Most power in this country is produced by electric generating turbines. In 1831, Michael Faraday discovered that if an an electric conductor, like a copper wire, is moved through a magnetic field, electric current will flow through the conductor. The modern power plant generators are based on this very principal, although on a much larger scale. To turn these massive machines, the most often used method is to turn water into steam, pressurize the steam, and run it over the blades of a turbine causing it to spin. The current figures for electric power sources as of Aug. 2009 (from d.o.e. website) is as follows:
- Coal-fired plants 45.4%
- Nuclear plants 21.0%
- Natural gas-fired plants 20.7%
- Hydroelectric power 7.5%
- Alternative sources (geothermal, solar, and wind) 4.2%
- Other fossil fuels 1.2%
Coal-fired plants: The water for the turbines is heated by burning coal, and it is a particularly dirty source of energy. This method releases around 40% of the total U.S. carbon dioxide emissions, about 50% of total particle pollution, and large amounts of other pollutants. When the Clean Air Act of the 1970s was passed, Congress grandfathered in older power plants making them exempt from modern regulations. As a result, today most existing power plants use coal, and are between 30-50 years old and are up to 10 times dirtier than new power plants.These plants have been around a long time and will continue to be around a long time. With the growing threat of global warming people are just starting to realize the hidden cost of coal fired electricity.
Natural gas-fired plants: Cleaner than coal fired plants releasing about half the amount of carbon dioxide. Natural gas fired plants may replace a lot of the coal fired plants when they finally get too old. Better than coal, yet still a big polluter.
Nuclear plants: Nuclear power has major drawbacks like nuclear waste, and the ability to release lethal radiation into the atmosphere. Nuclear reactors have been around for 60 years and these potentially lethal drawbacks have yet to be solved. Does not seem to be the answer to our energy problems at this time.
Hydroelectric power: A popular method to produce electricity. A dam is built, water and gravity do the rest. This is a great method with no pollution, and is a good source of energy. There will not be many more dams built however, you can only build so many. Great power source without the ability to grow.
Alternative sources: Free power and nonpolluting. Geothermal is not practical for most people. Wind power is being used by many people who have the room and live in the right location. Solar power can be used almost anywhere and is very useful for powering individual households. So why is its use growing so slowly? There is a very large group of people who want to eliminate their power bill and help the environment, but until recently the prohibitive start up costs have not made this possible. Today more and more people are discovering that they can build their own solar panels. Using readily available materials and a easy to understand guide they are being built for a fraction of the old cost. If this sounds interesting to you check out this complete guide to get more information.
Electric Generation Methods and Solar Power