Hydropower is a form of renewable energy that derives power from the kinetic energy of moving water. In hydroelectric power plants, water passing through gates in a dam is directed through turbine generators that create electricity on a commercial scale. Let's take a closer look at how this process works.
Water is trapped and stored in the reservoir behind the dam. The flow of water is controlled by the opening and closing of the control gate. When the control gate is open, water rushes through the intake into a tunnel known as a penstock. At the end of the penstock is a water turbine that turns as the water comes rushing in. The turbine is connected by a shaft to the generator. As the turbine spins, it rotates the generator.
The mechanical energy that spins the generator is converted into electricity. Within the powerhouse, the transformer converts the electricity to a high voltage current. The electricity is then sent off to power companies through power lines and distributed to customers.
The used water is carried through outflow pipelines and enters the river downstream.