Good Incentives Boost Data-center Energy Efficiency
A Microsoft executive shared techniques the company has used, including new kinds of employee incentive programs and internally created automation tools, to reduce the energy consumption of its growing data centers.
The methods he described could help other companies that use or operate data centers reduce costs, said experts who also spoke at the data-center efficiency strategy conference put on by the U.S. Department of Energy and the Environmental Protection Agency in Redmond, Washington, on Tuesday.
While there are plenty of technology solutions for improving data-center energy efficiency, not many companies are using them, said Christian Belady, principal power and cooling architect at Microsoft. "It boils down to a behavioral problem, not necessarily a technology problem," he said.
Microsoft decided to change the incentives for workers as a way to encourage them to use the most energy-efficient techniques. Traditionally, the various business groups within the company were charged for using the company's data centers based on the amount of floor space required to stack the servers that their services used. That spurred a drive within the business units to minimize the space they used, often through the use of extremely dense servers. Those servers, however, sucked power and required more cooling, Belady said.
Now, Microsoft charges business units based on the amount of energy consumed by the servers that host their services. "We moved from cost as a function of space to cost being a function of power," he said.
That shift made individual business units conscious of the number of DIMMs (dual in-line memory modules) they had at their disposal, for example. "Now those DIMMs are costing you power, and you're getting a year-over-year chargeback for those DIMMs," he said. Such charges make the business units less likely to require more memory then their services actually need, he said.
Doing away with underutilized equipment can result in major savings. "Usually around 30 percent of servers in a data center can be turned off," said Ken Brill, founder and executive director of the Uptime Institute. Plus, getting rid of underutilized equipment, including unused servers put in place as backup in case others fail, can also save money and energy.
"Until it's demanded and bonuses are paid on it, it's not going to happen," he said. "Yet, that's the single biggest thing we could do that would have the biggest impact" on energy efficiency.
The effort to save on energy at Microsoft even goes as far as the code that developers write, Belady said. A developer may write new code that could speed up very slightly the time it takes for a service to respond to an end-user. Now, the developer will consider how much computing power and thus energy in the data center that code will require. If it's a lot, the developer may decide to forgo the slight bit of extra speed to save on the energy cost, Belady said.
Figuring out ways to code that can save energy isn't a technique that's widely shared across the industry. One event attendee asked Belady if he knew of any resources where she could learn more about the relationship between code and power usage, but he didn't have any suggestions to offer.
Other data-center operators have also made the shift to quantifying usage based on energy rather than space. Around two years ago, 365 Main, a hosting company, began charging customers based on killowatts instead of rack space, said Miles Kelly, vice president of marketing and strategy at 365 Main.
Microsoft has also looked at the incentives for data-center facilities managers and changed the way they are paid. Their yearly bonuses are based on year-over-year efficiency improvements, Belady said. "As a result, the behavior of our guys has changed," he said.
One data-center manager decided he wanted to clean the roof of the facility so that it could reflect heat better. He detected better energy efficiency as a result, and now the company keeps all its data center roofs clean. "That's one example of many of how we've improved," Belady said.
Incentives are also changing at utility companies in ways that can benefit enterprises. "As a facility manager my incentive isn't to sell you more electricity, but to give you the tools to be more efficient," said Francois Rongere, segment supervisor with PG&E's high technology energy-efficiency team. "My bonus is based on how much savings you have done in my territory."
Those energy savings often translate into real money from the utility. Ray Pfeifer, who works with the Silicon Valley Leadership Group, was recently involved in a series of experiments with companies to try to quantify how certain changes to their data centers affected energy usage. He said that many of the implementations were 100 percent funded by utilities, which often offer incentives to companies for investments that can cut their energy usage.
While that may be good news to the enterprise, the utility incentives only show how behind the curve businesses are in general, said Brill. "It's appalling to me that we have to have utilities offering incentives to do what's good business sense," he said.
Key to all of the improvements at Microsoft is having good measurement data, because efficiency has to be compared before and after operational changes to determine if there will be positive results. Microsoft developed a software tool internally that tracks power usage of its data centers on a daily basis. The tool shows the outside temperature at the center, its carbon emissions and how much power each individual server consumes.
Before Microsoft developed the tool, a worker would walk around the data center writing down metrics about the servers and conditions at the center, Belady said. "He was wearing out his shoes," he said. "We had to automate, there's no question about it. Our whole goal is to minimize how many people have to be in a data center."
Other companies looking for a similar type of measurement tool may soon get one. The U.S. Department of Energy is developing the DC Pro tool, software that measures data-center efficiency. Some users began beta testing the tool about a month ago, with the public availability of the first version scheduled for September, said Paul Scheihing, a technology manager with the department's industrial technologies program.
All of Microsoft's efforts have paid off, Belady said. From 2004 to 2007, Microsoft saw a 22 percent improvement in the energy efficiency of its data centers, he said.