An alternative approach to conventional alternating-current (AC) power uses a direct-current (DC) power distribution scheme throughout a data center. Most data center server racks are not currently powered this way, but with the advent of servers on the market that can operate with either AC or DC, it is possible to use the DC powering approach, thus eliminating extra power conversion steps and losses. Other benefits include reduced cooling needs, higher equipment densities, and reduced heat-related failures.
This web site describes two pioneering demonstrations - one where direct current is distributed at the facility level to racks of computers that have been modified to directly accept high voltage direct current (DC) and another where the DC power conversion occurs at the rack level and DC is then directly distributed to servers within the rack. In typical data centers, the loss in electrical power through conversions of alternating current (AC) to DC to AC to DC occurs for all power flowing to the IT equipment. Efficiency gains have a magnifying effect by reducing need for HVAC (e.g. 10% saving at the UPS level mean about 10% energy savings for the entire data center, compared to a very efficient AC baseline case and assuming the HVAC system consumes as much power as the IT equipment). Source: Lawrence Berkeley National Laboratory .
A New Study Reinforces Case For DC Power Saving
It’s been five years since a study by Lawrence Berkeley National Labs outlined the potential for DC power distribution to cut data center energy use by 10 to 20 percent. But adoption of DC in data centers remains limited, even as the industry aggressively pursues a wide array of other energy savings strategies.
