How Does a Dam Produce Electricity?
Much of the electricity we use is produced by power plants located in huge dams. Such plants, called hydroelectric plants, are run by the force of falling water.
Water collects behind the dam, rushes down through a pipe and pushes against the blades of a water wheel. The blades are connected to a shaft which spins the generator, producing electricity.
Hydroelectric dams are constructed with a special passageway called the penstock, for water. These passages are sloped downward to create a flow of falling water.
Hydroelectric dams need to be constructed on large rivers that have a large drop in elevation. The dam stores water that can then be controlled by engineers to regulate the water flow to produce electricity on demand at a specific rate.
The generator connected to the turbine rotates, changing the mechanical energy to electrical energy. The transformers convert the electricity to usable voltage levels.
The electricity is then sent through the transmission lines to distribution stations. The electricity thus generated is carried over power lines to places where it is needed.
The electricity produced by the giant 726-foot-high Hoover Dam in Arizona can light up an entire city! The use of hydropower is economical, helps conserve our fossil fuels, and is a clean, environmentally friendly source of energy.