The diagram illustrates the process of hydroelectric dam. Hydroelectric dam was used for power electricity. Electricity is very important things for human life.
The picture depicts the hydroelectric dam process which is used for electricity.Grammar issue
To take advantage of turbine in the river to produce the power for electricity.
it's bad structure in the sentence because it only consists of to-infinitive clause.
Function of intake for taken water from reservoir into penstock.
where's your verb?
While turbine spins in high spin, the generator catches the power of turbine.
hydroelectric dam takes advantage from turbine. The river gives contribution for hydroelectric dam to get the electricity.
I suggest you to read grammar book