General. A metric unit of energy, especially electrical energy. One megawatt hour equals exactly 3.6 gigajoules (GJ), about 3.412 million Btu, or about 2.655 billion foot pounds
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}