Inexpensive floating horizontal and vertical axis water turbines mounted on bridge and other structures to convert hydrokinetic energy to electric energy

A system for converting hydrokinetic energy in waves, water currents and in tidal flows comprising:

• a. at least one bridge support column, seawall or a sturdy structure disposed in a body of water;
• b. at least one horizontal-axis water turbine (HAWT) that can convert hydrokinetic energy to rotary motion;
• c. a hollow turbine hub that keeps the turbine afloat on the surface of the water and the turbine axis lies perpendicular to the direction of the flowing or moving water;
• d. a vertically slidable rigid assembly consisting of at least one water turbine that turns at least one electric generator at a higher rpm than the water turbine itself through a gearing system;
• further, the electric generator that is:
• i. a low-rpm kind developed for wind turbines;
• ii. a high efficiency kind developed for wind turbines.
• e. each water turbine-comprising a plurality of blades circumferentially spaced around the turbine hub;
• f. a system of cable, pulley and weight anchored to the bridge column or other structures well above the water line for holding up the vertically slidable turbine-generator assembly in claim 1d such that:
• i. the bottom half of the water turbine is submerged in water and the other half is above the water level;
• ii. the top half of the water turbine that is above the water level minimizes the drag on the turbine blades while turning in the air above the water level for maximizing turbine efficiency;
• iii. the electric generator is always held above the water.