Although solar and wind energy are the most prominent forms of renewable energy generation, hydroelectric power, which uses moving water to generate energy, is one of the oldest. You can date hydroelectric power back at least 2,000 years when the Greeks used the force of water to turn wheels for grinding wheat into flour. Later, in the 1700s, hydroelectric power was popular for pumping and milling and in the early 1900s the process was used to create electricity. By the 1920s, hydroelectric power supplied nearly 40 percent of the electricity in the United States.
While hydroelectric power was once a popular choice for electricity generation, its use has slowly declined over the decades. Now hydroelectric power only makes up about 9 percent of electricity generation in the United States. This has occurred, in part, because of the nation's growing population and increased energy demand. Many also believe hydroelectric dams pose an environmental threat, hindering the development of more hydroelectric projects.
How is hydroelectric power generated?
Like all forms of renewable energy, hydroelectric power transforms the energy from a natural resource into electricity. In this case, the force of water is harnessed to generate clean power. Hydroelectric plants, which are often situated on dams, push water through a series of turbines. As the water forces its way through, the turbines spin and create kinetic energy. Then an attached generator is able to capture the energy and convert it into the electricity.
The environmental impact of hydroelectric power
There are a lot of great perks to using hydroelectric power. It's a consistent electricity source, it uses an abundant natural resource and because no fuels are burned it has negligible air emissions. And although some might worry about pollution in the water source, the generation process is completely clean. Once water has pushed through the turbines, it returns to the body of water below the dam. But still, there are a couple of environmental issues that stand as a barrier to hydroelectric power today.
· Wildlife impacts. A major concern for environmentalists is that hydroelectric power plants are usually situated on dams. While dams are used for a number of other purposes, such as flood control, recreation and agricultural irrigation, they can change the habitats of natural wildlife. In addition to altering ecosystems of plant and aquatic life, hydroelectric turbines can injure or kill fish without proper precautions such as in-take screens to keep aquatic life out.
· Land use. Often times, hydroelectric plants are massive and consume a large amount of land. Not only does this land use disrupt ecosystems, it can cause erosion at river beds and block scenic views.
Considering these environmental factors, installing hydropower has been a strenuous ordeal for decades. With government rules and regulations, it could take years to get approval to build a new hydroelectric plant. However, a couple of bills were passed last August that should help revive hydroelectric power and potentially add 60 gigawatts of renewable energy to the grid.
The Hydropower Regulatory Efficiency Bill will streamline small hydroelectric projects and allow power companies to add generation to the nation's 80,000 untapped dams. And the Small Conduit Hydropower Development Bill will add renewable capacity at government property and irrigation canals. Though there's no plan to allow companies to build new dams and hydroelectric plants elsewhere, these two bills could bring a rise in renewable generation in the coming years.