Sounds like the easiest thing in the world: Deploy lots of green technology like virtualization and low-power processing and then sit back and bask in fiscal and environmental glory.

Too bad nothing is ever that simple. As it turns out, going green is a lot more complicated than most people thought, particularly once you get past the most obvious solutions like consolidating servers and powering down idle components.

Take the storage farm. As Mario Apicella points out on his Storage Advisor blog, you could end up spending a bundle on high-capacity disk drives and shave 90 percent or more off the number of spindles per application, only to see the use of disk-to-disk backup or online warehousing jump through the roof. Tape backup is certainly easier on the energy bill too, but how easy is it really to devise a workable system to determine what, exactly, needs to be preserved in rapid-access disk storage?

Because enterprises are such organic creatures, the law of unintended consequences often kicks in whenever a cost-saving measure is introduced. Natasha Lomas, blogging on silicon.com, reports the tale of two firms that installed expensive videoconferencing systems with an eye toward lowering their travel budgets. The end result was that travel between home and branch offices declined while trips to Asia and Europe increased.

The good news is that since most enterprises were designed rather haphazardly over the years with little thought given to energy efficiency, there is still a lot of low-hanging fruit that can be plucked in the name of "green." Computerworld recently came out with its list of the "Five Quickest Returns on Your Green Investment," with consolidation, virtualization and data deduplication topping the technology initiatives.

Still, one of the major limiting factors in any green program is the lack of a clear set of standards to help executives better determine whether a given system or strategy is truly green. At the moment, a number of industry groups are pitching various standards and measurement practices, but as yet no movement toward a universal definition of "green." Research from the Digital Realty Trust indicates that a lack of common standards is already hampering the green movement in North America and could seriously jeopardize Europe's strong momentum.

Financial pressures are almost certain to bring about significant energy reduction in the data center over the next decade or so. The thing to keep in mind is that not all environmental measures are created equally. The job ahead is to determine which ones are truly effective and which ones only look good on paper.