In my ongoing exploration of Green IT strategies and solutions, I came across APPA (the American Public Power Association) fact sheet on virtualization, power management and other strategies that can create big energy savings for organizations. According to the APPA website, electricity demand for data storage doubled between 2000 & 2005 and is likely to double again by 2010. PG & E sites an interesting factoid — a single rack filled with high-density servers emits as much CO2 in its energy use as 285 cars driving across the country.

PG & E (Pacific Gas & Electric) is the country's leading energy efficient utility, and they have created an online clearinghouse for information called the Utility IT EE (energy efficiency) Coalition. One of their prime initiatives is virtualization.  Where a large number of PC's would normally be required, virtualization essentially replaces the individual PC units with small communications relay boxes that connect to a central remote server and require only about 5 watts each to operate:

In most companies, universities or call centers, every employee has a personal computer under his or her desk connected to a keyboard, monitor and mouse. A personal computer typically draws 120 to 200 watts of power, depending on how it is configured.  By moving to virtualization, employers can replace that computer drive with a small box, about the size of two or three packs of playing cards. 

But one campus, Stanford University, found big savings with a much simpler solution. On every university computer they installed a power management software called the BigFix, which creates energy savings by forcing sleep, hibernation and turn-off modes automatically. Stanford is estimating an average of $17 per computer in energy savings x 42,000 computers = big bucks. Currently Stanford has 28,000 computers with the BigFix, and they are saving an estimated $400,000 per year. In addition, PG & E awards rebates for each computer. This money is being used to build the Stanford Green Fund to invest in sustainability measures on campus.

The Mariott used a combination of the above two strategies to dramatically cut energy costs, helping to make the $13 billion company one of the top 12 greenest in the nation. Marriott replaced 3,000 PC with thin clients and virtualized about 40 percent of its server farms and 75 percent of its storage area networks. That virtualization effort saved 33 percent in future server costs, according to Ed Goldman, Mariott's IT leader. They also adopted much more energy efficient units in their data center and replaced 10,000 laptops with EnergyStar-rated computers that have built-in power management. The result: In the past few years, the Mariott's IT costs have stayed flat, while they have greatly increased IT services.

2 big ways for organizations to save energy
Examples of implementations that are saving millions of watts and millions of dollars.