The maximum amount of energy that can be supplied
by 1 kg of a fuel is called the energy density of the fuel. Clearly fuels with a high energy
density are more effective than those with a low energy density although their use for a
particular purpose may also depend on cost, availability, toxicity and so on.
(The
figures in the table have been adapted from a number of sources and simplified for ease of
use.)
| Fuel | Energy density | Energy density |
| (MJkg-1) | (MJlitre-1) | |
| Nuclear fusion of hydrogen | 300 000 000 | 425 000 000 |
| Nuclear fission of uranium 235 | 77 000 000 | 1 500 000 000 |
| Liquid hydrogen | 143 | 10 |
| Natural gas (compressed to 200x105 Pa) | 54 | 10 |
| Petrol | 46 | 34 |
| Diesel | 45 | 38 |
| Aviation fuel | 43 | 33 |
| Residential heating oil | 43 | 33 |
| Vegetable oil | 42 | 31 |
| Crude oil | 42 | 37 |
| Liquified natural gas | 37 | 24 |
| Coal (anthracite) | 33 | 72 |
| Charcoal | 29 | |
| Coal (bituminous) | 24 | 20 |
| Wood | 6-18 | 2-3 |
| Liquid hydrogen and liquid oxygen | 13 | 6 |
| Household waste | 8-10 | |
| TNT | 4.2 | 7 |