AC and DC Battle For Data Center Efficiency Crown

jfruh writes "AC beat DC in the War of the Currents that raged in the late 19th century, which means that most modern data centers today run on AC power. But as cloud computing demands and rising energy prices force providers to squeeze every ounce of efficiency out of their data centers, DC is getting another look."

Comments

Makes sense.

[Anonymous Coward]

AC is better than DC for transporting electricity because you can convert between voltages with just a transformer. But in a data centre, when all the equipment will be powered by the same voltage, it makes sense to use one good efficient power supply for multiple computers, so that all the components don't have to be duplicated for each computer.

Re:Makes sense.

[effigiate]

One of the challenges of HVDC, especially in the transmission/distribution world, is that normal switching happens on the line and not at the breaker. If you can switch futher down the line, you can leave all the people closer to the breaker with power. The issue is that this switching happens while current is flowing which requires that the device interrupts real current. In the AC system this is relatively easy because the arc created by opening a high voltage circuit under load goes out at every current zero. There is no current zero on DC, so you force the interrupting device to break current. An similar situation can be seen if you look at relay contacts. They may be rated at 20A @120VAC but only 0.5A at 12VDC.