British thermal unit, a unit of heat energy, used to describe of amount of heat that can be generated by burning oil or gas.
A Btu is defined as the amount of energy required to increase the temperature of 1 pound of water by 1 degree Fahrenheit, at normal atmospheric pressure. Energy consumption is expressed in Btu in this report to allow for consumption comparisons among fuels that are measured in different units. (See Metric Conversion Factors.)
A BTU is the amount of thermal energy required to raise the temperature of one (1) pound of water by one (1) degree Fahrenheit. An MMBTU is equal to one (1) million BTU's.