In the past the use of water as a power source was different to how it is used today. The movement in flowing water was used to turn water mills and other machinery, using the kinetic energy rather than converting it to electrical energy first. Later on steam or water vapour was used so flowing water was not required, but a heat source was.
At present we use the movement and enrgy from natural sources to move a generator crerating electricity. We use water to create electricity in three main ways:
Water may possibly be the fuel of the future for our planet. The idea of using water as a power source is, in principle, a clean and reliable method of power production. Instead of harnessing the kinetic energy in flowing water by running it through a turbine the water itself can be split into its products and these used as fuel.