Hydropower plants are actually based on a rather simple concept -- water flowing through a dam turns a turbine, which turns a generator. Hydro power is the process of changing the kinetic energy of flowing water in a river into electrical power that we can use.
A dam is built where there is a natural lake or big river in a valley. The gravitational potencial energy stored in the water due to height that is converted in kinetic energy is used to turn generators and create energy.
Here are the basic components of a conventional hydropower plant:
The shaft (rod) that connects the turbine and generator
- Dam - Most hydropower plants rely on a dam that holds back water, creating a large reservoir.
- Intake - Gates on the dam open and gravity pulls the water through the penstock, a pipeline that leads to the turbine.
- Turbine - The water hits and turns the large blades of a turbine, which is attached to a generator above it. The most common type of turbine for hydropower plants is the Francis Turbine, which looks like a big disc with curved blades.
- Generators - As the turbine blades turn, so do a series of magnets inside the generator. Giant magnets rotate past copper coils, producing alternating current (AC) by moving electrons.
- Transformer - The transformer inside the powerhouse takes the AC and converts it to higher-voltage current.
- Power lines.
- Outflow - Used water is carried through pipelines, called tailraces, and re-enters the river downstream.
The water in the reservoir is considered stored energy. When the gates open, the water flowing through the penstock becomes kinetic energy because it's in motion.
