Thetonne of oil equivalent (abbreviatedtoe) is aunit of energy defined as the amount of energy released by burning onetonne ofcrude oil. It is approximately 42gigajoules or 11.630megawatt-hours, although as different crude oils have differentcalorific values, the exact value is defined by convention; several slightly different definitions exist. Thetoe is sometimes used for large amounts ofenergy.
Multiples of thetoe are used, in particular themegatoe (Mtoe, one million toe) and the gigatoe (Gtoe, one billion toe). A smaller unit ofkilogram of oil equivalent (kgoe orkoe) is also sometimes used denoting 1/1000 toe.
A related concept is thephysical quantityoil-equivalent mass (ormass of oil equivalent),[1][2] expressed in the ordinaryunits of mass and its multiples:kilogram (kg),megagram (Mg) or tonne (t), etc.
TheInternational 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:
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]
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).
| Multiple | Name | Symbol |
|---|---|---|
| 103 | kilotonne of oil equivalent | ktoe |
| 106 | megatonne of oil equivalent | Mtoe |
