What sort of hydro energy does a dam use?
A dam builds potential energy by raising the water level. This is converted to kinetic energy by letting the water fall or by releasing it under pressure from the bottom. The high velocity water strikes the blades of a turbine, transferring its kinetic energy to the wheel. The turning wheel rotates a coil of wires against the force of a magnetic field, converting the motion to electrical energy. Tidal generators do the same kind of thing but with huge amounts of slow moving water while wave generators take the mechanical movement of the rise and fall of the waves (since the water doesn’t move out of the area) and a lever arm moves the coil in the magnetic field.
