Now fill the other tank. The higher that you pump the water, the greater is the energy that is produced when it flows down through the generator. Water from a higher tank spins the turbine in the generator faster than water from the lower tank. This produces more energy and lights more bulbs. This exhibit shows how a hydroelectric dam produces electricity.
Water is stored in a lake behind the dam and channeled through turbines at the base of the dam.
The turbines drive giant generators which produce energy that is sent to run your electric appliances in the home and machinery in factories. Electrical energy from a dam undergoes many transformations before it goes into your light bulbs. Heat energy from the sun evaporates ocean water. The heat energy is changed to potential energy when the liquid water is turned into water vapor. The water flows into the dam from the lake and the kinetic energy becomes potential energy again.