Hydroelectric Plant Diagram Hydroelectric plants use water as the source of energy to generate electricity.
Penstocks lead the water into a chamber housing the turbine .
The water is held at a higher elevation than the turbine, so that it can fall with enough force to strike the turbine's blades and cause it to spin. The turbine wheel is attached by a shaft to a system of magnets and wires called a generator . The water returns to the river by passing through a draft tube under the turbine and into the tailrace . Homes and industry use a substantial amount of electricity around the clock. Although less than five percent of Duke Power's electricity is generated at its 31 hydroelectric plants, these plants are still an important energy resource.