Recognizing the significant potential for energy efficiency improvements in data centers, EPA recently announced new Energy Star data center product requirements for uninterruptible power supplies (UPS) and new server specifications. Data center storage specifications and large network equipment will be added this year, according to EPA. Data center cooling will join them sometime next year.
According to the EPA's "Report to Congress on Server and Data Center Energy Efficiency Measures," these five areas combined account for nearly all of a typical data center's energy consumption.
To qualify for Energy Star certification, UPS systems are tested by a UPS certification body recognized by EPA. The process examines products based on average power, efficiency and efficiency variation to determine steady-state operation. UPS products meeting EPA's requirements use an average of 35 percent less energy than their standard counterparts.
EPA estimates projected savings from Energy Star UPS are substantial. "If all UPS sold in the U.S. met the Energy Star requirements, energy cost savings would grow to almost $1 billion per year and prevent GHG (greenhouse gas) emissions equivalent to those of more than 1.4 million vehicles," the agency says.
The agency conceded that savings from individual models varies, ". . . but on the data center scale, an Energy Star certified 1 MW (megawatt) UPS could save more than 280,000 kWh (kilowatt hours) over its 15-year lifetime."
EPA says an Energy Star certified server can save an average of 600 to 1,200 kWh annually. "Efficient servers also reduce the data center's cooling load, which means additional savings," says EPA. "These savings may double the overall product savings."
Energy Star 2.0 specification for servers covers servers and processors not addressed in the first specification, which went into effect in 2009 and addressed rack and tower server configurations. Energy Star 1.0 also presents guidelines for future specifications. The 2.0 version also covers blade servers and graphics processing units (GPUs). GPUs are being used in data centers to speed up scientific and mathematical tasks.
A major goal of the Energy Star program for data center products is providing standardized, reliable information on product energy performance. So, Energy Star labeled products for data centers come with a power and performance datasheet listing product information and detailed test results.
For example, an Energy Star qualified UPS will have its efficiency reported at 25 percent, 50 percent, 75 percent and 100 percent loads, enabling data center operators to construct a load curve and determine how efficient it will be when installed on site.
"A server qualified for Energy Star will provide both its idle power consumption as well as results for a variety of active performance energy efficiency metrics," says EPA. These metrics allow data center operators to see how efficient the server is for the workloads it will encounter at their individual sites.
The Energy Star for UPS program covers products rated higher than or equal to 1,500 watts. The initiative is part of EPA's electrical equipment efficiency improvement program.