The United States depends on fossil fuels, like oil and coal, for energy. According to experts these sources will exhaust by the year 2050. Fossil fuels also pollute the environment. So we need to search for alternative energy sources which are reliable and renewable.Wind power is the force of the wind harnessed by windmills and wind turbines that convert it into electricity. Because wind is a clean and renewable source of energy, modern wind turbines are being installed in many countries to supplement more traditional sources of electric power, such as burning coal. After the oil crisis of the 1970s, many countries launched programs to develop modern wind turbines. While many of these programs failed, Denmark was successful in developing one. Countries such as the United States h ...view middle of the document...
The development of hydroelectric power requires storage lakes, dams, bypass canals, and the installation of large turbines and electric generating equipment. Worldwide, hydroelectric power represented 19 percent of the total energy generated in 1998, the most recent year for which data are available. In many countries, hydroelectric power is the dominant source of electric power. Canada, the largest producer of hydroelectric power in the world, generated 340.3 billion kilowatt-hours in 1999, about 60 percent of the nation's electric power. Hydroelectric-power generation in the United States increased from about 16 billion KWH in 1920 to 305.6 billion KWH in 1999, this is only eight percent of total consumption.Solar power is the energy from the sun that is converted into thermal or electrical energy. The direct collection of solar energy involves artificial devices, called solar collectors, that are designed to collect the energy, sometimes through prior focusing of the sun's rays. The energy, once collected, is used in a thermal process or a photo-electric, or photo-voltaic, process. In thermal processes, solar energy is used to heat a gas or liquid, which is then stored or distributed. In the photo-voltaic process, solar energy is converted directly to electrical energy without intermediate mechanical devices. Solar collectors are of two fundamental types: flat plate collectors and concentrating collectors. A futuristic scheme that has been proposed to produce power on a large scale envisions placing giant solar modules in geosynchronous earth orbit, where energy generated from sunlight would be converted to microwaves and beamed to antennas on earth for re-conversion to electric power.Unless we contrive more efficient ways to develop alternative energy within this century we will face major problems because energy consumption is increasing year by year, so do the pollution.
