two nations with the same energy consumption. one is more efficient than the other, and this it's wealthier than the other.

two nations, one four times more efficient but uses half of the energy consumption of the other country. that one is wealthier although it uses less energy.

qed 

 I don't disagree. Wealth depends on the how the energy is applied. Several variables can impact this.

The running a bunch of stoves for no purpose versus running the same stoves to sell cooked meals.

But less energy is not necessarily the same as low energy.