Hydropower, or hydroenergy, is a form of renewable energy that uses the water stored in dams, as well as flowing in rivers to create electricity in hydropower plants. The falling water rotates blades of a turbine, which then spins a generator that converts the mechanical energy of the spinning turbine into electrical energy. Hydroelectric power is a significant component of electricity production worldwide.
People have used moving water to help them in their work throughout history, and modern people make great use of moving water to produce electricity. No doubt, Jack the Caveman stuck some sturdy leaves on a pole and put it in a moving stream. The water would spin the pole that crushed grain to make their delicious, low-fat prehistoric bran muffins. For many centuries, water power was used to drive mills to grind grain into flour. People have used moving water to help them in their work throughout history, and modern people make great use of moving water to produce electricity.
Hydroelectric power for the Nation
Although most energy in the United States is produced by fossil-fuel and nuclear power plants, hydroelectricity is still important to the Nation. Nowadays, huge power generators are placed inside dams. Water flowing through the dams spin turbine blades (made from metal instead of leaves) which are connected to generators. Power is produced and is sent to homes and businesses.
World Distribution of Hydropower
- Hydropower is the most important and widely-used renewable source of energy.
- Hydropower represents about 17% (International Energy Agency) of total electricity production.
- China is the largest producer of hydroelectricity, followed by Canada, Brazil, and the United States (Source: Energy Information Administration).
- Approximately two-thirds of the economically feasible potential remains to be developed. Untapped hydro resources are still abundant in Latin America, Central Africa, India and China.
Producing electricity using hydroelectric power has some advantages over other power-producing methods. Let’s do a quick comparison:
Advantages to Hydroelectric Power
- Fuel is not burned so there is minimal pollution
- Water to run the power plant is provided free by nature
- Hydropower plays a major role in reducing greenhouse gas emissions
- Relatively low operations and maintenance costs
- The technology is reliable and proven over time
- It’s renewable – rainfall renews the water in the reservoir, so the fuel is almost always there
Read an expanded list of advantages of hydroelectric power from the Top World Conference on Sustainable Development conference, Johannesburg, South Africa (2002)
Disadvantages to power plants that use coal, oil, and gas fuel
- They use up valuable and limited natural resources
- They can produce a lot of pollution
- Companies must dig up the Earth or drill wells to get the coal, oil, and gas
- For nuclear power plants there are waste-disposal problems
Hydroelectric power is not perfect, though, and does have some disadvantages
- High investment costs
- Hydrology dependent (precipitation)
- In some cases, inundation of land and wildlife habitat
- In some cases, loss or modification of fish habitat
- Fish entrainment or passage restriction
- In some cases, changes in reservoir and stream water quality
- In some cases, displacement of local populations
