Why is hydropower used?

Answer 1

I assume what you're actually asking is what makes it more useful than conventional fossil-fueled based electric sources. Hydroeletric plants produce energy by tapping into the kinetic (and at times potential) energy of water. An overly simplified example is this: imagine there is a lake at an elevation of 1000ft. The lake is in an area that rains a lot and keeps the lake full. It rains so much in the lake that there is a river going from the lake that eventually empties out into the ocean. If you put a turbine in that water, the river will push the turbines as it flows. That kinetic energy is then converted to electricity (copper moving through a magnetic field; the explanation of how electric is produced in that manner is beyond the scope of this question), and the electricity is then sold to consumers. One complaint about hydroelectricity is that sometimes it can have a negative effect on the localized environment by upsetting the natural flow and status of the water source it's tapping.

Answer 2

Hydropower or hydroelectric power is used to make electricity for homes and businesses. It is produced by damming water and forcing it through turbines to create steam.