Which power saving techniques actually work?
Before you start implement energy efficient methods, it's worth thinking about whether they actually work. We've looked at 10 of the most popular energy efficiency myths and investigated whether they are true or not.
9. Going to DC power will inevitably save energy
Fact: Going to DC power entails removing the power supplies from a rack of servers or all the servers in a datacenter and consolidating the AC-DC power supply into a single unit for all the systems. Doing this may not actually be more efficient since you lose a lot of power over the even relatively small distances between the consolidated unit and the machines. New servers have 95 percent efficient power supplies, so any power savings you might have gotten by going DC is lost in the transmission process. Your savings will really depend on the relative efficiency of the power supplies in the servers you're buying as well as the one in the consolidated unit.
10. You're bound to save money by rushing out and buying the most energy-efficient equipment as soon as possible
Fact: Savings realised by more efficient equipment have to be balanced against the cost of running the existing equipment. Replacing £2,500 servers before their end of life to save £15 per year in power is not going to save money.
Instead, look for ways to implement energy-saving strategies that don't require new equipment or user buy-in. For example, applying a policy through Active Directory to shut down systems that aren't in use after business hours doesn't require buying new equipment and will save a lot of money. If you can get user buy-in, other actions such as powering off monitors, PCs, printers, and the like will save lots of power without buying anything.