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Covered Product Category: Enterprise Servers

The Federal Energy Management Program (FEMP) provides acquisition guidance and Federal efficiency requirements for enterprise servers, which are covered by the ENERGY STAR program. Federal laws and requirements mandate that agencies meet these efficiency requirements in all procurement and acquisition actions that are not specifically exempted by law.

Meeting Energy Efficiency Requirements for Enterprise Servers

Buy products with the ENERGY STAR label or select products by checking the ENERGY STAR Qualified Products list. Federal buyers can assume that ENERGY STAR-qualified products are life cycle cost effective; if the agency finds this is not the case, or that a qualified product is not reasonably available, the head of the agency must document in writing this justification for an exception.

Reducing Energy Costs: Save an Average of $356 by Purchasing ENERGY STAR-Qualified Enterprise Servers

FEMP calculated1 that the ENERGY STAR-qualified product is cost effective if it is priced no more than $356 above the average model that is not ENERGY STAR-qualified. Note that enterprise servers that exceed the ENERGY STAR specification requirements can save even more energy.

The complete cost effectiveness example and associated assumptions are provided in Table 1.

Table 1. Lifetime Savings for an Efficient Enterprise Server


Best Available2

Efficiency Level

Less Efficient

Annual Energy Use


1,211 kWh/yr

2,308 kWh/yr

Annual Energy Cost




Lifetime Energy Cost (4 years)




Lifetime Energy Cost Savings





ENERGY STAR is cost effective. An efficient product is cost effective when the discounted savings (from avoided energy costs over the life of the product) exceed the additional upfront cost (if any) compared to a less-efficient option. ENERGY STAR and FEMP consider upfront costs and lifetime energy savings when setting required efficiency levels so Federal purchasers can assume that ENERGY STAR-qualified and FEMP-designated products meeting efficiency requirements are life cycle cost effective. However, users wishing to determine cost effectiveness for their application may do so using the cost effectiveness example above.


Products meeting FEMP-designated efficiency requirements or ENERGY STAR performance specifications may not be life cycle cost effective in certain low-use applications, such as when a device is being purchased for backup purposes and will remain unplugged or off for most of its useful life. For average or high-use applications, purchasers will find that energy-efficient products have the lowest life cycle cost.

Complying with Contracting Requirements

These requirements apply to all forms of procurement, including construction guide specifications and project specifications; renovation, repair, maintenance, and energy service contracts; lease agreements; acquisitions made using purchase cards; and solicitations for offers. Energy efficiency requirements should be included in both the evaluation criteria of solicitations and the evaluations of solicitation responses.

Federal Acquisition Regulation (FAR) Part 23.206 requires Federal agencies to insert the clause at FAR section 52.223-15  in solicitations and contracts that deliver, acquire, furnish, or specify energy-consuming products. FEMP recommends that agencies incorporate efficiency requirements into both the technical specification and evaluation sections of solicitations. Agencies may claim an exception to these requirements through a written finding that no ENERGY STAR-qualified or FEMP-designated product is available to meet the functional requirements, or that no such product is life cycle cost effective for the specific application.

Buying Energy-Efficient Enterprise Servers

Server energy efficiency improves significantly from generation to generation. The latest servers deliver much higher “performance per watt” than three- to four-year-old servers. Establish server refresh policies that take into account increases in generation-on-generation energy efficiency and power manageability improvements. The savings in energy and software costs can sometimes justify a faster refresh than expected.

Purchasing high-temperature-tolerant servers can also save energy by reducing cooling needs. Refreshing servers is also a good opportunity to consider consolidation, as new servers usually have much more capacity than the ones they replace.

For ENERGY STAR-qualified servers, manufacturers are encouraged to provide a hyperlink to a detailed power calculator on their websites. Purchasers can use the power calculator to understand power and performance data for a specific server model or model family. Full power load and idle power draw for these server models can also be found on Energy Star’s Qualified Products list.

Using Enterprise Servers Efficiently

Servers that comply with the Energy Star Version 2.0 specification offer processor power management that is enabled by default in the BIOS and/or through a management controller, service processor, and/or the operating system shipped with the Enterprise Server. Whenever possible, the default power management setting should remain in place, which helps reduce power consumption at times of low utilization. The “Available Power Saving Features” vs. “Enabled Power Features” when the products are shipped are listed in Energy Star’s Qualified Products list.

ENERGY STAR-qualified servers collect data on Input Power, Processor Utilization, and Inlet Air Temperature, and users can access these data via one of the following methods: 1) for products with a pre-installed OS, the OS includes all necessary drivers and software for data access; 2) for products without a pre-installed OS, documentation on how to access data is provided on the manufacturer’s website, or via electronic or printed documentation shipped with the Enterprise Server. The collected data can inform users how to optimize operation of servers by observing the correlation between processor utilization and input power. Inlet air temperature data can inform the operation set-point of cooling equipment in order to achieve higher energy efficiency in the server space.

Optimize Server Utilization and Turn off Unused Servers

An Uptime Institute survey suggests that close to 30% of servers are unused in data centers, with each one costing over $4,000 per year in energy, space, and maintenance costs, without adding business value. To save energy and important business resources, create and regularly update a server hardware and application inventory to track the number of applications running on each server, and identify unused servers or servers with low utilization. These servers can then be consolidated, with some servers eventually turned off or reassigned.

Consolidate and Virtualize Applications

Consolidating multiple applications on a smaller number of servers accomplishes the same amount of computational work, but lower energy consumption per application. Virtualization is a proven method for consolidating applications, allowing multiple applications to run in their own environments on shared servers. Increasing server utilization reduces both the number of servers required to run a given number of applications and overall server energy use.

Examine Power Backup Requirements

Redundant equipment in the power delivery chain increases capital cost and consumes additional energy, as power conversions create heat which must then be removed. Not all information technology equipment needs backup power. For example, some applications fail-over to other IT equipment, so dual individual power supplies may not be required. Backup requirements should be determined on a case-by-case basis to avoid costly redundant equipment that consumes additional energy.

Finding More Information

Lawrence Berkeley National Laboratory provided supporting analysis for this acquisition guidance.

Updated January 2014

1 Based on the following assumptions: Assumes both the ENERGY STAR and less efficient servers are in idle mode all 8,760 hours of the year and consume 138 and 264 Watt in idle mode, respectively. Both are managed servers. Assumes product lifetime of four years. The electricity rate is $0.09 per kWh, the average at U.S. Federal facilities. Future electricity price trends and a 3% discount rate are based on Federal guidelines (NISTIR 85-3273-28) and are from the Annual Supplement to NIST Handbook 135 and NBS Special Publication 709, Energy Price Indices and Discount Factors for Life Cycle Cost Analysis, 2013.

2 Data on best available models were not available at the time of publication. Check the ENERGY STAR Qualified Products list for Enterprise Servers for more information about the energy consumption of enterprise servers that exceed the ENERGY STAR performance requirements.