US Patent 8102071 River and tidal power harvester

An energy module comprising an energy absorber; and a mooring system, comprising a wing-shaped polymer shell attached to the energy absorber, the wing-shaped polymer shell designed to utilize the force of a passing current to create a downward force and thereby reduce any upward motion in the energy module; and a mooring cable housed inside the wing-shaped polymer shell and anchored to maintain the energy module in a fore and aft and a side-to-side position to provide stability, and to negate a rotational force on the energy module.