Data Center "X" just announced a 2 MegaWatt expansion to their facility in Northern California. A major increase in data center capacity, and a source of great joy for the company. And the source of potentially 714 additional tons of carbon introduced each month into the environment.

Many groups and organizations are gathering to address the need to bring our data centers under control. Some are focused on providing marketing value for their members, most others appear genuinely concerned with the amount of power being consumed within data centers, the amount of carbon being produced by data centers, and the potential for using alternative or clean energy initiatives within data centers. There are stories around which claim the data center industry is actually using up to 5% of power consumed within the United States, which if true, makes this a really important discussion.

If you do a "Bing" search won the topic of "green data center," you will find around 144 million results. Three times as many as a "paris hilton" search. That makes it a fairly saturated topic, indicating a heck of a lot of interest. The first page of the Bing search gives you a mixture of commercial companies, blogs, and "ezines" covering the topic - as well as an organization or two. Some highlights include:

• 42U (Private Company Pitching Green)
• Green Data Center Blog
• Web Host Industry Review – Green Data Center Info (ezine)
• http://www.greenhousedata.com/ (private advocacy group)
• http://www.thegreengrid.org/ (industry Organization)

With this level of interest you might expect just about everybody in the data center industry to be aggressively implementing "green data center best practices." Well, not really. In the past month the author (me!) toured not less than six commercial data centers. In every data center I saw major best practices violations, including:

• Large spacing within cabinets forcing hot air recirculation (not using blanking panels, as well as loose PCs and tower servers placed adhoc within a cabinet shelf)
• Failure to use Hot/Cold aisle separation
• High density cabinets using open 4 post racks
• Spacing in high density server areas between cabinets
• Failure to use any level of hot or cold air containment in high density data center spaces, including those with raised floors and drop-ceilings which would support hot air plenums

And other more complicated issues such as not integrating the electrical and environmental data into a building management system.

The Result of Poor Data Center Management

The Uptime Institute developed a metric called Power Utilization Efficiency (PUE) to measure the effectiveness of power usage within a data center. The equation is very simple, the PUE is the total facility powe3r consumption divided by the amount of power actually consumed by either internal IT equipment, or in the case of a public data center customer-facing or revenue-producing energy consumed. A factor of 2.0 would indicate for every watt consumed by IT equipment, another watt is required by support equipment (such as air conditioning, lighting, or other).

Most data centers today consider a target value of 1.5 good, with some companies such as Google trying to drive their PUE below 1.2 – an industry benchmark.

Other data centers are not even at the point where they can collect meaningful PUE data. The previous Google link has an extended description of data collection methodology, which is a great introduction to the concept. The Uptime Institute of course has a large amount of support materials. And a handy Bong search reveals another 995,000 results on the topic. No reason why any data center operator should be in the dark or uniformed on the topic.

So let's use a simple PUE example and carbon calculation to determine the effect of a poor PUE:

Let's start with a 4 MW data center. The data center currently has a PUE of 3.0, meaning of the 4 MW of power consumed within the data center 3MW are consumed by support materials, and 1MW by actual IT equipment. In California, using the carbon calculator, this would return 357 tons of carbon produced by the IT equipment and 1071 tons of carbon produced by support equipment such as air conditioning, lights, poorly maintained electrical equipment, etc., etc., etc…

1071 tons of carbon each month, possibly generated by waste which could be controlled through better design, management, and operations in our data centers. Most commercial data centers are in the 4~10MW range. Scary.

The US Department of Energy recently did an audit entitled "Department of Energy Efforts to Manage Information technology in an Energy-Efficient and Environmentally Responsible Manner," which highlights the fact even tightly regulated agencies within the US Government have ample room for improvement.

"We concluded that Headquarters programs offices (which are part of the Department of Energy's Common Operating Environment) as well as field sites had not developed and/or implemented policies and procedures necessary to ensure that information technology equipment and supporting infrastructure was operated in an energy-efficient manner and in a way that minimized impact on the environment." (OAS-RA-09-03)

What Can We Do?

The easiest thing to do is quickly replace all traditional lighting with low power draw LED lamps, and only use the lamps when human beings are actually within the data center space working. Lights generate a tremendous amount of heat, and consume a tremendous amount of electricity. Heat=air-conditioning load if that wasn't already obvious. Completely wasted power, and completely unnecessary production of carbon. If you are in a 10,000sqft data center, you may have 100 lighting fixtures in the room. Turn them off.

If your data center requires security cameras 24x7, consider using dual-mode cameras that have low light vision capability.

Place blanking panels in all cabinets. Considering removing all open racks from your data center unless you are using them for passive cabling, cross-connects, or very low power equipment. Consider using hot or cold aisle containment models for your cabinet lineups. Lots of debate on the merits of hot aisle containment vs. cold aisle containment, but the bottom line is that cool air going into a server makes the server run better, reduces the electrical draw on fans, and increases the value of every watt applied to your data center.

Consider this – if you have 10 servers using a total of 1920 watts (120v with a 20 amp breaker <at 16 amps draw>), that gives you the potential of running those 10 servers at full specification draw. That includes internal fans which start as needed to keep internal components cool enough to operate within equipment thresholds. If the server is running hot, then you are using your full 192 watts per server. If the server is running with cool air on the intake side, no hot air recirculation producing heat on the circuit boards, then you can reasonably expect to reduce the electrical draw on that component.

If you are able to reduce the actual draw each server consumes by 30~40% by removing hot air recirculation and keeping the supply side cool, then you may be able to add additional servers to the cabinet and increase your potential processing capacity for each breaker and cabinet by another 30~40%. This will definitely increase your efficiency, cost you less in electricity and power, give you additional processing potential.

Sources of Information

Quite a few sources of information, beyond the Bing search are available to help IT managers and data center managers. APC probably has the most comprehensive library of white papers supporting the data center discussion (although like all commercial vendors, you will see a few references to their own hardware and solutions). HP also has several great, and easy to understand white papers, including one of the best reviewed entitled "Optimizing facility operation in high density data center environments" – a step-by-step guide in deploying an efficient data center.

The Bing search will give you more data than you will ever be able to absorb, however the good news is that it is a great way to read through individual experiences, including both success stories and horror stories. Learn through other's experiences, and start on the road to both reducing your carbon footprint, as well as getting the most out of your data center or data center installation.

Give us your opinions and experiences designing and implementing the green data center – leave a comment and let others learn from you too!

John Savageau, Long Beach

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