The National Academies: What You Need To Know About Energy

The National Academies

What You Need To Know About Energy

Alternatives to Conventional Oil

There are several “unconventional” petroleum sources, materials from which oil can be extracted—at a cost. Resources are abundant and could greatly impact the U.S. oil supply in the future. The three largest are oil shale (rock that releases petroleum-like liquids when heated in a special chemical process); tar sands (heavy, thick, black oil mixed with sand, clay, and water); and heavy crude oil (thicker and slower flowing than conventional oil).

A region covering parts of Colorado, Utah, and Wyoming contains oil shale totaling about three times the proven oil reserves of Saudi Arabia.

The most extensive deposits of all three are in North and South America. A region covering parts of Colorado, Utah, and Wyoming contains oil shale totaling about three times the proven oil reserves of Saudi Arabia. About two-thirds of the world’s supply of tar sands (estimated at 5 trillion barrels, though not all of it recoverable) is found in Canada and Venezuela. Venezuela also has the largest known reserves of heavy crude oil, estimated at 235 billion barrels.

However, extracting these resources is much more costly, energy intensive, and environmentally damaging than drilling for conventional oil. The processes by which we mine and refine oil shale and tar sands to produce usable oil, for example, involve significant disturbance of the land, extensive use of water (a particular concern in dry regions where oil shale is often found), and potential emissions of pollutants to the air and groundwater. In addition, more energy goes into these processes than into extracting and refining conventional oil, and more CO2 is emitted. But as conventional oil costs rise, greater attention is being focused on alternative sources and on overcoming the challenges associated with their use. Canada already produces more than a million barrels of oil per day from tar sands, and some companies are interested in pursuing oil shale in the United States, probably using below-ground techniques to extract the oil without mining the shale.

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Energy Hands-on

What do you know about energy?

Which of the following is frequently used as a unit of measurement for the energy content of fuels?

  • Sorry, that’s incorrect.

    The British Thermal Unit, or Btu, is frequently used as a measure for energy content of fuels. One gallon of gasoline contains about 124,000 Btu.

  • Correct!

    The British Thermal Unit, or Btu, is frequently used as a measure for energy content of fuels. One gallon of gasoline contains about 124,000 Btu.

  • Sorry, that’s incorrect.

    The British Thermal Unit, or Btu, is frequently used as a measure for energy content of fuels. One gallon of gasoline contains about 124,000 Btu.

  • Sorry, that’s incorrect.

    The British Thermal Unit, or Btu, is frequently used as a measure for energy content of fuels. One gallon of gasoline contains about 124,000 Btu.

Energy Defined

Particulate Matter

Extremely small particles of solid or liquid droplets suspended in either a liquid or gas. Particulate matter is a common emission from the combustion of fossil fuels and can increase the risk of health problems. Examples include dust, smoke, aerosols, and other fine particles.

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National Academies Press

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