Hydropower
Hydropower is a term that simply refers to the energy in water, either the kinetic energy of moving water or the potential energy of water stored in a place where there is the possibility for that water to flow downhill, thus converting the potential energy of the stored water into kinetic energy in the moving water.
Hydropower has been used over the years to run mills.
Hydroelectricity
Hydro power is used all over the world to generate electricity from moving water. Water flows out of a dam through pipes to operate turbines which generate electricity. What happens is that the potential energy in the stored water is converted into kinetic energy in the falling water and when it flows through a turbine this energy is extracted and used to generate electrity.
Generating electricity from flowing water is a renewable energy source and it produces no dangerous climate change gases.
However it is thought that a new dam which floods huge areas of vegetation will produce large amounts of co2 from the flooded organic matter.
 Aswan Dam |
 Hydroelectric dam |