OAKLAND, CA — While the core concepts of greener IT are fairly easy to understand, the trick is in how they are implemented. Plenty of companies now practice energy efficient computing, e-waste recycling, virtual conferencing and more, but some efforts rise above others.

In its fourth annual Green 15 list, InfoWorld calls out companies, schools and governments that are taking big strides in reducing IT's impact. The list shows that green IT isn't restricted to tech firm like Intel and Fujitsu, but is also being embraced by the likes of FedEx, construction company Hovnanian and health insurance provider Aetna.

"Virtualization, PC power management, videoconferencing, paperless solutions, e-waste management, and data center efficiency technologies are once again at the center of these exemplary IT initiatives," Ted Samson, InfoWorld senior analyst writes. "But one striking difference about this year's batch should be noted: A wealth of third-party products and services has emerged to help companies jump-start green IT projects...That's good news for organizations that don't have the internal technical know-how to build such systems themselves."

FedEx got a nod for changes to its Colorado Springs, Colo., data center that condensed the work of 4,000 servers into 400. The center also uses two heat exchangers that provide thousands of hours of free cooling from the dry, cool climate outside.

Fujitsu, Hovnanian and data center operator Xiolink also landed on the list due to data center projects, such as Hovnanian's virtualization of servers, storage and employee desktops.

Others like Aetna and the Copernicus Group Independent Review Board were recognized for using IT to cut down on how much paper they use, in turn slashing energy and costs while increasing work efficiency. Aetna started using electronics contracts and the Copernicus Group created a document-management system that has saved more than $2 million.

Autodesk, meanwhile, implemented teleconference and video chat systems to reduce travel while improving communication among employees. Replacing physical meetings with virtual ones has gained attention not only due to the emissions they save, but also saved time and costs.

Another growing trend we've seen is big companies turning an eye to the numerous computers they oversee to cut out wasted energy. The Boulder Valley School District, West Virginia Office of Technology and Fairfax County, Va., each found their way onto the Green 15 by implementing power management systems that better control when unused computers — each has over 10,000 in their systems — get turned off.

The full Green 15 list includes:

• Aetna
• Autodesk
• Boulder Valley School District
• The Copernicus Group Independent Review Board
• Fairfax County Government
• FedEx
• Fujitsu
• GE Energy
• HCL Technologies
• Hovnanian
• Intel
• Tata Consultancy Services
• Telenor Norway
• West Virginia Office of Technology
• Xiolink

_{Virtual meeting - CC license by ShashiBellamkonda/Flickr}