How does a hydroelectric power plant convert energy? As water flows through the channels toward the turbines, it has kinetic energy. This is changed to mechanical energy as the water turns the turbines. Then the mechanical energy of the turbines is changed to electrical energy by the generator. As water flows through the channels toward the turbine, it has kinetic energy. This is changed to potential energy within the turbine. This potential energy is converted to electrical energy by the transformer. As water flows through the channels toward the generator, it has potential energy. This is changed to electric energy as the generator rotates. Some of the electric energy is used to change water's energy into kinetic energy. As water flows through the channels toward the transformer, it has potential energy. This is converted to electrical energy by the transformer, and then the energy is magnified by the generator.