Energy consumption of data centers is clearly a problem.  As a forthcoming article in Building Operating Management points out, the energy consumed by data centers has doubled since 2000. It's projected to double again by 2011, if the current trends continue, according to the EPA.  

The projects are contained in a recent report released by the EPA on data center energy efficiency. The massive study includes a wealth of information on current data center operations. The bottom line: data centers need to be constructed — and operated — in a more efficient manner.

Virtualization is one way to make major efficiency gains. Reducing the number of servers in a data center also reduces the heat load, which reduces cooling costs.

A controversial way to improve energy efficiency is to use an air economizer. Using outside air in some regions can dramatically slash cooling costs.

For now though, fear seems to outweigh the benefits. Data center operators are afraid that outside air will introduce contaminants into the data center, reducing the life expectancy of servers. Lawrence Berkley Labs has conducted a study on the issue. Their findings? Outside air isn't as harmful as previously thought.

Of course using outside air isn't a magic bullet. It requires a more sophisticated control system. And one expert I interviewed pointed out that if outside air has to be dehumidified, it could lead to an increase in energy use. So the system has to be calibrated to only use outside air when the conditions are appropriate.

Still, for those willing to consider bucking conventional wisdom, it's clear the strategy has the potential to generate handsome rewards. At this point, the question is: How much higher will energy costs have to go before such a strategy gets serious attention?