Can Gravity be Harnessed for Electric Energy?

[todo]

How the mechanism of gravity can converted to the electric energy?How much the power result?
Please shared to me, if you have any literature..

 

[banerjeerupak]

You can use gravity in the form of a waterfall. But you can't make a stand alone system without the waterfall. That would mean an endless cycle with only energy output. You are defying the first law of thermodynamics.

 

[Redbelly98]

How the mechanism of gravity can converted to the electric energy?

Google "hydroelectric power" for information. The simple answer is: falling water causes the turbine to rotate in a generator.

How much the power result?
Please shared to me, if you have any literature..

According to this Wikipedia article, the largest hydroelectric plant currently produces around 20,000 MW. There are also smaller capacity plants.
http://en.wikipedia.org/wiki/Hydroelectricity#Largest_hydro-electric_plants