Lowering the Google Wattage

If there is in fact Google after death, it probably looks something this: an all-black version of the omnipresent search engine, designed to save energy by cutting down on all that white light.

Two new sites, Blackle.com and Darkoogle.com, both use Google's custom search, which can be embedded in other sites, to mimic the real thing while using fewer watts in the process. Unlike paper, where white tends to indicate a blank page, pumping out all that light on a monitor takes energy.

The idea for the sites tracks back to a Jan. 20, 2007, entry on the blog ecoIron,  in which the author, Mark Ontkush, estimated that a "black Google" could save 750 megawatt-hours a year, based on traffic figures for Google.com and data on how many watts a monitor uses for an all-white screen vs. an all-black screen. (For comparative purposes, a 100-watt lightbulb consumes one kilowatt-hour in 10 hours of service; there are 1,000 kilowatt-hours in a megawatt-hour.)

Neither site wins points for readability. Blackle, the more trafficked of the two, uses a light gray font color over the dark backdrop, while Darkoogle uses a bright green typeface that resembles the prehistoric days of the green monochrome displays of the early personal computers.

But even as Blackle makes the rounds of the listserv circuit, winning converts who like the concept and pass the word along, others are questioning how big a difference it's actually making. The website Techlogg.com tested out the energy consumption of Google vs. Blackle on eight different monitors and found a surprising result: While the four cathode-ray-tube models--the older, bulky monitors that work like TVs--did save about 10.8 watts on Blackle, the newer LCD screens actually used more energy on the dark site. Techlogg attributed the difference to the fact that liquid crystal displays, which are backlit at all times, actually require more energy to block the light.

But Edward Kelley of the Flat Panel Display Laboratory at the National Institute of Standards and Technology remains unconvinced. There are so many variables that go into energy consumption in monitors, he says, that overall it won't make much difference.

"The difference it would make is trivial," Kelley says. Instead, he offers a better solution for saving a little energy on the monitor: "Turn the thing off for five minutes."

--Chris Wilson