PHS 100 Environmental Studies:
Professor D. Terrell
Warner Pacific College
November 19, 2010
Society’s Dependence on Energy Resources
As a society we are dependent on energy resources and we have an opportunity to develop an alternative system to satisfy the energy needs of our society. The first water wheel that first generated electricity was built in 1882 and when the United States began building dams to help generate electricity they were small and did not adversely affect the flow of the river. As we began to expand westward, the small dams became insufficient.
The Depression of the 1930's, coupled with widespread floods and drought in the West, spurred the building of great multipurpose Reclamation projects such as Grand Coulee Dam on the Columbia River, Hoover Dam on the lower Colorado River, and the Central Valley Project in California. This was the "big dam" period, and the low-cost hydropower produced by those dams had a profound effect on urban and industrial growth. Farming was tremendously important to America during the war and continues to be today. Reclamation delivers 10 trillion gallons of water delivered to more than 31 million people each year.
The theory is to build a dam on a large river that has a large drop in elevation. Gravity causes it to fall through the penstock inside the dam. At the end of the penstock there is a turbine propeller, which is turned by the moving water. The shaft from the turbine goes up into the generator, which produces the power. Power lines are connected to the generators that carry electricity to homes and businesses.
The reservoir acts much like a battery, storing power in the form of water when demands are low and producing maximum power during daily and seasonal peak periods
There are some major advantages of the hydroelectric power plants is that they do not require any fuel for producing power. The hydroelectric power plants utilize renewable energy of water to generating electricity. Since the hydroelectric power plants do not burn any fuel no pollution is caused by them. It does not emit harmful gases and particulate matter, thus keeps the surrounding atmosphere clean and healthy for living. The life of hydroelectric power plants is longer than the life of thermal power plants. There are some hydroelectric power plants that were built more than 50-100 years ago and are still running with no foreseeable issues. Wind farm life expectancy is only 20 years and coal-fired power plants last about 30 years. Water from the dams can also be used for the irrigation of farm lands thus producing the agriculture outputs throughout the year even in the areas where there is scanty or no rainfall. The dams also help prevent floods in the areas adjoining the large rivers. Since no fuel is required for the hydroelectric power plants, the cost of electricity produced by them is more or less constant. It does not depend on the cost of fuels like coal, oil and natural gas in the international market. The country does not even have to import the fuel for running the hydroelectric power plant thus saving lots of local currency. For the working of hydroelectric power plant very few people are required since most of the operations are automated, thus operating costs of hydroelectric power plants are low. Further, as the hydroelectric power plants become older, the cost of generation of electricity from it becomes cheaper since initial capital cost invested in the plant is recovered over the long period of operations.
It is estimated that the total hydropower that has the potential to be converted into hydroelectricity is about 14 000TWh (tera watt hours), which is five times than the potential hydroelectricity which is being exploited today. There are 82,600 dams in the world - only 3% generate power. It would be great if as a society used the energy produced by these dams instead of letting just lie there.
References
Diesendorf, M. 2004. Comparison of Employment Potential of the Coal and Wind Power Industries. International Journal of Environment, Workplace, and Employment, 82-90.
Khemani, Haresh. 2008. Advantages of Hydroelectric Power Plants. Retrieved from
http://www.brighthub.com/environment/renewable-energy/articles/7728.aspx on November 10,2010
Khemani, Haresh. 2008. Past, Present and Future of Hydroelectric Power Plants - Part 3: Future. Retrieved from http://www.brighthub.com/engineering/mechanical/articles/9017.aspx#ixzz15lBR77iu on November 10, 2010
http://www.usbr.gov/power/edu/history
http://www.scientificamerican.com/article.cfm?id=chinas-three-gorges-dam-disaster
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