Are There Ghosts in Your Closet? Saving Wasted Energy in Computer Server Rooms

Although the huge amounts of energy consumed by “cloud” data centers helping to power our digital economy garnered media attention this week, a recent NRDC report estimates that the computer server rooms and closets in millions of America’s small and medium-sized businesses waste the equivalent energy output of seven medium-sized coal-fired power plants and costs American businesses more than $2 billion in unnecessary electricity expenses annually.


This massive amount of energy and money is lost by American private companies, hospitals, government agencies, educational institutions, and other organizations because their computer server rooms are not managed efficiently. This results in unnecessary energy waste that creates more air pollution and higher prices for consumer products and services.

According to a 2007 U.S. Environmental Protection Agency report to Congress, typical servers in the U.S. only use 5 to 15 percent of their maximum capability on average, while consuming 60 to 90 percent of their peak power, and in many small office-based organizations with on-premise server rooms, as much as 30 percent of their total electricity use may be directed toward powering and cooling servers running 24 hours a day even when performing little or no work.

Fortunately, our analysis also found there are many proven, cost-effective solutions that companies and their IT and Facilities managers can employ in their server rooms to reduce energy use and save money.

The single most important one is to consolidate multiple computing applications from several underutilized servers onto a single, right-sized server. The same amount of work can be done, but substantial amounts of energy and money can be saved through this process known as virtualization. A single virtualized server, even heavily loaded, uses far less energy than multiple, lightly loaded servers. In fact, the savings can be a whopping 50 percent or more. In addition, consolidating servers also reduces server room cooling needs, which for every dollar saved in server electricity costs, saves another dollar in cooling and other overhead costs. And savings don’t end there: virtualized server rooms also save big in hardware, software and maintenance costs, and improve availability and performance!

However, few small and medium organizations have taken advantage of this opportunity. An NRDC 2011 survey found that only 37 percent of small and medium sized organizations had virtualized at least one server, compared to 90 percent of large organizations. Moreover only 23 percent of small organizations planned to increase virtualization in the next 12 months compared to 82 percent in large organizations. The virtualization gap, and consequently the efficiency gap, between small and large organization is large and growing.

Virtualization is not the only savings opportunity in small server rooms. Other opportunities can be found by switching off unused servers, setting servers to go into low-power mode when inactive, tracking energy use, upgrading to more efficient servers, and adjusting server room cooling temperatures  -- all presented in NRDC’s fact sheet entitled “Are There Ghosts in Your Closet? Saving Wasted Energy in Computer Server Rooms.”

The fact sheet also includes a recommendation to consider moving some applications, such as email, data backup, office applications and customer relationship management programs to “cloud” date centers where shared servers provide computing resources to multiple customers.

An upcoming NRDC report will examine “green” vs. “brown” clouds, and how those implementing energy efficiency best-practices and using low-carbon energy sources are far more sustainable than typical server rooms. However, as I wrote in a letter to the editor of the New York Times this week, there also can be “brown” clouds with a larger energy and carbon footprint than on-premise server rooms implementing best-practices.

There’s no doubt that America needs both “green” clouds and “green” on-premise server rooms to speed the transition to a cleaner energy future. Implementing best-practices to ensure the most sustainable computing options also makes the best business sense because it guarantees another type of “green” to companies and their customers in the form of billions of dollars in annual savings.

Stay tuned for our coming "cloud" computing report that will delve more into the topic of cloud data centers and recommendations for making them more sustainable.  

About the Authors

Pierre Delforge

Director of High Tech Sector Energy Efficiency, Energy & Transportation program

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