Microsoft says this new cooling method could enable more powerful chips and efficient data centers by Justine Calma

With microfluidic cooling, liquid flows through channels etched onto the back of a chip. The trick is making sure the channels, about the width of a human hair, are deep enough to prevent clogging but not so deep that the chip becomes more likely to break.

Two things here -

1. Since the coolant does not need to cool the metal stuck to the chip, it does not need to be as colder. So less energy.
2. During spike in demands, you could overclock, instead of scale so less machines, possibly.