"the Sony PS4 and Microsoft Xbox One consume two to three times more annual energy than the most recent models of their predecessors".
I used to work for one of the platform manufacturer mentionned above.
It is normal a new model consume les than their MOST RECENT PREDECESSORS, because when the PS3/Xbox360/Wii were launched, it represented the best of the technology Sony/Microsoft/Nintendo could offer at the time.
Then, for each iteration, sometimes sublte that you don't see or see (like a slim version), the manufacturer scrap whatever they can from the hardware.
Reducing the number of transistors reduces cpu (or others) yields at manufacturing, but it also reduces how much heat you need to dissipate, therefore the fan, therefore the size, therefore the packaging, so you can ship more in an airplane, etc.
It's not really something you should compare if you wanted to be fair.