Earlier this year, social networking giant Facebook finished construction of its newest data center in Pineville, Oregon. In a press release, Facebook officials touted the new facility as "setting new standards for environmental responsibility in data center design and operations." Those standards incorporate renewable energy tactics such as rainwater reclamation, solar energy, and heat recycling.
By now, the energy-saving advantages of environmentally friendly efforts in IT are clear, even if companies don't always practice them. Even rather token efforts that make grossly inefficient data centers slightly less so can result in significant cost savings, given the escalating cost of electricity.
But it's clear that energy efficiency will become only more important in the years ahead. That's especially true for data centers, as the demand for IT horsepower increases. So what are the best next steps in efficient data center operation? And is there a place for renewable energy sources such as solar and wind in the current data center equation?
The common metric used in measuring the energy efficiency of a data center is a simple one: PUE (power usage efficiency) = total facility power/IT equipment power. The desired PUE number is 1.0, a one-to-one ratio between the energy being used to power the IT equipment and the total energy being expended in the data center facility. Unfortunately, most data centers operate at a PUE of about 2.0 at best, according to industry sources.
That's why vendors tout the PUE of their green compute technology. For instance, Hewlett-Packard claims its POD (performance-optimized data center) systems, which are self-contained high-end computing units, operate at a PUE of 1.2. That energy efficiency mainly comes from the systems' use of "innovative cooling techniques," says Jon Mormile, HP product marketing manager for POD. Keeping hot-running computer servers cool while they chug away is a major factor in the PUE discrepancy.
For its part, Facebook claims a PUE of 1.07 for the data center design it employed in its Pineville facility, a design it has made public in support of its "Open Compute Project." Unlike its Web 2.0 rival Google, which keeps its data center designs highly proprietary, Facebook launched its "open source" data center effort "to share our designs and collaborate with anyone interested in highly efficient server and data center designs," said Jonathan Heiliger, VP of technical operations at Facebook, in a statement.
Nonetheless, that impressive efficiency number does not include the energy Facebook is generating with it solar-panel array. That energy will be used to provide electricity to the office areas that support the data center, according to Facebook.
Which doesn't surprise Jack Pouchet, director of energy initiatives at Emerson Network Power, a division of multinational Emerson Electric. Because data centers are "energy dense" they're "not a perfect fit for solar," says Pouchet, who refers to himself as Emerson's "green guy." Renewable energy sources such as solar panels and wind turbines usually don't generate the volume of electricity needed to power a data center completely. They also come with inherent limitations, which include the requirement for generous amounts of sun and wind along with the space needed to set them up.