Tonne of oil equivalent

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The tonne of oil equivalent (abbreviated toe) is a unit of energy defined as the amount of energy released by burning one tonne of crude oil. It is approximately 42 gigajoules or 11.630 megawatt-hours, although as different crude oils have different calorific values, the exact value is defined by convention; several slightly different definitions exist. The toe is sometimes used for large amounts of energy.

Contents

Multiples of the toe are used, in particular the megatoe (Mtoe, one million toe) and the gigatoe (Gtoe, one billion toe). A smaller unit of kilogram of oil equivalent (kgoe or koe) is also sometimes used denoting 1/1000 toe.

A related concept is the physical quantity oil-equivalent mass (or mass of oil equivalent), [1] [2] expressed in the ordinary units of mass and its multiples: kilogram (kg), megagram (Mg) or tonne (t), etc.

Definitions

The International Energy Agency defines one tonne of oil equivalent (toe) to be equal to: [3]

Conversion into other units:

Some other sources and publications use divergent definitions of toe, for example:

Conversion factors

Tonne of oil equivalent should be used carefully when converting electrical units. For instance, BP's 2022 report used a factor of 40% efficiency (the average efficiency of a standard thermal power plant in 2017), or roughly 16.8 GJ per toe, when converting kilowatt-hours to toe. BP's model is also based on the assumption that efficiency will increase linearly to 45% by 2050. [12]

Derived units

For multiples of the tonne of oil equivalent, it is more usual to speak of millions of tonnes of oil equivalent and kilotonnes of oil equivalent (ktoe).

MultipleNameSymbol
103kilotonne of oil equivalentktoe
106megatonne of oil equivalentMtoe

See also

References

  1. Pohl, W.L. (2011). Economic Geology: Principles and Practice. Wiley. p. 523. ISBN   978-1-4443-3663-4 . Retrieved 2025-03-05.
  2. "Glossary". AdEPorto. Retrieved 2025-03-05.
  3. "Unit converter and glossary". International Energy Agency. December 2016. Retrieved 22 December 2019.
  4. 1 2 3 American Physical Society
  5. "OPEC Annual Statistical Bulletin 2014 - Conversion Factors". Archived from the original on 2015-05-09.
  6. Definition at 41.85 GJ
  7. "Unit Conversion Factors | Society of Petroleum Engineers". Archived from the original on 2015-02-02.
  8. Biofuels in the European Union progress report
  9. IEA Statistics
  10. The Society of Petroleum Engineers
  11. World Energy Council Archived 2008-05-29 at the Wayback Machine
  12. "BP Statistical Review of World Energy 2022" (PDF). Retrieved 2023-02-22.