Savor the fruit of others' green IT success

Organizations are contributing to the greater good by making their datacenter best practices transparent Whether for the sake of helping tackle the datacenter power crisis, chipping in to fight global warming, winning over new customers, or racking up bragging rights, recently companies have been readily opening their datacenters in recent months (at least figuratively) and giving the world -- including would-be

Organizations are contributing to the greater good by making their datacenter best practices transparent

Whether for the sake of helping tackle the datacenter power crisis, chipping in to fight global warming, winning over new customers, or racking up bragging rights, recently companies have been readily opening their datacenters in recent months (at least figuratively) and giving the world -- including would-be competitors -- a peek at their special techniques for reaping greater energy efficiency.

Whatever the motivation, the practice is bound to be of use to organizations confounded by high energy bills, limited power for their datacenters, and perhaps directives from above to cut carbon emissions by a hefty chunk (without sacrificing service levels, most likely). The trend will certainly prove invaluable to the Feds as they work to hammer out energy efficiency standards for datacenters.

These collective open-door datacenter policies are already bearing some juicy fruit. Accenture recently compiled results from 17 datacenter case studies supplied by members of the Silicon Valley Leadership Group (SVLG), part of the organization's Data Center Demonstration Project 2008.

In the report, titled "Data Center Energy Forecast Report," Accenture determined that there's hope for the IT industry as it struggles with energy shortages and environmental woes: Based on the successes of the various projects, Accenture supports the EPA's prediction from last year that datacenters can reduce electricity use by as much as 55 percent by 2011, with efficiency gains that could be realized using today’s technologies.

[For a list of the technologies and techniques recommended by the EPA, check out "50 ways to green your datacenter."]

This week, I'd like to share some of the interesting and effective practices as reported by the participating companies. Maybe you'll find inspiration among them to cut energy waste at your own organization -- and perhaps share your success story.

[For other sustainable IT success stories, check out the results from the InfoWorld Green 15.]

Hot air over here, cool air over there

Among the best practices for a datacenter is establishing hot and cold aisles. But some approaches trump others, as demonstrated by the LBNL in a small section of the National Energy Research Scientific Computing Center in Oakland.

infoworld sustainable it lbnl hot aisles cold aisles green datacenter cooling
Typically, cold air blows up through the perforated tiles of a raised floor into the cold aisle and is sucked in to the server intakes to cool the machines. That air is then discharged into the hot aisle and, through return airflow, returns to the cooling unit.

For the test, the LBNL tried a couple of different configurations. The embedded image to the left depicts the two. As described by the report (and pictured here), in Alternate 1 configuration, "the cold aisle was sealed at the top and ends of the racks to prevent hot air re-circulating back into the cold aisle. In the Alternate 2 configuration, plastic partitions sealed the hot aisles off from the cold aisle, and the interstitial ceiling space was used as a return air plenum."

Turns out Alternate 1 was better at separating hot and cold air, resulting in several benefits. Among them, "by minimizing air mixing, and allowing the temperature difference between the supply and return air to increase, LBNL was able to reduce fan power by 75 percent without adversely affecting the server environmental conditions." That translates to a 12 percent reduction in cooling energy on an annual basis.

Additionally, the study suggests that by minimizing the mixing of hot and cold air, "the supply air and chilled water temperatures can be raised to 50 degrees Fahrenheit, which can save 4 percent in chiller energy. Raising that temperature to 50 degrees "and utilizing integrated water-side economizing [aka "free cooling"] can save 21 percent in chiller energy and result in increased chiller capacity," according to the study. Overall, that can mean an overall 18 percent reduction in cooling energy.

[Find out how Microsoft plans to take advantage of "free cooling" to lower its datacenter costs.]

The ideal consolidation destination

Symantec has a rather interesting case study to share: The company consolidated two corporate datacenters, one in California and the other in Arizona, into a purpose-built facility in Arizona. The project entailed reducing server count from 1,635 to 386. Yes, virtualization was involved but only on 81 machines. An astonishing 1,062 servers ended up decommissioned.

The company, of course, has reaped savings by reducing annual datacenter energy consumption from a cumulative 1,965,965 kWh to 1,665,300 kWh -- a savings of 300,665 kWh. That amounts to monthly energy savings of $45,051 -- and part of that is thanks to the fact that Arizona has lower energy rates than does California: 7.87 cents per kWh vs. 11.47 cents.

Let's pause for a moment to examine what a difference those energy rates make: All things otherwise being equal, had Symantec consolidated in California, it would be paying $191,009 per year for energy. In Arizona, it's paying around $131,059 per year. Also, Symantec was able to shed three consultants from its datacenter staff and shave an hour off the time it takes to set up server requirements for new projects.

Symantec says the project took four months to complete and cost $200,350, including freight moves, offsite tape storage, and shipping. If those numbers are accurate, that means a pretty quick ROI.

Seek energy-efficient PDUs

Depending on whom you ask, power conversion and distribution accounts for 20 percent of the wasted power in datacenters - similar to the way energy gets wasted when the PSU (power supply unit) in a PC transforms incoming AC electricity into usable DC electricity. That level of waste generated by inefficient PDUs (power distribution units) can be significant, a lesson learned by the United States Postal Service.

The USPS found that the three PDUs at its San Mateo, Calif. datacenter -- two purchased in the past two years and one from the mid-1980s -- had an average operating efficiency of 94.6 percent. The organization determined that moving to more energy-efficient CSL (Candidate Standard Level)-3 PDUs -- specifically Powersmiths Energy Stations and E-Saver-C3 transformers -- would result in operating efficiency of 98.4 percent.

Four percent may not seem like a huge difference, but USPS projects it will reduce peak demand by 45.6 kW and cooling demand by 13.2 tons per year at its 33,000 square foot datacenter in San Mateo. Annual power consumption will drop by 787,400 kWh, resulting in annual operating savings of $107,736 - or nearly $4,000,000 over 20 years (assuming 3 percent annual energy cost increases above inflation).

The transition also will reduce carbon emissions by 480 tons, as well as put a dent in sulphur dioxide and nitrous oxide emissions.

Yahoo reportedly has enjoyed the benefits of moving to more efficient PDUs as well: By replacing 30 PDUs with CSL-3-compliant models, the company expects to save $130,000 per year, lower peak demand by 69 kW, and reduce annual power consumption by more than one million kWh.

There are plenty of other useful nuggets of sustainable IT information to be gleaned from the Accenture report and various case studies. You can read them all on this Accenture microsite. In meantime, here's hoping more companies will step forward with success stories -- or valuable lessons learned from unsuccessful endeavors.

Ted Samson is a senior analyst for the InfoWorld Test Center and author of the InfoWorld Sustainable IT blog. Subscribe to his free weekly Green Tech newsletter here.

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