At least in the field of computing, this is the engineering holy grail of our time:
...if you were an analog alien floating around in some kind of off-the-grid Galactica you might look down at one of our data centers and see 4MW going in and a mere few hundred watts coming out through an OC-48 fiber trunk and wonder "what the hell?" Watching it spew entropic HVAC waste heat, those bemused aliens could be forgiven for concluding that that these buildings with no obvious use must be massive sacrificial alters where silly humans offer up electricity and make their wishes or say their prayers (well, perhaps we do).
...given that a data center is really just a vast state machine, it would be really cool if its efficiency was tied to some kind of intrinsic cost of state transition rather than to trillions of leaky circuits. After all, cars burn a lot of gas, but the energy they use is at least in the ball park (an order of magnitude or so) of the intrinsic cost of moving their mass against friction and pushing air out of the way. But for data centers the real intrinsic cost is probably damn near zero, we're ultimately only processing information after all. So, all those megawatts are tied instead to the massive current leakage associated with the fact that we choose to maintain state in silicon instead of something more elegant (but currently impossible). Viewed as a physical system, data centers are about as efficient as a well cooled warehouse full of burning light bulbs