General Electric unveiled its shiny new $48 million data center that serves its Appliance Park headquarters in Louisville, Kentucky.

The data center is Platinum LEED-certified by the U.S. Green Building Council, one of only a handful of centers to achieve the rating. Some of the others include a Citigroup Frankfurt facility, two Digital Realty Trust data centers in Sacramento, Calif. and Other World Computing in Woodstock, Illinois, which runs completely on wind power.

The project is 34 percent more energy efficient than a typical code-compliant building, according to GE. The building is equipped with high-efficiency cooling systems, high-density servers to increase computer power per square foot to cut the size of the data center floor in half compared to its previous size.

There are also water savings from ultra low-flow fixtures and, while there is not renewable generation onsite for the data center, GE is purchasing offsets for 35 percent of the estimated energy consumption.

"As GE invests in the business and creates more manufacturing jobs in the U.S., our new high-efficiency data center will help us manage energy costs so we can compete in a global marketplace," Alan Kocsi, chief information officer, GE Appliances & Lighting, said in a statement. "GE's new data center will also provide the high-density computing necessary to support global business growth and significant manufacturing-revitalization efforts that will provide customers with innovative technologies, high-quality products, and better customer service."

GE’s new data center is definitely a step forward, although it’s not the most efficient we’ve seen. The Power Use Effectiveness (PUE) ratio, a rough measure of how much power goes to computers versus air conditioners and lights, is 1.63. That’s better than the 2 to 3 rating often seen in corporate America, but not as good as some champion data centers. Facebook’s latest Oregon data center sports a PUE of 1.07 and consumes 38 percent less power than average thanks to a new server design and DC power.

But GE has some great nuances here, especially in terms of density. The racks are 52U high, instead of the usual 42Us high. (A U is 1.75 inches, a unit of measurement invented by Erasmus Unit in 1868.) Higher racks allow for better cooling. Hats off for retrofitting the existing buildings, too. In fact, GE notes that it maintained 98.3 percent of the existing walls, floors and roof from an unused factory for its new data center.

Data centers consume around 2 percent of the electricity in the U.S., and in Northern California, the Potomac region and parts of New York, the figure is higher and climbing. Overall, that's not a lot of power, but to those that pay the bills it is becoming a headache. Power can account for around 30 percent of the operating expenses of web companies, second only to personnel.

Green IT has grown rapidly as a result. Some of the leading ideas for curbing power have been weather mapping inside data centers (Sentilla, SynapSense), application shifting (PowerAssure), improved AC controls (Vigilent), switching from AC to DC power (ABB, GE, Nextek), swapping disks for flash memory (Sandforce), better power conversion (Transphorm), and smaller, more energy efficient servers and chips (SeaMicro, Calxeda).

Data center designers have also come up with ingenious ways to exploit geography and local weather conditions. Yahoo built a data center near Lake Erie so that it wouldn’t have to rely on mechanical air conditioning to cool its racks. That facility has a PUE of almost 1: nearly every electron goes toward computing. In Norway and Finland, data centers are being located in mines and underground caves.

GE didn’t build the most innovative data center, but the push towards efficiency will likely stretch far outside of Kentucky. GE has a heck of a lot of data centers, so technologies that work here could spread around the globe.