[1letterunixname]

It's too bad we can't run on LNG or H2 because of the improved energy / mass densities.

4 kcal/g: Carbs and protein

7: Ethanol

9: Fats and lipids

11: Gasoline

13: LNG

34: H2 *

* Hydrogen storage and distribution infrastructure is an exercise for the reader.

[WillAdams]

We do, sort of, just not very efficiently --- we burn up to 10 calories of petro-chemical energy in our industrial farming practices to get 1 calorie of food energy.