Many people are familiar with the Energy Star rating system used to indicate the energy efficiency of monitors, PCs and consumer appliances.
But from this year the US rating system will extend to cover datacentre equipment, including servers, and eventually storage and networking products.
However, analysts and IT hardware suppliers are not convinced the rating system will provide an adequate environmental guide for IT directors, because of the complex and varied nature of datacentre operations.
Energy Star is a ratings guide created by the US Environmental Protection Agency (EPA), in conjunction with the US Department of Energy, and has been used as the eco-standard for many products for several years.
In December 2006, the EPA turned its attention to datacentres, after calculating that US businesses could save up to $4bn annually in electricity costs if they used more energy-efficient datacentre equipment.
As a result, the EPA developed a draft Energy Star server qualification - the Energy Star Program Requirements for Computer Servers specification - which is due for release this year.
Meanwhile, hardware suppliers are preparing to release the first servers that carry the new rating.
Among these is Hewlett-Packard. "In 2009, there will be an Energy Star specification for a small number of business server types," says Steven Gonzalez, ISS product marketing manager for HP ProLiant power and power efficiency.
HP intends to offer a number of Energy Star versions of servers rated under the upcoming server specification, says Gonzalez. But he adds that with the specification still under development, it would be "imprudent" to make promises about which specific models and lines will be Energy Star rated.
Gonzalez says that over 1,000 models of HP office products are currently Energy Star qualified. These include many PCs, which comply with the recently released version 5.0 Energy Star Program Requirements for Computers specification.
But he adds that the 5.0 specification does not apply to the types of servers that HP sells in its ProLiant and Integrity business server ranges, and rating servers requires a completely different set of criteria.
Gonzalez candidly notes that Energy Star ratings will have drawbacks in a datacentre context, and he urges IT directors to examine other power-related benchmarks as well.
"With the complexities in the operations of IT servers there is not an easy solution to create specifications, as every component in a server can change the energy efficiency of that server, from the power supply to the processor or the memory," he says.
Sun is another supplier participating in the EPA Energy Star programme. Roy Reed, Sun European standards manager, says it is difficult to predict which Sun servers will carry the Energy Star branding, as the specification for servers is still in draft form and subject to change.
However, Dell argues that its server power supplies are already energy efficient, and that it offers many desktop, workstation, laptop, display, TV and printer models that meet the EPA requirements for Energy Star.
Tom Moriarty, EMEA regulatory and environmental compliance manager, says that in May 2007, Dell became the first in the industry to achieve 80 PLUS Gold certification for a server power supply.
"The 80 PLUS certification enables our customers to compare and contrast power supplies based on criteria from Energy Star and the Climate Savers Computing initiative.
Networking and storage manufacturers are also preparing for Energy Star, though they are wrestling with draft specifications.
"As the Energy Star rating system evolves for storage, we anticipate rating our products in the appropriate categories," says Rona Newmark, senior vice-president for research and corporate strategy at EMC.
But she added, "At this time, it is not possible to predict how the categories will be structured, so it is not possible to identify which specific products we will rate."
Networking suppliers also note that it is still early days for Energy Star in the datacentre.
Matt Walmsley, EMEA solutions marketing manager at 3Com, says, "To date, the Energy Star programme has yet to provide specifications directly applicable to networking equipment, apart from those using external power adapters."
Clive Longbottom, service director, business process analysis at analyst firm Quocirca, says the bottom line is that Energy Star ratings are unlikely to provide a definitive guide to the green impact of datacentre equipment.
"The problem is that what is being mooted is a very simple approach, along the lines of the ratings for consumer white goods such as dishwashers," he says.
Longbottom adds that, once rated, today's state-of-the-art servers will still be marked as energy compliant, despite being superseded in future years by more efficient ones.
Longbottom argues that India has a much better approach and is looking at providing equipment with a "dynamic" star rating system, which allows it to be automatically downgraded by one star within a specified period of time.
"A datacentre will then be given an overall score based on the star rating of all the items within the datacentre, providing the impetus to organisations to upgrade not only single items of kit, but their overall approach in order to get a better rating," he says.