide a more efficient method of longer-term energy storage.
“The Upena Wave-Farm was intended to provide a modular, extensible zero emission design to facilitate the production of electrical power and Hydrogen fuel using a hybrid mix of wind, solar, thermal and wave power generation.”
Modular design built around common components, configurable to meet requirements for power generation and suitability to local environmental conditions. Wave power is extracted through angular movement of the flotation modules, pumping oil through hydraulic pistons.
Movement within the grid also produces power through extension and contraction of each boom, moving a fixed magnet inside a coil with each successive wave. A later version of this design used a torsion spring and flexible linkage to allow bi-directional transformation of linear deflection into rotational power generation.
A similar system operates below the flotation unit, acting as a sea anchor to increase platform stability and avoid flipping of the edge units in heavy storms.
Additional power can be extracted by allowing the rise and fall of the system to pump cold water up through the anchor boom to produce power by way of a pyroelectric layer between the cooling fluid and the upper surface, which is covered with photoelectric panels.
Photoelectric panels also cover the smaller float extensions, designed to capture energy from waves shorter than the boom’s length. These rigid panels can continue as originally designed, or may operate together with or be replaced by the flexible floating Solar Seaweed design.
The extensible design allows this system to capture energy from wavelengths up to twice the length of the grid’s span that travel across the grid from any angle, rather than a single lengthwise axis of movement, losing efficiency with transverse wave propagation
Wind energy is extracted by the vertical turbine atop each module, which also increases wave power generation efficiency by providing torque on each host module as it rests within the extended grid network.
Wave farms operating in coastal waters can provide power directly to the grid through tethered cables, while free-floating farms can electrolyze water and produce commercial quantities of hydrogen of oxygen.
Additional modules can be included for housing, station keeping, and other operational requirements to suit local conditions.