Making your data center more energy efficient begins with these five basics, says John Engates, CTO of Rackspace, an IT hosting company.

 Commission a professional audit, at the data center and hardware level. Companies such as Dell, HP, Intel and Sun provide these data center auditing services. Data center design used to be more rule of thumb, but today it is a science. Auditors will professionally assess the design of your data center including the hot and cold row layout. Auditors will help you place your data center employees in the most energy-efficient setting —typically not in the actual data center server room. This helps increase density and utilization of the HVAC system. Auditors also will assess inventory, recommending the older hardware be replaced for newer, more energy-efficient hardware or even for virtualization where possible.

 If you don't have the budget to commission an auditor, on your own evaluate your server processors. Make sure you're running lower-power multicore processors if you want to see a significant difference in energy usage.

 Virtualize wherever possible. If you have servers that are running underutilized, then try combining those by splicing up one server with virtual software. This will increase energy efficiency and data center space.

 Review the data center's electricity bill. Many IT and data center managers never see the electricity bill for their companies. Today, this is a mistake. IT and data centers contribute greatly to electricity usage, therefore it is in the business' best interest to monitor IT's energy consumption closely. This is a key route to measuring energy efficiency and can be used for benchmarking as you work to improve consumption.

 Work with your local utility company to use alternative energy. For instance, Rackspace's new data center in London operates fully on renewable energy through Slough Heat & Power. Other utility companies have similar offerings and many providers even offer programs to give consumers credit for virtualizing their IT infrastructure.