Google seeks machines with highly efficient components such as power supplies. "Our servers only lose a little over 15 percent of the electricity they pull from the wall during these power conversion steps, less than half of what is lost in a 'typical' server. Similarly, our motherboards use very efficient voltage regulator modules, maximizing the amount of electricity delivered to the components that do work."
The company says the efficient power conversion saves it an estimated 500 kWh per server per year compared to a typical system.
Google also flexes its power as a mass buyer of hardware. "We encourage all of our suppliers to produce components that operate efficiently whether they are idle, operating at full capacity, or at lower usage levels," the company reports. "Our published studies indicate that more energy proportional systems could cut in half the total energy used by large datacenter operations."
3. Strip out the superfluous server parts. Google reports that it omits unnecessary server and rack parts from its systems, such as graphics cards -- and even excess fans. Those tweaks save on wattage. "Moreover the fans are controlled to spin only as fast as necessary to keep the server temperature below a threshold," Google reports.
4. Use free cooling. Google equips its datacenters with cooling towers to inexpensively keep them at an optimal temperature. The approach (pictured below) essentially uses water evaporation to cool the facilities, which means the company doesn't need to turn on its energy-draining chillers as often. That's a big power saver, which translates to a big money saver. [ Learn about Intel's successful experiment with so-called free cooling by reading "Intel pushes the limits of free cooling to 90 degrees." ]
5. Manage airflow. Among the other nuggets of advice Google offers for running a more efficient datacenter, the company suggests this: "Good airflow management is a fundamental to efficient datacenter operation. Start with minimizing hot and cold air mixing and eliminate hot spots."
[ Learn more about creating hot and cold aisles and other tips to make your datacenter more energy efficient by reading "Savor the fruit of others' green IT success." ]
6. Don't be afraid of a little heat. "Raising the cold aisle temperature will minimize chiller energy use. Don't try to run at 70 [degrees Fahrenheit] in the cold aisle, try to run at 80F; virtually all equipment manufacturers allow this," Google recommends.
[ Learn more techniques for keeping datacenters cool by reading "Beat the datacenter heat, cheap." ]
You can learn more about Google's sustainability practices at its corporate Web site.