With approximately 4.38 million barrels spilled, how much energy would that oil have supplied?
Enough to power 674,563 US homes for one year.
Energy from oil can be understood via the Barrel of Oil Equivalent or BOE, which is a unit of energy based on the approximate energy released by buring 1 barrel of crude oil. From this conversion, a single barrel of oil yields approximately 5,800,000 BTU, and from this the oil spilled into the gulf could be converted to about 25.409 trillion BTU, or about 7.45 million kilowatt hours (kWh).
According to the US Energy Information Administration, in 2008 the average annual electricity consumption for a U.S. residence was 11,040 kWh. According to this number, the energy lost in the spill would be enough to power 674,563 American homes for 1 year.