With data centers and servers acting as the engines that propel much of the global economy, there is an increasing need for an industry-wide approach to work on energy consumption challenges in data centers.

In 2007 a group of influential companies that include Microsoft came together in search of ways to minimize the environmental impact of business enterprise information technology (IT). The result was The Green Grid, a consortium of information technology companies that seek to reduce power consumption and improve efficiency in data centers worldwide.

As Energy Use Rises, IT Costs Rise

Data center power consumption and cooling are two of the biggest energy issues that confront IT organizations today. In many cases, over 50 percent of the power in data centers is used for temperature reduction. By 2015, it's expected that the costs to operate servers will exceed the costs to purchase server hardware.¹

And as energy use grows, IT bills that once accounted for 10 percent of overall enterprise budgets may soon account for more than half. As a result, organizations need more efficient technology to better manage increased computing, network, and storage demands.²

To curb energy use, companies must learn about and adopt practices that offer greater efficiency in line with business productivity. The Green Grid aims to develop and publish best practices for energy management and give companies reliable guidance on how they can reduce energy consumption.

The Green Grid

The Green Grid is dedicated to the advancement of energy efficiency in data centers and business computing ecosystems through:

• The definition of effective, user-focused models and criteria.
• The development of standards, measurement methods, processes and new technologies to improve data center performance against the newly defined criteria.
• The promotion of energy efficient standards, processes, measurements and technology.

Today, more than 100 member companies are charting The Green Grid's course. The Green Grid Board of Directors includes these member companies: AMD, APC, Dell, HP, IBM, Intel, Microsoft, Rackable Systems, SprayCool, Sun Microsystems, and VMware.

Today's Answers, Tomorrow's Standards

The challenge to advance energy efficiency is large. Last year, according to the U.S. Environmental Protection Agency (EPA), data centers in the United States used an estimated 61 billion kilowatt-hours, or 1.5 percent of the electricity in the United States. This number is projected to grow to about 120 billion kilowatt hours in 2011, unless energy conservation steps are enacted. For more details on the EPA's work in this area, see Enterprise Server and Data Center Energy Efficiency Initiatives.

In response, the U.S. Department of Energy (DOE) and The Green Grid have set a common goal of improving overall energy efficiency in data centers by 10 percent by 2011, factoring in current projected data center use.

With a 10 percent improvement by 2011, approximately 10 billion kilowatt-hours would be saved, equivalent to electricity consumed by 1 million U.S. households annually. This energy cutback would reduce carbon dioxide emissions by 6.5 million tons per year—equal to the removal of nearly 1.3 million cars from the road annually.³

To read more about how the U.S. Department of Energy works with business and organizations to reduce energy consumption, see Partnering with Computer Data Centers.

Helping Businesses Have an Impact

To achieve the goal of the advancement of energy efficiency, The Green Grid's members are developing metrics that they and other businesses can use to become more efficient.

The first paper The Green Grid published focused on means to develop metrics for the measurement of energy consumption in data centers and the discovery of ways to improve it. The paper Green Grid Metrics: Describing Data Center Power Efficiency, proposes the use of metrics called Power Usage Effectiveness (PUE) and Data Center Infrastructure Efficiency (DCiE) to help data center operators achieve better efficiencies and improved total cost of operations.

The Green Grid's PUE (DCiE ) metrics can be used by datacenter operators to:

• Quickly estimate the energy efficiency of their data centers.
• Compare the results against other data centers.
• Determine if any energy efficiency improvements need to be made.

PUE uses a simple formula to illustrate how much data center power consumption actually goes to its IT infrastructure, and how much goes toward powering the data center's supporting technology such as power distribution and cooling.

A data center with a PUE of 3.0 uses about three times the energy to run the IT infrastructure than the IT infrastructure consumes. In other words, a server that consumes 500W actually uses 1500W (500W x 3.0) of facility power.

The DCiE value uses a similar formula but with a goal of reflecting the percentage of a data center's power consumption used for its IT infrastructure (a PUE of 3.0 is equivalent to a DCiE of 33 percent). Through the use of these metrics, managers of a data center can begin to understand where significant reductions in power consumption might be obtained and take quick steps to find energy drains and improve efficiency.

Tracking Power Usage Effectiveness (PUE)

Many companies already use the PUE metric to monitor current design for new facilities. For example, Microsoft has been tracking the PUE ratio in many of its data centers for more than three years. Most recently, Microsoft has developed tools for the daily measurement of PUE and other criteria in all of its data centers worldwide. Microsoft requires yearly improvement, and has set specific PUE targets for the year 2012.

Green Grid researchers are also working on methods for an improved definition of productivity in data centers—how much energy is necessary for core task performance. The goal is a more detailed understanding of how much electricity is consumed by temperature reduction and other specific functions within a data center.

White papers on PUE and DCiE are available at The Green Grid Web site.

Guidelines for More Efficient Data Centers

Another paper prepared by The Green Grid offers guidelines for the creation of more efficient data centers. It notes that a growing number of data centers run out of power availability before they run out of floor space—an indicator that inadequate attention was given to the energy needs of centers when they were first planned.

The Green Grid paper also points out that few tools exist for accurately modeling the energy costs of data centers, and that electricity costs are not taken into account, sometimes because payment comes from a budget that is separate from the data center's budget.

A properly designed data center, according to Green Grid researchers, should include:

• A system design that takes power consumption into account.
• A floor design that takes into account the flow of warm or cool air.
• "Tuned" vented floor tiles that optimize air flow.
• Correctly sized physical components that take into account a data center's present and future needs.
• Installation of more efficient power equipment.

Additional details about the creation of more efficient data centers can be found at The Green Grid Web site.

Change the Type of Power Used

The Green Grid also is examining the feasibility of the conversion of data centers from AC (alternating current) to DC (direct current) power.

For instance, its researchers recently peer reviewed a paper published by the Lawrence Berkeley National Laboratory in which researchers studied the impact of the conversion of a data center to a 380 volt DC system from a typical 208 volt AC system.

The reviewers concluded that converting a data center to DC power can result in energy savings of 5–7 percent. But they noted that the study made comparisons to AC-based data centers that did not have optimized systems. Considerable gains can still be made by applying better practices to data centers with today's typical power systems.

Still, the Lawrence Berkeley paper and its review show that innovative ideas can result in significant energy savings.

What Can Data Center Managers Do?

The Green Grid offers IT managers the tools for the evaluation of energy demands and potential energy inefficiency. Through the use of Green Grid information, a data center might realistically begin to reduce its energy usage.

Business decision makers are encouraged to consider Green Grid membership. Membership in The Green Grid is a pathway to interaction with fellow industry stakeholders, and data center efficiency improvements. Also, Green Grid members can influence developers and users of data center technology.

Other benefits of The Green Grid include:

• Attendance and participation in all general meetings of The Green Grid.
• The ability to review and comment on specifications and guidelines prior to adoption by The Green Grid.
• Access to a members-only Web site with exclusive, early access to documents before they are published.

For more information, visit The Green Grid Web site.

Toward an Energy Efficient Future

Microsoft is playing an active role in helping The Green Grid develop into an organization that leads and drives the industry into the next generation of sustainable computing data centers. Due to the work of The Green Grid, the software industry can take advantage of standard interfaces to be developed for data centers and servers. The data center industry will benefit as a result. Currently, The Green Grid is focused on data centers, just one part of the organization's holistic approach to addressing the entire business-computing ecosystem. Standards and criteria will eventually be determined for all relevant IT equipment (computer, network and storage nodes) and non-IT equipment (air conditioning, facility design) that affect energy efficiency.