"We are doing everything possible to be energy efficient at all of our data centers, says Wanger. "We separate cold air supply and warm air return." To get the heat away, says Wanger, "There is still no more-efficient means of moving energy than through water. Air as a liquid is much less dense and less efficient. Once we get that hot air, we dump it into a closed loop system and exchange it into an open-loop system, where we can remove the heat. We also use thermal storage. We can consume energy at night when it's sitting in the utility's inventory."
Also, says Wanger, "We have to put humidity into the air. The old way was to have a big metal halide lamp baking water. The humidification solution was to fire up a heat lamp and phase-transition it to humidity. Now we use a process called ultrasonic humidification, which uses high-frequency electronic signals to break water surface tension and dissipate cool water vapor into the air -- this takes about 1/50th the amount of energy."
The mod pod
For several years now, a growing number of vendors, like HP and Microsoft have been offering ready-to-compute data center modules that not only include compute, storage, but also cooling gear -- just plop (well, put gently) into place, and connect up power, connectivity, and whatever cooling is needed.
[ See also: Make mine modular: The rise of prefab data centers ]
Some don't even need a proper data center to house them in.
And it's not just vendors, either; hosting providers like i/o Data Center not only use their own modules, but also offer them directly to customers who might not be availing themselves of i/o's facilities.
For example, HP offers its Performance Optimized Datacenter 240a, a.k.a. "the HP EcoPOD." Amazon has its own Perdix container, and Microsoft offers its Data Center ITPAC (IT Pre-Assembled Components).
HP's EcoPOD uses free-air and DX (direct-expansion) cooling, without needing any chilled water. "Just add power and networking -- in any environment," says to John Gromala, director of product marketing, Modular Systems, Industry Standard Servers and Software, HP. According to Gromala, "the EcoPOD optimizes efficiency achieving near-perfect Power Usage Effectiveness (PUE) between 1.05 to 1.30 (depending on ambient conditions)." And, says Gromala, "because EcoPODs are freestanding, they can be deployed in as quickly as three months. Customers are putting EcoPODs behind their existing facilities, inside warehouses or on roofs."
Switching from AC to DC
IT gear runs on DC (direct current), but utilities provide electricity as AC (alternating current).
Normally, "A UPS converts the 3-phase 480vAC coming from the power utility to DC, to charge its batteries, and then reconverts back to 3-phase 480vAC to send it through the data center. The PDU (Power Distribution Unit) for each rack or row of racks converts the 3-phase 480vAC to 3-phase 208vAC, which is what normally goes into IT gear like servers and storage arrays. And the power supplies in the IT gear converts that 208vAC into 380vDC," says Dennis Symanski, Senior Project Manager, Electric Power Research Institute, and chairman of the EMerge Alliance's committee writing the 380vDC standard.