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Is Your Data Center a Gas Guzzler?

You may be surprised to learn that most CIOs are unable to answer this question: "How energy efficient is your data center?" Steve Sams, vice president of Site and Facilities Services in IBM Global Technology Services, offers advice on how to cut down energy use in your data center.

You may be surprised to learn that most Chief Information Officers (CIOs) are unable to answer this question: "How energy efficient is your data center?" According to recent studies, 80% of CIOs have never conducted an energy audit and 77% don't see the energy bill, which is usually handled by the Chief Financial Officer.  

IBM has met with tens of thousands of clients in the past year to help them better understand that data centers are consuming 10 to 30 times the energy per square foot as their office space.

IBM has developed some very simple steps for CIOs to take that can help save 15% to 40% of their annual data center energy consumption with less than a two-year payback. For a typical 25,000-square-foot data center paying $0.12 per kilowatt hour for electricity, this can translate into as much as $1 million in annual energy savings.

Tree Hugger or  Gas Guzzler?

To help CIOs determine if their data centers are energy-efficient tree huggers or gas-guzzling big rigs, we can use a simple industry metric which measures energy use and is a "miles per gallon" equivalent for data center energy efficiency. The Green Grid (an industry consortium) created the Data Center Infrastructure Efficiency (DCiE) metric that identifies how much energy is spent on the productive use of IT. The ideal would be to have 100% spent on IT, but energy must still be provided to the physical infrastructure for cooling and conditioned power.

A 2006 industry report indicated that 20 data centers in California rated as very energy efficient, with an average DCiE of 54%. In the past year, IBM conducted more than 30 energy assessments around the world and found the average DCiE was 43% --- much less energy efficient than the prior study. This means that 43 cents of every energy dollar are spent to power IT, while 57 cents are spent on the physical infrastructure for conditioned power and cooling.  

The fact is, the majority of today's data centers are not energy efficient, since most were built before 2001. We know older infrastructure and IT equipment are not as energy efficient as some of the newer technology. We also know these data centers need to have a useful life of 20 to 30 years, so helping to improve their energy efficiency to 60% to70% (a reasonable target for a DCiE) is both desirable and possible.

Where Does the  Energy Go?

CIOs need to understand where the energy is used in the data center before they can deter mine how to lower its use.  Energy  is used by the IT equipment (servers, storage and network equipment), as well as the physical infrastructure equipment, like the computer room air conditioners, uninterruptible power supplies and chillers. Most CIOs are surprised to learn that 60% to 70% of the energy in a data center is used on the physical infrastructure equipment, while only 30% to 40% is used on the IT equipment.

How Can Enterprises Save?
Server and storage consolidation and virtualization are good first steps to address the IT energy portion of the equation, but CIOs also need to address the physical infrastructure energy inefficiencies. Here are three things CIOs can do to improve their data center energy efficiency.

1. Apply some quick hitters
There are a number of "quick hitters" which can provide the foundation for additional energy savings. Returning to basic air-flow management best practices in data centers can yield up to six percent annual savings. Focusing on closing holes in the raised floor, strategically locating perforated tiles and baffles, and implementing hot and cold aisle configurations are easy to implement at low cost. Clients with a typical 25,000-square-foot data center could save as much as $79,000 annually (six percent) on the energy costs for their facilities, reaching payback in approximately seven months.

2. Get rid of the meat locker The mechanical systems --- chillers, humidifiers and computer room air conditioners --- are the biggest users of energy. Removing inefficiencies in these systems is the best short-term payback area for energy efficiency. Many data centers are like meat lockers, with room temperatures set to be very cold to address a particular hot spot. By increasing the temperature or set points on cooling equipment by a few degrees and taking advantage of free cooling (using the air temperature outside to cool the data center inside), it is possible to save up to another 10% of the infrastructure energy consumption annually.

3. Right-size the physical infrastructure
We've heard a lot about right-sizing and optimizing IT resources, and the same principle applies to the physical infrastructure.  By right-sizing the cooling and power systems, clients could achieve 20%  or more in annual energy savings. These solutions include the use of supplemental cooling techniques such as adding IBM's rear-door heat exchanger, implementing variable-speed drives, and improving the UPS efficiency by better matching the physical infrastructure capacity to the IT load. Clients need to evaluate these options against the expected life of their existing data centers, since these alternatives require more investment to implement and time to pay back (six years or longer).

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