Power plants (Encyclopedia of Environmental Issues, Revised Edition)
Electric power is produced from a number of sources. Of the 4,119 million megawatt-hours of electricity generated in the United States in 2008, coal contributed 48.2 percent; natural gas, 21.4 percent; nuclear, 19.6 percent; hydroelectric, 6.0 percent; other renewable resources such as solar, geothermal, wind, and biomass, 3.1 percent; petroleum, 1.1 percent; and other sources, 0.6 percent. In other countries, the relative utilization of fuels varies depending on what local resources are available.France has little coal and oil, so for most of its electricity (more than 75 percent) it depends on nuclear power. China’s increasing industrialization is largely fueled by its vast coal resources, from which it generates roughly 80 percent of its electricity.
Large-scale electric power facilities and related infrastructure tend to present certain environmental challenges regardless of the fuels they consume. Massive centralized power generation facilities require substantial amounts of land, and environmentally irresponsible operations can leave the sites badly polluted and the neighboring land significantly devalued. Power transmission lines have a negative aesthetic impact, particularly in natural areas. These large structures can also disrupt wildlife habitats, and where they cross agricultural land they have the potential to impede farming operations. If a power plant diverts water from a river to serve as a coolant and then returns the...
(The entire section is 231 words.)
Power Generation Using Fossil Fuels (Encyclopedia of Environmental Issues, Revised Edition)
Coal is the most abundant of the world’s fossil fuels. Mining, transportation, and combustion of coal create a host of environmental problems. Surface mining of coal defaces the landscape and causes erosion. Deep mining is a hazardous occupation for miners because of long-term lung effects; the coal-mining industry also has a history of deadly underground explosions. Whenever coal is transported or stored, care must be taken to minimize the risk of spontaneous combustion.
Oil drilling, be it on land or offshore, can result in massive accidental releases to the environment, a well-known example being the BP Deepwater Horizon oil spill in the Gulf of Mexico that continued for months during the spring and summer of 2010. Oil is commonly transported by pipelines and ocean tankers, both of which have a history of ruptures and spills. Environmental releases of oil can harm aquatic organisms, waterfowl and seabirds, other wildlife, and their ecosystems. Natural gas pipelines are also problematic, as leaks can lead to damaging and deadly explosions such as the one that occurred in San Bruno, California, in 2010.
When coal, oil, or natural gas is burned at an electric power plant, high-pressure steam is produced to turn a turbine that is connected to a generator. Some coal contains as much as a 10 percent sulfur impurity, which is converted to gaseous sulfur dioxide during burning. Oxygen and...
(The entire section is 536 words.)
Power Generation Using Other Sources (Encyclopedia of Environmental Issues, Revised Edition)
Nuclear power plants offer one alternative to fossil-fuel-burning plants. The major benefit of nuclear power is that no chemical burning takes place, so no fly ash, acid rain, or greenhouse gases are produced. A common objection to this power generation technology stems from the possibility that an accident could release radioactivity into the environment. Such a release occurred during the 1986 Chernobyl disaster in Ukraine, which remains the worst nuclear reactor accident in the history of the industry. Opponents of nuclear power also point to the problem of long-term nuclear waste storage, which presents both technical and sociopolitical challenges.
Hydroelectric power plants use water, a renewable, nonpolluting resource, to generate electricity, but they also have environmental disadvantages. When a new hydroelectric dam is built, the stored water often fills a scenic canyon or floods farmland near the river. During extended droughts, as happened in the Pacific Northwest during the 1980’s, consumers of hydroelectric power are faced with electric power shortages. The impact of dam construction on downstream water supplies can cause friction among communities, states, or nations. The greatest hazard of a dam is the large quantity of water stored behind it. If a dam experiences catastrophic failure, as China’s Banqiao Reservoir did in 1975, the resulting loss of life and property downstream can be...
(The entire section is 494 words.)
Further Reading (Encyclopedia of Environmental Issues, Revised Edition)
Ayres, Robert U., and Ed Ayres. Crossing the Energy Divide: Moving from Fossil Fuel Dependence to a Clean-Energy Future. Upper Saddle River, N.J.: Wharton School Publishing, 2010.
McCully, Patrick. Silenced Rivers: The Ecology and Politics of Large Dams. Enlarged ed. London: Zed Books, 2001.
Murray, Raymond L. Nuclear Energy: An Introduction to the Concepts, Systems, and Applications of Nuclear Processes. 6th ed. Burlington, Vt.: Butterworth-Heinemann/Elsevier, 2009.
National Research Council. Electricity from Renewable Resources: Status, Prospects, and Impediments. Washington, D.C.: National Academies Press, 2010.
Visgilio, Gerald Robert, and Diana M. Whitelaw, eds. Acid in the Environment: Lessons Learned and Future Prospects. New York: Springer, 2007.
(The entire section is 102 words.)