Hydroelectric Power

Nearly a fourth of the world’s energy is consumed by the United States. Most of this energy comes from burning fossil fuels, such as oil, coal, and natural gas. The availability of these fossil fuels is rapidly declining, as the world’s increasing population is proportional to its energy consumption. At the present estimated expenditure rate, the world’s reserve of fossil fuels will be depleted within the next century. This has caused great concern among developed nations to find a suitable alternative energy source.

However, this is not the only reason for concern. The burning of fossil fuels has produced a buildup of greenhouse gases in our atmosphere, which has caused an increase in the Earth’s temperature. These gases, which are carbon dioxide, methane, nitrous oxide, and chlorofluorocarbons, are known to impede the Earth’s infrared radiation from escaping into space, and thus function to sustain the Earth’s moderately warm temperature. If greenhouse gas emissions are not reduced, the Earth could experience a significant rise in temperature. This would result in the melting of the polar ice caps, the rising of sea level, causing catastrophic coastal flooding, and major environmental changes, having dangerous repercussions for agricultural efficiency.

The only solution for this growing problem is to utilize more renewable energy sources. These include hydroelectric power, geothermal energy, wind power, and solar power. Currently, the most commonly used renewable energy source is hydroelectric power. This form of power comes from the flow of water from a higher to a lower level, and obtained by means of waterwheels or hydraulic turbines. Water is a readily available natural resource, and shows great potential for supplying the world with the energy that it needs.

Since the dawn of civilizations, man has harnessed the power of flowing water. The use of waterwheels dates from ancient Egypt, Greece, and Rome, where they were used for the milling of grain. With the availability of cheap slave and animal labor, however, the use of waterwheels did not become widespread. In the early nineteenth century, waterwheels helped the growth of textile, leather, and machine shop industries in the American colonies. The use of waterwheels increased, aiding the development of early industrial cities, until the middle of the nineteenth century when canals to the Midwestern United States offered coal as a more economical substitute.

The birth of hydroelectric power came at the turn of the twentieth century with the development of the electric generator, and improvements of hydraulic turbines. Power companies built several small hydroelectric power plants in the mountainous regions of the United States, and by 1920 hydroelectric power plants accounted for forty percent of the electric power produced nationwide. During this time, hydroelectric power plants were unable to compete with larger, more cost efficient steam power plants. In 1933, however, the Tennessee Valley Authority started government participation in the building of large-scale hydroelectric power plants that could compete with the steam power plants.

Most hydroelectric facilities depend on a large upstream reservoir where water flow can be controlled, and a nearly constant water level can be guaranteed. These reservoirs are created by the building of dams that stop the flow of water. The water from these reservoirs flows through the penstocks, which