Coal

• Coal storage is simpler than gas or oil storage.winter coal image by Rick Smith from Fotolia.com
  
  The most stable form of fossil fuel, coal, has been used for thousands of years. It is safely stored and relatively abundant. Coal emissions must be scoured to reduce harmful pollutants. Gypsum is a byproduct of this cleaning process. Coal is still widely available in the U.S. Organizations such as the Appalachian Citizens Law Center consider mountaintop removal coal mining environmentally destructive.
  
  

Crude Oil

• Jet fuel is another crude oil product.fuel truck image by Steve Mann from Fotolia.com
  
  Petroleum, or crude oil, products include gasoline, diesel fuel and kerosene. Oil is used in the manufacture of plastics. As a fuel, oil is more easily extracted than other fossil fuels and its liquid form makes transport and storage simpler. Oil must be refined and stored, which adds to cost. About half of the U.S.'s petroleum is imported, according to the U.S. Energy Information Administration. Burned fuel can emit carbon dioxide, carbon monoxide, sulfur dioxide and particulate matter.
  
  

Propane

• Propane is extracted during the drilling of oil or natural gas. It can be pressurized and liquefied for transport and storage in tanks. This makes it advantageous for use in more remote areas without pipeline access.
  
  

Natural Gas

• Domestic fuel sources help avoid risks of overseas fuel transport.fuel tanker image by Paula Gent from Fotolia.com
  
  Natural gas, composed largely of methane, is 90 percent efficient, according to Orange and Rockland Utilities in New York. It is normally made available through a pipeline and pipe storage system. It can be used as raw material for production of fertilizers, medicines and explosives. Natural gas can be a combustion hazard.