Convert t hard coal to terajoule

The joule is tiny, so the everyday unit is the megajoule: 1 kWh is 3.6 MJ, a litre of petrol holds about 33 MJ and a litre of diesel 36, and Australian and New Zealand food labels count in kilojoules towards a daily 8,700 kJ (8.7 MJ). Gas bills in Canada are in gigajoules, 1 GJ being 278 kWh or roughly 26 m³ of gas, and a full 50-litre tank of petrol is 1.7 GJ. National statistics use petajoules and exajoules: the UK consumes around 7 EJ of primary energy a year, the world some 620 EJ.

Energy statistics reduce every fuel to a common yardstick. The tonne of oil equivalent is defined by the IEA as 41.868 GJ (11.63 MWh), roughly the energy in a tonne of crude; national energy balances are in Mtoe. The barrel of oil equivalent is used by oil companies, and its exact value varies between them, so figures are approximate. The tonne of coal equivalent is 29.3 GJ (7 million kcal), which Germany writes as SKE (Steinkohleeinheit). Natural gas is counted by volume or, as LNG, by mass: a billion cubic metres of gas is about 0.9 Mtoe.