According to a report from the Environmental Protection Agency ( EPA), U.S. corporations are moving toward virtualization at least in part due to concerns over their power consumption.

X86-based servers consumed 68 percent of the electricity used by IT equipment in data centers during 2006, but run at processor-utilization rates of between 5 and 15 percent, according to the EPA's report on the efficiency of corporate data centers.

It may not be the only reason, but two companies that have been able to increase their utilization, cut power consumption and save money on both hardware and support, say worries about electricity did help move them into the virtual world.

BancMidwest Services, a subsidiary of Mainstreet Bank in St. Paul, Minn., used VMware ESX Server to consolidate three servers into one, according to BancMidwest IT manager Brian Priebe. The server is connected to a Compellent Storage Center storage area network (SAN), which stores the virtual machine images for the host computers.

"To take in server virtualization on our side, we are able to expand our data center without expanding the physical footprint of the data center, which is key for a small business," says Priebe. "We're not increasing our power and cooling costs."

Priebe says he'll probably virtualize and eliminate another five to six physical servers and save both the floor space and electrical consumption they take. Priebe is able to quantify his energy consumption with the use of tools from Compellent that monitor the virtualized servers.

"We were able to separate all our applications and bring them into their own VMs," says Priebe. "We were then able to monitor the virtualized servers with our Compellent chargeback and storage resource management tools and look at and associate what the cost of a virtual machine was, how much disk space it was taking up, and then charge back its use to the appropriate organization."

"As we take on those applications we can say no more power costs, no more cooling costs-we use the term 'reduce, re-use and re-silo'-reduce the physical, re-use the servers for a test environment," says Priebe.

Power problems-the kind that turn the lights out unexpectedly, not power-use issues-drove Los Angeles-based Ares Management toward virtualization, says Ping Ooi, the investment company's associate VP of technology.

More to test the waters than migrate anything, Ares virtualized a Blackberry server in its Los Angeles office, and replicated it to New York. When the machine in LA went down "we brought up the server in New York and no one was the wiser," he says.

"Then, in November, one of our main breakers blew," Ooi says. "I had to run down to the office and spend several hours bringing every server back up. The problem with that is, if the breaker blows and you bring everything back up, you bring it back up to where it was when the breaker blew-if I was drawing 15.5 AMPs and I brought it back up, the breaker would blow again."

By virtualizing 10 physical servers, Ooi reduced his energy consumption by 25 percent.

As a result of the early virtualization project, Ooi has now consolidated 49 physical servers onto just five and has been able to avoid buying and supporting 39 new servers.

"Servers start at [US]$2,000 to $8,000," Ooi says. "That's a lot of money. We've been able to put a lot of applications into play that we couldn't have done before-I would have had to tell my users to wait 6-8 months until I built a data center to make that happen. With virtualization, we had things in a couple of days."