The tables below show the conversion factors for converting between different units of energy and typical calorific values of fuels.
Energy Conversion Factors
| |
Unit |
x |
Factor |
= |
S.I. Unit |
x |
Factor |
Unit |
| Energy |
therm |
x |
105.506 |
= |
MJ |
x |
0.00948 |
therm |
| |
hp h |
x |
2.684 |
= |
MJ |
x |
0.3726 |
hp h |
| |
kWh |
x |
3.6 |
= |
MJ |
x |
0.2778 |
kWh |
| |
Btu |
x |
1.05506 |
= |
kJ |
x |
0.9478 |
Btu |
| |
therm |
x |
29.31 |
= |
kWh |
x |
0.03412 |
therm |
| |
|
|
|
|
|
|
|
|
| Power |
hp |
x |
0.7457 |
= |
kW |
x |
1.341 |
hp |
| |
Btu/h |
x |
0.2931 |
= |
W |
x |
3.412 |
Btu/h |
Convert to kWhThe following table gives the number you need to multiply by to get from a variety of different units to kWh (note that some of these are specific to certain fuel types).
Unit |
= |
kWh |
| 1 tonne of oil equivalent |
= |
11,630 kWh |
| 1 therm |
= |
29.31 kWh* |
| 1 Giga joule (Gj) |
= |
277.8 kWh |
| 1 British thermal unit (BTU) |
= |
0.00029 kWh |
| 1 cubic foot natural gas |
= |
0.313 kWh* |
| 1 cubic metre natural gas |
= |
11.06 kWh* |
| 1 litre fuel oil |
= |
11.69 kWh* |
*derived from Digest of UK Energy Statistics 2003
Typical heat content of common fuelsWhere fuels are purchased or measured by volume or weight the calorific value of the fuel is needed to convert to energy units. This should be specified by the fuel supplier, but where this data is not available the typical values given below can be used (all figures from Digest of UK Energy Statistics 2003 table A.1 estimated average gross calorific values of fuels).
|
|
Gross calorific value |
| Fuel Oil |
Kerosene |
28 sec |
46.2 MJ/kg |
| |
Gas/diesel Oil |
35 sec |
45.6 MJ/kg |
| |
Fuel Oil |
|
43.4 MJ/kg |
| Liquid Petroleum Gas (LPG) |
Butane |
49.4 MJ/kg |
| Natural Gas |
|
39.8 MJ/m3 |
To convert energy use to carbon dioxide visit our Conversion Factors section.
|