Approximately one-third of all energy consumed in the United States is for transportation, which primarily consists of gasoline for automobiles, diesel for trucks, trains, and vessels, and jet fuel for airplanes. Approximately 92% of total transportation energy in 2014 was derived from petroleum products. Of the non-petroleum sources, biomass from corn-based ethanol, which is supported by generous government subsidies, represented the largest source and was used primarily to fuel cars and other light vehicles.
Historically, petroleum has been used for thousands of years in ancient civilizations including Babylon, Egypt, and China. However, the modern history of the petroleum industry is said to have begun in 1846 when Abraham Gessner of Nova Scotia, Canada devised a process to produce kerosene from coal. The first large petroleum refinery was built in Ploesti, Romania in 1856 using locally available oil. The industry grew slowly in the 1800s, primarily producing kerosene for oil lamps. In the early twentieth century, the introduction of the internal combustion engine and its growth for use in automobiles created a market for gasoline. This then created the opportunity for rapid growth of the petroleum industry.
Modern petroleum refineries take crude oil and convert it via a variety of chemical and thermal process into final end products for industrial and commercial use. The primary end-products may be grouped into three major categories: light distillates (such as LPG and gasoline), middle distillates (such as kerosene, diesel, and heating oil), and heavy distillates (such as bunker fuel).
At this time the transportation industry is in the early stages of a transition away from oil distillates to non-traditional sources of energy. This includes electricity, biofuels, natural gas, which is fossil fuel based but has some environmental benefits over petroleum, as well as hydrogen. Non-petroleum energy now makes up the highest percentage of total fuel consumption for transport since 1954, according to a new report from the U.S. Energy Information Administration (EIA).
While this trend is encouraging given that petroleum accounts for over a third of global greenhouse gases, there are still significant challenges that must be overcome. For example, using ethanol provides only marginal benefit over petroleum in terms of greenhouse gas emissions when all aspects of the production of ethanol are taken into consideration. Use of hybrid and all-electric vehicles is growing, but these are still somewhat higher cost transportation options, and new technology in the form of hydrogen fuel cell vehicles is not yet proven commercial.
The Transportation Topics package provides information on a variety of transportation energy topics of general interest to the American public. Key references are provided that can be used to find more detailed information.