The current design is an improvement of a 1998 patent issued in the U.S., No. 5,808,368. A second U.S. Patent was issued April 26, 2011 — 7,930,885. A U.K. patent, No. GB2467663, was issued on May 16, 2012 and encompasses several improvements.
Top of verticle arm visible at low tide on a very calm day.
The biggest considerations for ocean wave energy devices are capital costs and survivability. Efficiency of capture is far less important, given that the source of the energy is free. Generating the power in the water means inventing entirely new mechanisms which must be maintained in a difficult environment. Generating the power on shore vastly simplifies the maintenance aspects.
Most devices now under development are far more costly and vulnerable to storm damage. The advantage of moving the energy to shore via steel cable is to be able to use conventional pumping or generation technology in a locale where it can be easily maintained. Virtually none of the many designs now being pursued use this approach.