Two quick ways to gain a return on investment through greening the data center are obvious, yet often overlooked: replacing less-than-stellar power supplies and sharing information technology.
Energy is lost where you least suspect it. Each time energy — in the case of data centers, electricity to power computers — moves from Point A to Point B, the total throughput diminishes. That includes power generated at coal-fired plants as it moves across transmission grids and through local distribution lines. It also means that electricity that comes from the wall socket is decreased as it moves from the wall to an uninterruptible power supply, to a power distribution unit and then to the IT equipment in the data center’s racks.
To reduce energy loss, each component in the power-delivery chain must be as efficient as possible. A good place to start is the power supply devices. Power supplies typically garner efficiency ratings of 50 percent to 60 percent, which means that up to half of the energy entering the unit goes unused when powering intended servers and other devices.
80 Plus, an energy-saving incentive program funded by electric utilities, rates the power efficiency of power supplies. As the name implies, one of the group’s goals is to identify power supplies that have an energy efficiency rating of at least 80 percent. To date, the Portland, Ore.-based program has certified more than 550 power supplies that meet that rating. For a desktop PC, the benefit of using such a high-efficiency power supply would add up to direct savings of 85 kilowatt hours per PC per year.
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300 kwh per server Annual energy savings possible from using power supplies that push at least 80 percent of electricity through to the server
30% by 2015 The federal energy reduction goal for all federal agencies, relative to each agency’s 2005 baseline energy consumption
SOURCE: Executive Order 13423
Although simple in theory, sharing resources often proves to be one of the most difficult eco-exercises in practice. This includes sharing power sources, data storage and cooling.
For example, if two data centers can consolidate storage devices at one location, less power will be used for lighting and heating the building. And if the number of storage devices can be reduced, so too can the electrical load needed to operate the devices and accompanying cooling equipment.
Ironically, server and storage consolidation ultimately may require more flexibility, as higher-density processing is crammed into smaller spaces and data centers reach maximum power and cooling capacity. Storage vendor EMC faced this problem in 2007 at its Westborough, Mass., data center, says Kem Clawson, chief technology officer for the company’s federal division. Rather than expanding the facility, it off-loaded data slated for tape backup to another EMC facility that had excess cooling capacity.
In the government, though, this can be a challenge, says Ken Salaets, director of technology and trade policy for the Information Technology Industry Council in Washington, D.C. “Let’s look at one building in one agency: You can modernize and virtualize, assuming you have everyone on board,” he says. “Now, if you have the agency which has seven centers, you can still create an integrated process. But the odds are you have different energy sources for some of them. So, to create a policy and management approach is really a challenge. Now, apply that to the larger government.”