Hydropower: Harnessing Water's Energy

Study Notes

Hydropower is the natural force created by water as it moves from areas of high elevation to areas of low elevation, producing kinetic energy.

Hydropower has been used historically to power mills that milled wheat into flour, to power hammers that break and process ore, and in papermaking.

Hydropower is used to produce electricity, with the U.S. using hydroelectric power to produce 7.3% of its total generated electricity and 37% of its total clean energy.

To produce electricity using water, there must be a flow of water and a turbine connected to an electrical generator.
The water cycle provides the flow of water, with water evaporating, condensing, and falling back to Earth as precipitation.
Rivers and streams flow from areas of high elevation to areas of low elevation, collecting into larger bodies of water and eventually penetrating the soil or flowing into the ocean.
Hydroelectric power plants are built on rivers, with dams creating artificial bodies of stored water (reservoirs) to control the flow of water.
Water flows through holes in the dam (penstock), turning a turbine and powering a generator, producing electricity.

Hydropower is a renewable resource, as water is constantly recycled in the water cycle.
It is a clean energy resource, without the use of fossil fuels that pollute the atmosphere and contribute to climate change.
Hydropower is flexible, cost-effective, and can provide a local power source.

Damming of waterways can disrupt local ecosystems, change water temperatures, and affect plant and animal species.
Creating reservoirs can contribute to greenhouse gas emissions and disrupt the natural flow of rivers.
Fish ladders have been invented to mitigate problems with migratory fish.
Damming can affect organisms that rely on higher water levels or specific flows of water.