Cross Section of a Hydro Power House
Water enters the plant when an intake gate is opened, and moves through the penstock. Gravity and a narrowing scrollcase increase the pressure of the water as it enters the turbine (in this case a Francis-type turbine). Water exits the turbine and is returned to the river. The turbine spins a rotor directly above it, and electricity produced by the interaction of rotor and stator is transmitted through a transformer at the station and thence to the grid.
Image copyright, Hydro Québec
