Energy densities of fuel

The specific energy of a fuel can be expressed as the energy per kilogram, with unit MJ/kg, or as the equivalent electrical energy that could theoretically be obtained from one kilogram of the fuel, with unit kWh/kg.

Energy densities by mass and volume

Energy carrierStateSpecific energy (MJ/kg)Energy density (MJ/L)Specific energy (kWh/kg)Energy density (kWh/L)
Hydrogen (H2)Gas, 690 bar, 15°C141.95.339.41.5
Methane (CH4)Gas, 1.013 bar, 15°C55.60.03815.4410.5
Methanol (CH3OH)Liquid19.715.65.474.33
DieselLiquid45.638.612.710.7
PetrolLiquid46.434.212.911.6
Coal (anthracite)Solid26-3334-437.2-9.29.4-11.9
Coal (lignite)Solid10-202.8-5.6
WoodSolid18135

Source: https://en.wikipedia.org/wiki/Energy_density