The chips inside our servers all natively use DC power. Inside the box, a rectifier turns AC into the direct current which the silicon wants. The majority of racks in the world still have AC power strips or "power distribution units," but there's a head of steam for DC distribution.

Environmentally-conscious data centers are re-examining efficiency, and a lot of new power sources such as fuel cells inherently provide DC power despite DC being seen by many as unsafe.

In this supplement we take a closer look at:

• The widespread use of DC power in data centers and why organizations are using it
• Why it might make sense to store energy in the racks, instead of in the UPS
• The second coming of DC distribution
• How superconductors could improve the efficiency of electrical distribution