Frankly, I couldn't care less how much energy we use to produce GDP as I have a hard time believing in this global warming tripe (which is the underpinning for such a statistic). Additionally, a lot of it depends on what industries compile your economy. A tax haven/financial center is obviously going to use less energy than an industrial/mining/steel mill country. Not to mention if you have a large country and goods require transport, and thus fuel.
Regardless, seems the US isn't terribly efficient with its energy. Ireland (a small, but kick ass island) manages to produce the same amount of GDP with 1/2 the energy. Of course, Iceland (another small island) requires 4 times the energy to produce an equivalent amount of GDP as Ireland.
Of course this all irrelevant as all good economists know what truly matters is which country is more proficient as producing attractive women per unit of energy. Alas, while Ireland may be more efficient at producing GDP per unit of energy, I'm torn between Ireland's ability to produce attractive women per unit of energy;
versus that of Iceland's;
This requires further study.