Nobody likes high energy bills for their data center, but few can move their data center way north to Finland to use Arctic-cold seawater for cooling, like Google does at their Hamina Finland data center. But using some tricks from Google and others, companies can experience some data center savings through energy efficiency- by up to 50 percent.
Much of the energy in a data center goes to cooling, so focusing your attention on temperature pays big dividends. Google’s big tip here? Raise the thermostat to 80 degrees. Techs should be in shorts and t-shirts, not parkas, in your data center.
Two of Google’s temperature tips are about as low tech as you can get: plastic sheeting and sheet metal blanks. Hang sheeting wherever hot air must be contained, like hot aisles and around power distribution equipment. Use blanks to block gaps in racks to stop hot air from invading cold air spaces. Separation increases savings.
Four out of five data centers ignore their AC economizers, or don’t calibrate them properly. If you don’t use them, you’re “burning money” automatically. When you do use them, maintain accurate calibrations across all units. Make sure one unit isn’t reading high humidity while another is reading low levels, because the two units will compete with each other. Turning on and maximizing the use of AC economizers can save up to 30 percent of your cooling cost (all these are best case savings, of course).
Emerson, makers of many data center products, will happily share their Energy Logic approach with customers (or potential customers). Their research shows that saving 1 watt with proper server components cascades to saving 2.84 watts (or thereabouts) at the end of the chain. Lower power CPUs need about 10 percent less energy. High efficiency power supplies and voltage regulators save about 11 percent. Google adds another step to these tips by cutting out two AC/DC conversion stages by putting backup batteries in the storage racks with the servers they protect.
Power conversion from AC to DC happens far more times than most people realize in a data center, and each conversion steals some coins. Fans of DC-powered servers claim they save about 25 percent of the energy used by an AC server. Savings happen at the servers and by converting AC main feeds to DC in one giant power conversion unit instead of power supplies in each and every server.
Condensing servers onto fewer racks concentrates cooling and lowers cost. Emerson has a case study where they reduced 210 racks down to 60. That kind of savings is how you reach 50 percent drops in power usage.
Server virtualization may not lend itself to lower-power processor choices in the server, but can reduce your server count considerably. Most companies have delved into virtualization already. Those that keep pushing more software servers onto fewer physical servers with each refresh, and keep their eyes on these other savings tips, will continue to get more processing done with fewer watts each and every year.
James Gaskin writes books, articles, and jokes about technology, and consults for those who don’t read his books and articles. Email him at email@example.com.