Many energy sources are used in this day and age but which will be used in the future. Coal, natural gas, and other non renewable energy sources will not always be around to run the Earth. Soon the Earth will have to rely on more efficient energy sources such as the energy of the future, hydro electricity. Hydroelectricity is one of the top used energy sources in the world due to the fact water is basically everywhere. Like coal it is very abundant but coal is very harmful to the environment whereas water won't destroy the environment.
The Hoover dam is the biggest in America.
Hydroelectricity is created by water running through a turbine at very fast speeds, The turbines are usually installed in a dam, where the operators can control the water flow, therein controlling the flow of electricity
The Wilson Dam in Florence, Alabama.
While it costs more to build and keep running, the Hoover Dam produces 4 times the power a typical coal plant does, and can do this endlessly and without polluting, thanks to the fact that it uses water to get energy.