Hydroelectric power as an alternative to carbon producing energy sources is once again becoming a popular idea in the United States. The existing dams and rivers producing hydroelectric power are once again being looked at as a viable source of power.
History of Hydroelectric Power
According to A Study of Hydroelectric Power: From a Global Perspective to a Local Application, ancient Greeks used wooden water wheels to convert kinetic energy into mechanical energy as far back as 2,000 years ago. In 1882, the first hydroelectric power plant was built in the United States using a fast flowing river. In time began people began creating dams to store water at the most convenient locations in order to best utilize power capacity. Additional engineering and structural changes followed, providing for a much more complicated process in designing a hydroelectric plant.
In the early 1900s. Hydroelectric power was the dominant source of the U.S. electricity generation and in the 1940's, it accounted for 42% of electricity production. (USA Today, 10/27/08)
How Hydroelectric Power Works
The way hydroelectric power works is that water falls due to gravity that causes kinetic energy to be converted into mechanical energy. This is turn can be converted into electrical energy for the power plants. When falling water spins turbines, it turns generators which produce energy.
The College of Earth and Mineral Studies at Pennsylvania State University has classified the plants according to size:
- Micros generate less than 100kW of electricity which can power 1-2 houses.
- Mini facilities can serve an isolated community or small factory by generating 100kW-1MW of electricity.
- Small plants generate 1MW-30MW and are capable of serving an area while supplying electricity to a regional grid.
- Large plants can produce more than 30MW of power.
An evaluation done the College in 2003, showed that hydroelectric power only accounted for about 10% of the total energy produced in the United States. It now has the potential to create 30,000MW of electricity by utilizing 5,677 undeveloped sites. According to Hydro Review magazine (USA Today 10/13/08), utilities are proposing more than 70 projects that would boost U.S. hydroelectric capacity by at least 11,000 megawatts or 11% over the next decade.
Sources of Hydroelectric Power
Sources for hydroelectric power can be from dams as well as strong river flows. With coal prices doubling since last year, big hydroelectric additions are now economically viable. Generators are being added to dams that have none and to expand hydroelectric plants at others.
Actions being taken include:
- Installing hydroelectric power generators on existing dams.
- Replacing or upgrading existing powerhouses.
- Adding water storage.
Hydroelectric Power Opposed by Environmentalists
The main objection by environmental groups to dams is that they trap sediment and often impede the migration of fish such as salmon. The World Dam Commission Report, an independent international multi-stake process addressed the controversial issues associated with large dams in 2000. It provided a unique opportunity to bring into focus the many assumptions and paradigms that are at the center of the search to reconcile economic growth, social equity, environmental conservation and political participation in the changing global context.
Hydroelectricity can meet the growing demand for electricity in the U.S. As concerns grow about the increasing cost of fossil fuels such as coal and natural gas, and the diminishing amounts of oil available around the world, the scramble for clean energy is making hydroelectricity appear to be a more viable alternative.
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