Data center efficiency has made great strides in the past few years, driven both by the oil shocks earlier in the decade and the rapid rise of virtualization and other hardware consolidation technology that swept the IT industry.

So when we see surveys like the recent one from Kelton Research that indicate nearly 15 percent of active servers are not performing any useful function, there is reason for both hope and despair. The hope side of the equation comes from the fact that even five years ago, that number probably would have been 50 percent or more. But then the realization hits that the 15 percent of servers represents about $25 billion in wasted energy, and it's obvious that we still have a way to go on the energy-efficiency front.

Of course, capitalism being what it is, there is no shortage of new power management solutions waiting in the wings, confident that despite the rise and fall of eco-friendly trends over the years, saving money never goes out of style. The trick is to convince enterprises that even in times of relatively cheap energy, significant improvements to the bottom line can still be had by expanding the focus of normal system refresh cycles to include an energy-efficiency component.

One potential growth area is in power management software systems for the data center. Newcomer Viridity Software is looking to tap into this vein through a series of systems and services aimed at energy management and asset optimization. The company aims to unite energy-saving efforts across the application and hardware layers, bringing under one roof the often conflicting efforts of IT management, facilities management and executive-level oversight.

Another fresh face is nlyte Software, which recently unveiled a new version of the Data Center Performance Management system that combines asset discovery and workflow management to optimize resources by consolidating IT activity onto as few systems as possible. The package also includes an advanced modeling module that helps gauge the impact of changes to infrastructure, cooling and space, both from an energy and operational perspective.

Theoretical modeling is all well and good, but somewhere along the line you need to know what your actual consumption is. A New Jersey company called Raritan hopes to address that need with a series of inline power meters that can be deployed throughout the data center to monitor energy usage on the rack- or equipment-level. The Dominion PX-3000 can be outfitted on the company's power distribution units (PDUs) or affixed to standalone devices like network switches, storage arrays and mainframes. The unit gathers such data as voltage, current, active power and kilowatt hours, and can be outfitted with optional sensors to monitor temperature and humidity conditions as well. Data is viewed on a remote GUI and is compatible with Raritan's Power IQ energy management software.

It would be easy for most data center managers to point to the efficiency gains of the past few years and conclude that the job has been done. But the fact is that waste and inefficiency can never be fully eradicated, and what once seemed like a satisfactory environment can quickly become a leaking ship as new technologies come on the market.

So even if you have seen tremendous savings through virtualization and outsourcing over the past few years, you at least owe it to yourself to find out what is and is not working in your own environment.