The energy equivalent of a fuel is the total energy contained in a specific volume or measurable quantity of that fuel.  Liquid fuels such as propane, fuel oil, kerosene, etc. are generally measured on a volume basis such as a gallon or liter.  Natural gas is also measured on a volume basis of cubic feet or cubic meters, with a therm being the equivalent of 100 cubic feet.  Electricity is generally metered in kilowatt hours(kWh).  The energy equivalent in common fuels are provided in the list below including energy values for wood and shelled corn which have gained popularity.

Fuel Type                                             Energy Equivalent

Electricity                                    3,412 Btu/kW hr

Natural Gas                               100,000 Btu/Therm(1)

Propane                                     92,000 Btu/gal

Fuel Oil, No.2                            140,000 Btu/gal

Kerosene, No.1                          134,000 Btu/gal

Wood, cord                         20,000,000 Btu/cord(2)

Wood, pellets                      16,500,000 Btu/Ton

Shelled Corn                           392,000 Btu/Bushel

(1) 1 Therm - 100 cubic feet

(2) 1 cord - 4feet x 8 feet x 4 feet stack, tightly packed