Debunking Claims in Hydrokinetics

A reader asked me to comment on the validity of the Wave Roller, a device seen here for extracting the energy from ocean waves.  It’s described by its proponents thus:

The back and forth movement of water driven by wave surge puts the WaveRoller panel into motion. To maximize the energy that the WaveRoller panel can absorb from the waves, the device is installed underwater at depths of approximately 8 – 20 meters, where the wave surge is most powerful. A single panel absorbs 1.5-2 MW of power from the wave surge. The panel spans essentially the entire depth of the water column from the seabed up to the water surface level.

Analyzing this claim requires understanding ocean waves, at least at a basic level.  Here’s something I took from a text for K – 12 science teachers (full text linked above):

Waves in Motion

1. Waves transfer energy through ocean waters without significant horizontal transport of the water itself.

2. A side view of the ocean surface with a wave moving from left to right would show water particles near the surface moving in clockwise circles called orbits. If the wave moves from right to left the orbits are counterclockwise.

3. The diameter of the orbits of the water particles at the surface is equal to the wave height.

4. The diameter of the orbits of the water particles gradually decreases with increasing depth below the surface until orbital motion ceases at a depth of one-half the wavelength.

In essence, an ocean wave imparts no energy to the water running deep beneath it, and thus these claims are fraudulent.

Perhaps an earlier clue lay in the claim, “A single panel absorbs 1.5-2 MW of power from the wave surge.” If there were any truth here, which there isn’t, this would have been expressed as energy, not power.  And wouldn’t it have depended on the size of the wave?