Wow, that's a great question! I had to look up some figures to answer... According to the Wikipedia (who quotes the IRS http://www.irs.gov/pub/irs-drop/n-99-18.pdf), a "BOE" which is a "Barrel of Oil Equivalent" , is 5.8 million BTU. That is equal to 6.117 Tera-Joules or 1.70...