Air Force Researchers Capture Wave Energy With 99% Efficiency??

The researchers used a cycloidal turbine, a lift-based energy converter, to grab the energy of a simulated deep-ocean wave. It can change direction almost instantly, and its structure is similar to that of a Voith Schneider propeller, which is used to power tugboats.
It involves a main power shaft and a few hydrofoils whose angle of attack can be adjusted to meet the wave. The main shaft is aligned parallel with the wave crests, according to a paper describing the system presented at an American Society of Mechanical Engineers conference.
The research is part of a National Science Foundation-funded project to build the world’s first free-floating submerged wave energy converter. In a series of experiments, the system was able to convert 95 percent of an incoming wave’s energy into mechanical energy, driving the shaft. The rest of the energy was lost to harmonic waves. But after some tweaks, the Air Force team, led by Dr. Stefan Siegel, was able to improve the energy conversion rate to 99 percent. The work was performed in a small tank, a 1:1300 scale version of the system’s size in the ocean.