What Makes Hydroelectric Power an Inexhaustible Fuel Source?

Hydroelectric power turns the potential energy of water stored behind a dam into electric energy. Unlike electric energy generation with fossil fuels, hydroelectric power is renewable since the water cycle continually replenishes lakes and rivers at higher elevations.

Function

• Heat from the sun warms the water in the ocean, which evaporates and condenses to form clouds at higher altitudes. Part of this water returns to the land through precipitation. Precipitation feeds rivers, streams and lakes with water which will flow back toward lower elevations and eventually into the sea. By trapping water in streams and rivers with dams, people can take advantage of this cycle to generate electricity.

Features

• Hydroelectric power is renewable and thus inexhaustible because the water cycle continuously returns water to higher elevations and feeds the rivers and streams we use for electricity generation. As long as the sun continues to heat seawater and drive evaporation, the water cycle will continue, and people can use potential energy in the form of water at high elevation for power.

Considerations

• Hydroelectric power may be an inexhaustible resource, but inexhaustible should not be confused with limitless. There are only a limited number of streams and rivers suitable for damming, so there is only so much electricity that can be generated with hydroelectric power. Moreover, if climate change redistributes precipitation or causes glaciers to melt, it could dry up some streams and rivers that currently supply hydroelectric power and force us to seek alternatives.