Ton of oil equivalent
Encyclopedia
The tonne of oil equivalent (toe) is a unit of energy
: the amount of energy released by burning one tonne
of crude oil, approximately 42 GJ
(as different crude oils have different calorific values, the exact value of the toe is defined by convention; unfortunately there are several slightly different definitions as discussed below).
The toe is sometimes used for large amounts of energy
, as it can be more intuitive to visualise, say, the energy released by burning 1000 tonnes of oil than 42,000 billion
joule
s (the SI
unit of energy).
Multiples
of the toe are used, in particular the megatoe (Mtoe, one million toe) and the gigatoe (Gtoe, one billion toe).
/OECD define one toe to be equal to 41.868 GJ
or 11.63 MWh.
Some organisations use other definitions of toe, for example:
It is important to note that toe should be used carefully when converting electrical units - for instance, BP's 2007 report used a factor of 38% efficiency (the average efficiency of OECD thermal generating units in 2006), or roughly 16 GJ per toe, when converting kilowatt-hours to toe.
Units of energy
Because energy is defined via work, the SI unit for energy is the same as the unit of work – the joule , named in honour of James Prescott Joule and his experiments on the mechanical equivalent of heat...
: the amount of energy released by burning one tonne
Tonne
The tonne, known as the metric ton in the US , often put pleonastically as "metric tonne" to avoid confusion with ton, is a metric system unit of mass equal to 1000 kilograms. The tonne is not an International System of Units unit, but is accepted for use with the SI...
of crude oil, approximately 42 GJ
Joule
The joule ; symbol J) is a derived unit of energy or work in the International System of Units. It is equal to the energy expended in applying a force of one newton through a distance of one metre , or in passing an electric current of one ampere through a resistance of one ohm for one second...
(as different crude oils have different calorific values, the exact value of the toe is defined by convention; unfortunately there are several slightly different definitions as discussed below).
The toe is sometimes used for large amounts of energy
Energy
In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...
, as it can be more intuitive to visualise, say, the energy released by burning 1000 tonnes of oil than 42,000 billion
1000000000 (number)
1,000,000,000 is the natural number following 999,999,999 and preceding 1,000,000,001.In scientific notation, it is written as 109....
joule
Joule
The joule ; symbol J) is a derived unit of energy or work in the International System of Units. It is equal to the energy expended in applying a force of one newton through a distance of one metre , or in passing an electric current of one ampere through a resistance of one ohm for one second...
s (the SI
Si
Si, si, or SI may refer to :- Measurement, mathematics and science :* International System of Units , the modern international standard version of the metric system...
unit of energy).
Multiples
SI prefix
The International System of Units specifies a set of unit prefixes known as SI prefixes or metric prefixes. An SI prefix is a name that precedes a basic unit of measure to indicate a decadic multiple or fraction of the unit. Each prefix has a unique symbol that is prepended to the unit symbol...
of the toe are used, in particular the megatoe (Mtoe, one million toe) and the gigatoe (Gtoe, one billion toe).
Definitions
The IEAInternational Energy Agency
The International Energy Agency is a Paris-based autonomous intergovernmental organization established in the framework of the Organisation for Economic Co-operation and Development in 1974 in the wake of the 1973 oil crisis...
/OECD define one toe to be equal to 41.868 GJ
Joule
The joule ; symbol J) is a derived unit of energy or work in the International System of Units. It is equal to the energy expended in applying a force of one newton through a distance of one metre , or in passing an electric current of one ampere through a resistance of one ohm for one second...
or 11.63 MWh.
Some organisations use other definitions of toe, for example:
- 1 toe = 42 GJ
- 1 toe = 41.87 GJ
- 1 toe = 7.11, 7.33, or 7.4 barrel of oil equivalentBarrel of oil equivalentThe barrel of oil equivalent is a unit of energy based on the approximate energy released by burning one barrel of crude oil. The US Internal Revenue Service defines it as equal to 5.8 × 106 BTU...
(boe) - 1 tonne petroleum equivalent (TPE), as used in renewable energyRenewable energyRenewable energy is energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable . About 16% of global final energy consumption comes from renewables, with 10% coming from traditional biomass, which is mainly used for heating, and 3.4% from...
, 45.217 GJ.
Conversion factors
- 1 barrel of oil equivalentBarrel of oil equivalentThe barrel of oil equivalent is a unit of energy based on the approximate energy released by burning one barrel of crude oil. The US Internal Revenue Service defines it as equal to 5.8 × 106 BTU...
(boe) contains approximately 0.146 toe (i.e. there are approximately 6.841 boe in a toe). - 1 t diesel = 1.01 toe
- 1 m3 diesel = 0.98 toe
- 1 t petrol = 1.05 toe
- 1 m3 petrol = 0.86 toe
- 1 t biodieselBiodieselBiodiesel refers to a vegetable oil- or animal fat-based diesel fuel consisting of long-chain alkyl esters. Biodiesel is typically made by chemically reacting lipids with an alcohol....
= 0.86 toe - 1 m3 biodiesel = 0.78 toe
- 1 t bioethanol = 0.64 toe
- 1m3 bioethanol = 0.51 toe
- 1 MWh = 0.086 toe (therefore 1 toe = 11630.0 KWh)
- at thermal power plant, 1 MWh generated with 0.22 toe fuel or 0.39 MWh with 0.086 toe (39% thermal to electrical conversion efficiency)
It is important to note that toe should be used carefully when converting electrical units - for instance, BP's 2007 report used a factor of 38% efficiency (the average efficiency of OECD thermal generating units in 2006), or roughly 16 GJ per toe, when converting kilowatt-hours to toe.
See also
- Conversion of unitsConversion of unitsConversion of units is the conversion between different units of measurement for the same quantity, typically through multiplicative conversion factors.- Process :...
- Energies per unit mass