Convert british thermal unit to exajoule

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.

The British thermal unit, the heat that warms a pound of water by one degree Fahrenheit (1,055 J), is now mostly an American unit. US gas bills are in therms of 100,000 Btu (29.3 kWh), wholesale gas is priced per million Btu (MMBtu), and national energy statistics are in quads, 10¹⁵ Btu: the US uses about 100 quads a year. The ton-hour is the cooling delivered by one refrigeration ton over an hour, 12,000 Btu.