Institute an ENERGY STAR Purchasing Policy

Look for EPA ENERGY STAR Certified Data Center Equipment

When it comes to energy consumption, not all data center equipment is created equally.  Some products are more energy efficient by design. ENERGY STAR makes the task of finding energy-efficient equipment for your data center easy.  ENERGY STAR certified data center equipment typically costs and performs the same as standard products, but must meet specific energy-efficiency criteria established by US EPA.  A third party testing and certification process makes sure anything that earns the ENERGY STAR label meets the highest standards.  Most major hardware brands offer ENERGY STAR certified models.

Collage of Servers

Whether  your equipment upgrade is for 50,000 or 50 square feet of data center space, simply ask your vendors to provide ENERGY STAR certified:

  • Servers (computers that service and manage networked resources for other computers, wireless devices, telephones, or networked devices)
  • Data storage equipment (disk drives, solid state drives, and other data storage systems)
  • Large networking gear  (routers and switches that pass information among various network interfaces and ports)
  • Uninterruptible power supplies (UPS) (systems that provide electricity to computing equipment in the event that utility power service is disrupted).

You should also look for ENERGY STAR models when you shop for computers, displays, printers, all-in-one devices, scanners, TVs, VoIP phones, small networking equipment, or audio/video equipment.

Work with your Purchasing Department

Purchasing Button

If you have a purchasing department, or someone who signs off on data center purchases, make sure they know to request ENERGY STAR certified data center equipment whenever possible.  The most effective way to ensure your organization purchases ENERGY STAR certified products whenever possible is by instituting a blanket ENERGY STAR purchasing policy. An ENERGY STAR purchasing policy makes buying ENERGY STAR the “default” scenario in your organization: it states that buyers in your organization will show preference for ENERGY STAR certified products whenever they are a viable option.  Use this product purchasing and procurement template to explain your energy-efficient purchasing program to employees and vendors. The template includes sample language that you can include in RFPs and contracts, and you can modify it as needed.

Savings and Costs


Replacing an older server with a newer ENERGY STAR-certified model delivered more processing power for the same energy.

  • At the average US commercial rate for electricity of 10 cents per kilowatt hour (kWh), the energy savings from a single ENERGY STAR-certified server could range from $60 (at 50% utilization) to $120 (at idle) annually, or $240–$480 over the useful life of a server (4 years).
  • In addition to using less energy themselves, ENERGY STAR-certified servers substantially reduce cooling loads in data centers. A general rule of thumb suggests that one watt saved by a server has the added benefit of saving one to two watts of avoided cooling. This yields a total savings of between $480 and $1,440 over the useful lifetime of a server. It's important to note that these power savings come with a substantial increase in performance—at 50% utilization, for example, the newer, more energy-efficient server handles over three times the workload, thereby reducing the number of systems needed to support the same load.

Uninterruptible Power Supplies (UPSs)

ENERGY STAR certified UPSs can cut energy losses by 40-60%.   Depending on the size of your data center, this can lead to considerable lifetime savings:

Savings Associated with ENERGY STAR Certified UPSs Based on IT Load
Data Center IT Load (kW) Annual Savings (kWh) Lifetime Savings ($)










In fact, if all UPS sold in the United States were ENERGY STAR certified, the energy cost savings would grow to approximately $1 billion each year and 15 billion pounds of annual greenhouse gas emissions would be prevented, equivalent to the emissions from more than 1.4 million vehicles.

Tips and Considerations

Note that servers are not always configured by default for optimal energy efficiency.  Check with your hardware manufacturer and your server operating system provider to see if you are taking full advantage of hardware and software features that will reduce power consumption and save energy.  To learn more about these features, see Utilize built-in server power management features.

If you’re planning to purchase new equipment for your data center, be sure to look at expected operating costs, including the cost of electricity, when weighing your options.  Total cost of ownership (TCO) is a financial estimate intended to help buyers determine the direct and indirect costs of a product or system, and can be very helpful when comparing data center equipment.  As its name implies, TCO takes into consideration more than just up-front capital costs.  A thorough TCO analysis includes the total cost of acquisition, operating costs, and costs related to replacement or upgrades at the end of the product life cycle. 

How do ENERGY STAR-qualified servers save energy?

With the following energy-saving features:

  • More efficient power supplies that limit power conversion losses and generate less waste heat, which reduces the need for air conditioning in the datacenter;
  • Improved power quality, which provides building-wide energy efficiency benefits;
  • Real-time measurement of power use, processor utilization, and air temperature, which improves manageability
  • Advanced power management features;
  • Lower power draws when the server is idle.

In addition, server makers must disclosure results from running the Server Efficiency Rating Tool (SERT) on every ENERGY STAR qualified system.  These results facilitate the comparison of energy performance among servers under different types of usage scenarios.