Managed hosting company Rackspace is going green. The company's new data centers in the United States will be built with a focus on energy efficiency.

The last time San Antonio-based Rackspace built a data center in the United States from scratch was about seven years ago. The company's other U.S. data centers came mostly through acquisitions, especially purchases from failed companies after the dot-com bust, Rackspace CTO John Engates said in an interview.

But the company has two new data center projects under way in the United States, and a third is being planned. The centers will be equipped with an eye toward more energy-efficient servers, hard drives, and processors, he said. "Our next 500 servers will gain from AMD and Intel's next generation of multicore processors," he says. "In the past, when data centers were built, they were giant warehouses with lots of air conditioning pumped in," he says. That's changing -- power consumption is top of mind today, he said.

Much of the company's new corporate-wide GreenSpace initiative is being driven by the environmental awareness in the United Kingdom, where Rackspace also operates data centers for European managed hosting services customers. The United Kingdom has stricter environmental regulations than the United States, so that's creating "competition between the U.S. and the U.K." when it comes to green awareness, he says. In the United Kingdom, Rackspace is buying energy to power its data centers from a company that uses renewable power sources, including power that's fueled by "green" wood chips made from byproducts of recycled materials, he said.

Those kinds of green power sources are lacking in availability in the United States, Engates said. In light of that, Rackspace has launched a program to invest in the renewable energy projects of NativeEnergy to help offset carbon emissions created by servers in Rackspace's U.S. data centers.

Rackspace adds about 430 servers per month to its U.S. data centers, so the company plans to offset that carbon emission by investing in NativeEnergy's renewable energy projects, including wind farms in South Dakota and a dairy farm that's powered by methane, Engates said. NativeEnergy helps build Native American, farmer-owned, community-based renewable energy projects.

Last week Rackspace also sponsored a Green Day for employees, helping to build awareness about what they can do on a personal level to become more environmentally friendly. Rackspace employees were able to test-drive hybrid automobiles and ride Segway scooters.