Should Servers Come With Batteries?

Will the data center of the future have no central UPS units, and be filled with servers with on-board batteries? The data center team at Facebook believes it should, and is pledging to share its best practices - and perhaps wield some of its clout with vendors and data center operators - as it presses its case for change.   

Facebook recently disclosed its plans to adopt a novel power distribution design pioneered by Google that removes uninterruptible power supply (UPS) and power distribution units (PDUs) from the data center. The new design shifts the UPS and battery backup functions from the data center into the cabinet by adding a 12 volt battery to each server power supply.

While many best practices shared by Google, Microsoft and Facebook can help other data center operators save energy and money, other customizations are impractical.   

Big Companies, Big Innovation 
"A lot of the innovation in the field is being driven by companies with thousands of servers who really care about the efficiency of these things," said Facebook's Amir Michael, who previously worked on Google's data center team. "We have capital to be able to afford engineers to solve these problems. It's not really benefiting the rest of the industry. Smaller companies who might deploy fewer servers can't go and design their own systems."

In discussing Facebook's plans for on-board batteries, Michael discussed ways these innovations might become more widely available.

"It's a chicken and the egg problem," said Michael. "No one really makes a data center without a UPS, and no one makes server with a battery on board. Server manufacturers aren't going to build a server with a battery on board, because no one has a place to deploy that."

Facebook's buying power gives it some influence with hardware vendors. Michael noted that Facebook is working with vendors on power supply customizations, and has gotten little pushback from server vendors on its modifications to motherboards.

"Volumes are large enough that server vendors are helping us with that rather than opposing us," he said. "We're actually being supported quite well."

Not all equipment vendors would endorse an industry shift to servers with on-board batteries, however. Makers of UPS equipment and power distribution units (PDUs) are significant players in discussions of industry best practices, and would be unlikely to advocate designs that reduce demand for those products.

Is there a transition that could lead to more options for innovation in power distribution? Michael suggested potential changes in wholesale data center leasing models.

"One example could be to build a data center where you have a portion that has no UPS," he said. "The data center operator can charge customers a lower rate to deploy their servers in a part of the facility that doesn't have a UPS. The customer, if they're savvy, can go and purchase a server which has a battery on board. They'll pay a little more up front, but in the long run they'll save money because they're paying less to operate that server over a period of time.

"We hope to see the industry move to a model like this," said Michael. "As a customer that leases space in data centers, I would welcome a change like this."

Facebook is one of the largest customers in the market for turn-key data center space, and leases space from leading providers like Digital Realty Trust, DuPont Fabros Technology and Fortune Data Centers. 

Are these cutting-edge energy efficiency strategies only appropriate for large-scale operations like Google and Facebook? Or would enterprises and smaller companies adopt these practices if they had access to them? Facebook says it will be more active in the growing industry conversation about best practices, which it hopes will reveal the answer.  

"It's no longer okay just to be secretive," said Michael. "There's too much at stake.  Smaller companies might use too much of their resources and too much of their capital on their data center infrastructure. They should be allowed to benefit from the same type of optimizations that we're making here at Facebook."