Energy-Savings Claims Don’t Add Up for Microsoft’s Windows 7

Microsoft is touting its energy-saving features with the new Windows 7 operating system, but is not making any specific claims about how much power Windows 7 can save, reports Fred Pearce, author of the Guardian’s Greenwash column.

Pearce believes Microsoft should be pushing users to use their PCs more efficiently and giving them fewer choices. He wonders how many IT departments will take the trouble to explore the energy-saving possibilities of the new Windows when, according to Francois Ajenstat, director for environmental sustainability at Microsoft, “probably 70 percent of business users leave PCs on at night,” says Pearce.

As an example, the screen is the biggest energy user for most PCs and laptops, typically consuming 40-50 percent of the power, says Pearce, and Microsoft’s engineering blog recommends the best way for Microsoft to use its software to improve power efficiency would be to set an “aggressive” timeout as the default setting.

But instead, Pearce says, Microsoft has introduced a new low-light mode as an alternative way to save energy without putting the machine into sleep mode, which “sounds like a retrogressive step” if this results in users not using sleep mode.

But the big issue is hardware, Pearce says. Most commentators say the power savings claimed for Windows 7 won’t amount to much until the new system is run on new hardware configured to take advantage of the savings so the faster customers switch to Windows 7 the less their energy demands and the lower their carbon footprint, he says

But this is not the case, according to Pearce. He cites a study by Eric Williams of the United Nations University, who calculated five years ago that most of the carbon footprint for a typical desktop computer comes from manufacturing, which accounts for 81 percent of the footprint.

Pearce’s take: Almost any likely energy savings from running Windows 7 would be wiped out by buying a new computer. He advocates keeping your old machines, even if it is with the old operating system, to cut carbon emissions from your computing.