Answer:
Gravitational potential energy
Step-by-step explanation:
Hydroelectric dams are the power plants which generates electricity by using the energy of falling water from a great height.
A the water is stored in big reservoirs and at a great height, it contain lot of potential energy due to the height. As it falls downwards, the potential energy is converted into kinetic energy of the water. this kinetic energy of the falling water is used to run the turbine, and then the electric energy is generated.
So, in hydroelectric power stations, the potential energy of water is converted into the electric energy.