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.