If you're looking to green your data center and wondered what effect sourcing new components might have, The Green Grid has some details you should look at.The group's most recent whitepaper, Quantitative Efficiency Analysis of Power Distribution Configurations for Data Centers, found that replacing legacy components -- UPSs, DC rectifiers, power supplies, and the like -- makes a huge difference. In fact, configurations with newer components were found to be 25% more efficient than older set-ups.

One important point that must not be overlooked is that no single configuration provides the highest efficiency at every load, though "DC configurations prevail at low loads and AC configurations prevail at high loads," the report notes. Even then, the report notes, efficiency is only one standard by which to choose; there are others, such as cost and safety.

All this being said, The Green Grid researchers found:

• Power supplies are currently available that are approximately 20% more efficient than an average power supply of the past. • UPSs are currently available that are 7% to 8% more efficient than an average UPS of the past. • All the contemporary configurations it tested are approximately 25% more efficient than the legacy implementation of the 480Vac -- 208Vac system found in many data centers. Similarly, the contemporary double conversion implementation of the 480Vac -- 208Vac configuration is approximately 25% more efficient than the legacy implementation, "a difference that can only be attributed to component improvements." • The best known AC UPSs and DC rectifiers provide similar efficiencies, peaking at approximately 96%. • The end-to-end efficiencies of all of the contemporary implementations are generally within about 5% of each other at loads above 20%. • The efficiency differences among the contemporary implementations are relatively minor. All components and configurations have undergone great efficiency improvements in the last decade and will likely continue to improve.

Regardless of the topology, history shows that proper component selection is the dominant factor in delivering high efficiency, says The Green Grid. "Accordingly, when high efficiency is desired, great care should be exercised in the component selection process," the report concludes.