The lower heating value (also called energy value, or heat of combustion, or calorific value) is the energy (heat) produced by the combustion of the fuel/material without condensation of the flue gas.

Fuel | Energy value [MJ/kg] | Energy value [kWh/kg] | Density [kg/litre] | Energy value [kWh/litre] |
---|---|---|---|---|

Diesel fuel | 44,4 | 12,33 | 0,835 | 10,30 |

Gas (benzine) | 43,6 | 12,11 | 0,68 | 8,24 |

LPG | 46,1 | 12,81 | 0,52 | 6,66 |

Methane | 52 | 14,44 | 0,656 | 9,48 |

Coal (coke) | 29,6 | 8,22 | 2 | 16,44 |

Charcoal (from wood) | 31,5 | 8,75 | 0,4 | 3,50 |

Dry wood | 17 | 4,72 | 0,8 | 3,78 |

Hydrogen | 130 | 36,11 | 0,0899 | 3,25 |

Sugar | 17 | 4,72 | 1,6 | 7,56 |

Peanut butter | 24,6 | 6,83 | 00.08.00 | 0,04 |

Seed oil | 37 | 10,28 | 0,92 | 9,46 |

Butter | 30 | 8,33 | 0,92 | 7,67 |

Wood’s energy value varies maximum 15% between different types of wood.

## Converting the value to other units

To change the unit of measurement, just multiply the starting value by the** unit factor FU = 1**, to eliminate the unwanted part of the initial unit of measurement. If necessary, use the inverse (1 / FU), which is still 1.

1 = 1 kWh / 3.6 MJ

1 = 4.186 kJ / 1 kcal

## Example 1: We want to convert 10 kWh into Joules

10 kWh * (3.6 MJ / 1 kWh). = 36 MJ.

Note how kWh in the numerator and kWh in the denominator cancel out.

## Example 2: we want to convert 1 kWh into kcal

1 kWh * (3.6 MJ / 1 kWh) * (1000 kJ / 1 MJ) * (1 kcal / 4.186 kJ) = 1 * 3.6 * 1000 * 1 / 4.186 = 860 kcal.

Note how the unit factor also works well for changing the unit prefix (from MJ to kJ in this case).

We just found a new unit factor!

1 = 860 kcal / 1 kWh. (or 1 = 1 kWh / 860 kcal)