Compressed air is a gas, or a combination of gases, that has been put under greater pressure than the air in the general environment. Current applications using compressed air are numerous and diverse, including jackhammers, tire pumps, air rifles, and aerosol cheese. According to proponents, compressed air also has a great deal of potential as a clean, inexpensive, and infinitely renewable energy source. Its use is currently being explored as an alternative to fossil fuels.
In 1991, the first compressed air energy storage (CAES) plant in the United States opened in McIntosh, Alabama. The world's largest CAES plant, planned for Norton, Ohio, is expected to store sufficient energy to provide electric power for 675,000 homes for two days. Another product that uses compressed air is the so-called "air car" currently in development by several manufacturers, and expected to be on the market within the next few years. According to "How Stuff Works," one such car, the e.Volution, will run 120 miles without refueling, at a cost of about 30 cents.
Compressed air in spray cans (sometimes called canned air ) is often used to clean things that are especially delicate or sensitive, such as keyboards or the inside of computer cases.