Hydroelectric energy is renewable. This means that we cannot use up. However, there’s only a limited number of suitable reservoirs where hydroelectric power plants can be built and even less places where such projects are profitable.
Generating electricity with hydro energy is not polluting itself. The only pollution occurs during the construction of these massive power plants.
Hydroelectricity is very reliable energy. There are very little fluctuations in terms of the electric power that is being by the plants, unless a different output is desired. Countries that have large resources of hydropower use hydroelectricity as a base load energy source. As long as there is water in the magazines electricity can be generated.
As previously mentioned, adjusting water flow and output of electricity is easy. At times where power consumption is low, water flow is reduced and the magazine levels are being conserved for times when the power consumption is high.
Compared to among others fossil fuels and nuclear energy, hydroelectricity is much safer. There is no fuel involved (other than water that is).
Cons of Hydroelectric Power
Environmental damage. Interruptions of natural water flow can have a great impact the river ecosystem and the environment. ...
High upfront capital costs. ...
Might cause conflicts. ...
May lead to droughts. ...
Risk of floods in lower elevations. ...
Carbon dioxide and methane emission.