Powering Ontario
Hydroelectric power: how it works
Hydroelectric power harnesses the natural energy of water flowing from a higher elevation to a lower one by the pull of the earth's gravity. It is not only a renewable and clean energy source, but it also helps us moderate electricity rates.
Discover how water power works and how Ontario Power Generation harnesses it, to benefit Ontarians.
Hydroelectricity: falling for the power of water
Learn the basics of how water produces electricity and why it's such a great source of power.
Hydroelectric stations
Hydroelectric generating stations are like factories that convert the energy of moving or falling water into electricity.
Water flowing from a higher elevation to a lower one, called a "drop," creates speed and power.
Hydro stations often use the natural drop of a river, such as a waterfall or rapids, as a natural source of water power. Other stations use a dam built across a river to raise the water level to provide the drop. A third type, called 'run-of-river,' has no drop and instead uses just the natural flow of the river and thus minimizing its impact on the surrounding environment.
Ontario Power Generation has stations of all three kinds within our hydroelectric generation portfolio.
Many of Ontario Power Generation's 66 hydro stations are 80+ years old and still producing safe, reliable power.
How hydroelectric stations work
Water collects at the higher level in the forebay, where it enters through the station's intake into a pipe, called a penstock, which channels it down toward the turbine.
The turbine, like a water wheel, turns with the flow and pressure of water from the penstock and as it turns, it spins a generator.
Inside the generator is a rotor with large electromagnets attached to it. As the rotor spins within a coil of copper wires called a stator, this produces the flow of electrons in the stator we know as electricity.
The flow of water, having served its purpose, exits the station through the tailrace where it rejoins the river.
Stay clear, stay safe
Around hydro stations, dams and surrounding waterways.
Recent hydroelectric projects
Explore our recent hydroelectric projects.
Learn more about Ontario Power Generation's Peter Sutherland Senior hydro station project, which added 28 megawatts of renewable, low-cost electrici...
Learn more about Ontario Power Generation's project to expand Ranney Falls Generating Station with a new generating unit and powerhouse.
Learn more about Ontario Power Generation's project to refurbish the historic waterway that helps supply water to the Sir Adam Beck hydro plants.