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.
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), 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:
- 1 toe = 11.63 megawatt-hours (MWh)
- 1 toe = 41.868 gigajoules (GJ)
- 1 toe = 10 gigacalories (Gcal) –
- 1 toe = 39,683,207.2 British thermal units (BTU)
- 1 toe = 1.42857143 tonnes of coal equivalent (tce)
Conversion into other units:
- 1 toe = 7.33 barrels of oil equivalent (boe)
Some other sources and publications use divergent definitions of toe, for example:
- 1 toe = 10.7 gigacalories (Gcal) –