In recent years, local, national and international political emphasis has moved toward providing environmentally sound methods of moving the modern, and increasingly industrialized, world. Several possibilities have come to the forefront as research and development of alternative fuels has progressed. One of the initial, and still fundamental, issues with these fuels is their viability given current and projected energy demands. Another is the ability and economics of instituting said alternatives to lower consumption and reliance upon petroleum based fuels and byproducts.
The United States Department of Energy has recognized seven alternative fuel sources: natural gas, propane, biodiesel, ethanol, methanol, electricity, and hydrogen. Natural gas is both a vastly more abundant resource and provides much cleaner emissions than traditional petroleum based fuels. It is available in the modern market, though compatible vehicles and wide-spread distribution to the masses is lacking. Propane is a specific natural gas prevalently used in modern industrial vehicles and has made a move into the consumer market as a viable alternative. Biodiesel based fuels are derived from the oils of various vegetables and certain animals fats. Ethanol is another type of biofuel commonly derived from corn in the United States and is an alcoholic byproduct. Methanol is an alcohol-based fuel no longer being pursued as a possible alternative but still serves as a source of fuel in lieu of gasoline or diesel. Electricity can be derived in several ways but its source is also a matter of contention as most electricity that could be converted to fuel in the United States is currently produced in coal burning power plants. Hydrogen represents both the most viable alternative to current petroleum based fuels and the most difficult to adapt to current industrialized needs.
Currently these fuels serve as supplements or alternatives on a very small, financially inefficient scale. Though, innovation and development continue in the field of alternative fuels as emphasis and enthusiasm for these fuels rises alongside the prices at the pump. Coupled with a growing awareness of global temperature trends and environmental conscientiousness, the potential for growth in the field of alternative fuels is great.