You won't find solar, wind, or hydrogen power in the bag of tricks presented here. These alternative energy sources require considerable investment in advanced technologies, which delays cost savings too much for the current financial crisis. By contrast, none of the following eight techniques requires any technology more complex than fans, ducts, and tubing.
The eight methods are:
Radical energy savings method 1: Crank up the heat The simplest path to power savings is one you can implement this afternoon: Turn up the data center thermostat. Conventional wisdom calls for data center temperatures of 68 degrees Fahrenheit or below, the logic being that these temperatures extend equipment life and give you more time to react in the event of a cooling system failure.
Experience does show that server component failures, particularly for hard disks, do increase with higher operating temperatures. But in recent years, IT economics crossed an important threshold: Server operating costs now generally exceed acquisition costs. This may make hardware preservation a lower priority than cutting operating costs.
At last year's GreenNet conference, Google energy czar Bill Weihl cited Google's experience with raising data center temperatures, stating that 80 degrees Fahrenheit can be safely used as a new setpoint, provided a simple prerequisite is met in your data center: separating hot- and cold-air flows as much as possible, using curtains or solid barriers if needed.
Although 80 degrees Fahrenheit is a "safe" temperature upgrade, Microsoft's experience shows you could go higher. Its Dublin, Ireland, data center operates in "chiller-less" mode, using free outside-air cooling, with server inlet temperatures as high as 95 degrees Fahrenheit. But note there is a point of diminishing returns as you raise the temperature, owing to the higher server fan velocities needed that themselves increase power consumption.
Radical energy savings method 2: Power down servers that aren't in use Virtualization has revealed the energy saving advantages of spinning down unused processors, disks, and memory. So why not power off entire servers? Is the increased "business agility" of keeping servers ever ready worth the cost of the excess power they consume? If you can find instances where servers can be powered down, you can achieve the lowest power usage of all -- zero -- at least for those servers. But you'll have to counter the objections of naysayers first.