Data Center Management: Top 6 Strategies for Saving Energy and Money

Monday February 6, 2012
Posted at 11:00


If you’re an IT professional, facility manager, or energy manager and operate a data center, then you know how much energy it takes to keep all your servers running smoothly. You may also be aware of how much money that energy costs your company every month. Fortunately, there are several changes you can make to reduce energy costs while maintaining — and even increasing — your data center’s performance. According to ENERGY STAR, here’s a list of the top five strategies you can implement in your data center to start saving energy and money right away.

1. Server Virtualization

As you may know, a virtual server is a software implementation of a server. It executes programs like a real server does but allows you to run multiple independent “servers” on a single physical server. The idea is that the virtual servers use more of a physical server’s processing power, which means you can run fewer physical servers and cut energy costs.

Estimated Savings: Consolidation ratios between 10:1 and 15:1 can be achieved with today’s servers, resulting in reductions in data center energy expenses from between 10 percent and 40 percent.

2. Decommissioning of Servers

Aged servers with no use that are still running and eating up energy costs, so-called “comatose” servers, are a problem in data centers. Unless you have a rigorous program of decommissioning comatose servers, it’s likely that between 15 percent and 30 percent of the equipment in your data center is comatose, according to Kenneth Brill, executive director of the Uptime Institute. Removing just one comatose server produces a “cascade effect” of energy savings from the server, power distribution unit, UPS, cooling system and building transformers.

Estimated Savings: When Sun Microsystems decommissioned unused servers, for example, the company reported an 8 percent to 10 percent cut in equipment load and an 11 percent to 14 percent decrease in total load.

3. Consolidation of Lightly Utilized Servers

The traditional “one workload, one box” approach to server provisioning in data centers results in an abundance of underutilized servers. Since typical server utilization is about 5 percent to 15 percent, most servers run at or below 20 percent utilization most of the time, but still require full power to operate. To solve this problem, combine multiple applications onto a single server and a singe OS instance, cluster servers to reduce the number of backup or standby servers, downsize the application portfolio to eliminate redundant applications and virtualize servers whenever you can.

Estimated Savings: Given that the average U.S. server’s energy cost is about $820 per year, according to Stanford University, the potential for savings is significant.

4. Better Management of Data Storage

Hard disk drives and media that retain digital computer data can use a lot of energy. According to some experts, however, “white space,” or the amount of storage that goes unused, averages about 70 percent per device. And, of the 30 percent that is utilized, some of that can be attributed to duplicate data. You can better utilize your data storage by deploying storage resource management (SRM) tools, automating storage provisioning and deploying thin provisioning, organizing storage by tiers, installing a massive array of idle disks (MAID) for tier 3 storage and considering the advantages of solid state storage, which has no spinning disk to power.

Estimated Savings: Better data storage management can lead to significant energy savings; MAID solutions alone can reduce energy costs associated with data storage by 60 percent or more.

5. Purchasing More Energy-Efficient Servers, UPSs and PDUs

One of the most direct ways to increase the energy-efficiency of your data center going forward is to simply start purchasing more energy-efficient technology, including servers, UPSs and PDUs. The latest OSs can also play a role. Windows Server 2008 R2, for example, includes a number of efficacy improvements. It continually alters the power states of server processors in response to utilization workloads and includes features such as Core Parking, Time Coalescing and Intelligent Timer Tick Distribution, or Tick Skipping, which helps keep processor cores in deep sleep when they’re not needed.

Estimated Savings: New servers are typically about 30 percent more efficient than older servers (while being able to perform three times the workload at 50 percent utilization). New, energy efficient UPSs typically hit efficiency rates from 92 percent to 95 percent. New PDUs are about 2 percent to 3 percent more efficient.

6. Hot Aisle/Cold Aisle Layout

Many data centers logically place their server racks in neat rows from front to back, with server cold air intakes at the front and hot air exhausts at the back. While this may seem like a logical way to arrange your racks, it means as the server racks go back, they begin to take in warmer air, which can result in higher fan speeds to keep the servers in the back rows at ideal operating temperatures. A better solution is to implement the hot aisle/cold aisle layout, which mandates that server racks are arranged so that cool air intakes face each other and warm air exhausts face each other. That way, you ensure that your cool air intakes are constantly receiving cool air.

Estimated Savings: According to the U.S. Department of Energy, when used in combination with appropriate containment, a hot aisle/cold aisle layout scheme can reduce fan energy use from 20 percent to 25 percent.

Do you agree or disagree with ENERGY STAR’s recommendations? Have you implemented these or other energy-saving strategies in your data center? Leave us a comment below and let us know how they’re working.


ENERGY STAR, “Data Center Energy Efficiency Strategies.”

How to Save Money with an IT Power Management Policy

IT needs consume a lot of energy

Power management for IT departments is becoming increasingly important for large and small companies alike. In the commercial sector, IT equipment and related communication technologies — computers, monitors, servers, printers, telephones, video conferencing equipment, etc. — now account for about 10 percent of an organization’s energy use.

According to Gartner Group, an information technology research and advisory company, organizational waste from IT equipment is significant:

- PCs and their monitors consume nearly twice the electricity of servers.
- Even when a monitor is turned off or set to standby, a PC consumes almost as much power as a fully-powered, but idle PC.
- Enterprise organizations waste close to $4 billion, or one-third of their annual energy consumption, powering PCs that aren’t being used.
- Even when not in use, the majority of enterprise PCs are kept on 24 hours a day, 7 days a week, all year round.
- Most PC users in organizations incorrectly believe that IT departments need computers to be left on all the time in order to offer access to critical system maintenance or system updates.
- Typical business hours account for less than 30 percent of a PC’s use, which means that PCs are wasting electricity more than 70 percent of the time.

A typical PC consumes between 400 kilowatt-hours and 600 kilowatt-hours of electricity per year, depending on factors such as brand, components and workload. In January 2008, the average price of electricity in the United States was $0.0898 per kilowatt-hour and ranged from $0.0533 in Idaho to $0.2536 in Hawaii. Based on these numbers, if all computers in a 10,000-machine organization were left on all the time, the organization’s annual cost for electricity would be between $1,867,632 and $13,329,216.

A power management policy for PCs alone can save an organization between $20 and $60 per computer per year.

Although Gartner Group estimates that organizations can save up to 50 percent of their energy costs on PCs alone by adopting a power management strategy, most IT departments fail to institute power management programs that result in PC users taking advantage of even the most minimal power saving features available on their machines.

7 Energy-Saving Tactics for Your Organization’s IT Power Management Policy

Although an energy-saving power management policy may seem like an expensive thing to develop and implement, IT departments can often combine a little employee education with existing, free or inexpensive power management tools for an affordable policy that saves far more money than it requires.

1. Turn off IT equipment during non-business hours

Completely shutting down computers, monitors, printers, copiers and other IT-related equipment when the office is closed not only conserves roughly 70 percent of the energy those devices would otherwise consume, it also cuts air conditioning costs by reducing internal heat gain. Don’t leave equipment in Sleep or Standby modes overnight because a small amount of power will continue to be drawn.

2. Be careful when using computer screen savers

While screen savers may help prevent burn-in on some types of monitors, they don’t always do a good job of saving energy during periods of inactivity. For organizations that use screen savers, make sure they’re compatible with computers’ power management features.

3. Activate power-saving features in office equipment

All modern printers, copiers, fax machines and other common office machines have built-in power management features. Make sure that these features are activated and running properly.

4. Opt for laptops and notebooks over desktops

Most laptop and notebook computers are more than powerful enough for typical office use. Although the initial investment might be a bit more expensive, laptops and notebooks use 90 percent less energy than desktops.

5. Install plug load controllers in cubicles

Plug load controllers use a motion sensor incorporated with a plug load surge suppressor and can control multiple loads, such as computers, monitors, task lighting and fans. Inactive equipment is easily shut down when cubicles are unoccupied.

6. Purchase or lease ENERGY STAR–certified office equipment

Office and IT equipment certified by ENERGY STAR is energy-efficient and uses power management features to automatically power down during periods of inactivity, resulting in energy savings of up to 50 percent or more.

7. Purchase or lease ENERGY STAR–certified vending machines

While vending machines may not seem like a big deal at first, this equipment runs all the time to keep drinks and food cold including nights and weekends. Vending machines certified by ENERGY STAR incorporate energy efficient compressors with refrigeration and lighting controls that can save 30 percent to 50 percent when compared to the energy use of older, non-certified equipment.


Triumfant white paper, “Green IT Power Management.”