Roughly 70 percent of the earth’s surface is covered in water. Water’s natural movement is strong and consistent, making it a perfect source for clean, renewable energy. But with fossil fuels at the focus of the energy debate, it’s not often we hear about hydropower. Find out more about one of the oldest forms of power below.
- How long has hydropower been around, and how does it work?
Running water has long provided power to humans. The Greeks used water wheels to grind wheat over 2000 years ago, according to the U.S. Department of Energy. Since then, there have been a handful of different methods developed for harvesting water’s power. Hydropower has been used in the United States since the 1800s and the Francis Turbine, the most commonly-used water turbine used today, was invented in 1849. In 1879, the largest hydropower facility of the time was created at Niagara Falls, and by 1881, scientists harnessed the falls to power the streetlights in the town. Since then, hydropower has continued to grow.
Today, large dams and other facilities produce electricity by harnessing the kinetic energy of water movement. As water flows, it pushes turbines that are attached to a generator. As the turbines move, the generator converts the movement of the turbine into electricity that can be used to power homes and businesses.
- How popular is hydropower?
Hydropower accounts for roughly 7 percent of the United States’ electricity generation, according to the United States Energy Information Administration. Hydroelectricity accounts for 44 percent of U.S. renewable energy, making it the most popular form of renewable energy used in the country. Worldwide, hydropower supplies a fifth of the world’s electricity and is especially popular in China, Canada, Brazil, the United States and Russia. In Latin America, 65 percent or more of their electricity is generated through hydropower.
In the United States, hydropower is especially popular in the Pacific Northwest. In fact, 70 percent of the electricity produced in Washington state comes from hydropower facilities, according to National Geographic.
- What are some of the pros and cons of hydroelectricity?
As with all forms of energy, hydroelectricity has positives and negatives. Positives include the fact that once constructed, a dam or other hydroelectric facility have a never-ending, strong supply of energy. Dams especially can be used to create electricity on-demand. Hydroelectricity is also one of a handful of clean energy sources that do not produce harmful byproducts in the same way that burning coals or other fossil fuels does. Additionally, the reservoirs created by dams can create opportunities for boating and other activities that would be difficult or impossible otherwise.
However, hydroelectricity is not perfect. The large-scale construction required to build a dam or water power facility often displaces people and animals living in the area and makes the watershed more susceptible to flooding. Also, dams create a huge obstacle for fish, especially salmon, who swim upstream to reproduce. Although dams can minimize the impacts they have on the environment by building in features to make the trip easier on fish, the general scientific consensus is that dams and hydropower facilities are not good for fish and other marine life. Because dams disrupt these natural environments, they can also cause changes in water chemistry that can have adverse impacts.
- What does the future of hydroelectricity look like?
History shows that hydropower can go a long way in transforming economies. For example, Brazil’s investment in hydropower allowed them to reduce their dependence on imported fossil fuels, which reduced the cost of electricity and contributed to massive growth in the nation’s economic status, according to the International Hydropower Association.
Hydropower remains popular in developing nations across Africa, Asia and South America, but is falling out of favor in Southeast Asia due to environmental, economic and social concerns. Despite the popularity of hydropower as a renewable energy source, there are concerns worldwide over the long-term reliability and viability of hydropower projects. Some believe that global warming is and will continue to change rainfall patterns, making dams and turbines less predictable and reliable, according to Slate.
Investment in hydropower facility has remained flat over the past few years, while investments in solar and wind energy projects have steadily increased, according to Circle of Blue, a research organization focused on water and other resources. This shift signals that wind power could overtake hydropower as the leading renewable energy source within the next few years.