Energy Conversion Factors

Joule (J) 				 (Metric unit, also kJ = 1000 J)

British thermal unit (Btu)= 1055 J (raise 1lb water 1 deg Fahrenheit)

Calorie (food unit) 	  = 1000 calories = 1kcal = 4184 J = 3.96 Btu
				   (raise 1 kg water 1 degree celsius)

foot-pound (ft-lb) (work) = 1.36 J 

kilowatt-hour (kWh) (electricity) = 3.6 million J = 3413 Btu = 860 Cal

1 gallon of gasoline = 132 million J = 36.6 kWh = 125,000 Btu

1 barrel of oil(42 gallons)  = 6.12 billion J = 1700 kWh = 5.8 million Btu

1 ton of coal = 28.1 billion J = 7800 kWh = 26.6 million Btu

natural gas (1000 cubic feet) = 1.09 billion J = 36.6 kWh = 1.04 million Btu

AA battery: 2850mAh or  0.0038 kWh = 3.3 Calories = 13 Btu

100 QBtu/year = 3.35 TW = 170Gboe/yr = 100 tcf/yr
[QBtu = quadrillion Btu = 10^15 Btu; TW = terawatt = 10^12W; Gboe = billion
barrel of oil equivalent; tcf is trillion cubic feet of natural gas equivalent]