Eco-friendly Web developers are designing in dark colors to save energy. But going black only saves watts on old-style CRT monitors, not LCDs
For most Web site publishers, the phrase "gone dark" has the worst of all connotations. It means a site is no longer running. There's been a system malfunction, a power failure, a protest, or—worst of all—a permanent company shutdown. But for a new crop of eco-friendly Web site designers, "going dark" is taking on a new meaning. It's the new way to go green.
The online buzz over "going dark" began in earnest last January after Mark Ontkush, a self-described "green computing evangelist," wrote a blog post concerning environmentally friendly Web design. Ontkush claimed that if a popular site such as Google (GOOG) switched its home page background color from white to black, it could save hundreds of megawatt hours a year. He based his claim on the fact that certain types of monitors use less energy to display black than white screens. And according to the Environmental Protection Agency, cathode-ray-tube (CRT) monitors and even some flat-panel screens use less energy to display black or dark backgrounds.
Web site designers quickly created a host of black-background Google home pages in response. With names such as Blackle, Darkoogle, and BlackWebSearch.com, the sites initially appear to be Halloween-themed versions of Google's annual April fools' joke. Each, however, does return real Google search results.
Google Defends Itself
Google got wind of its dark alter-egos and came to the defense of its choice of a white background. In an Aug. 9 blog post, Google's green energy czar Bill Weihl wrote that the flat-panel computer screens most common in the U.S. don't save energy displaying black backgrounds. Weihl referred to a test run by an Australian electronics graduate student comparing the power consumption of Blackle and Google on 27 different monitors. On average, CRT monitors saved 10.8 watts per hour using Blackle.
However, liquid-crystal display (LCD) monitors largely used the same or, in several cases, several watts more energy to display the black background. The results were published Aug. 8 on Australian tech news site Techlogg. "We applaud the spirit of the idea, but our own analysis as well as that of others shows that making the Google home page black will not reduce energy consumption," wrote Weihl.
CRT and LCD monitors use different amounts of energy to produce a black screen due to their design, says Scott Gray, a product manager at Hewlett-Packard's (HPQ) commercial display business unit. CRT monitors produce an image by firing a stream of electrons at phosphorescent material within the screen. The various frequencies with which the electrons hit the phosphorescent material produce the unique colors. Black is the default color of the phosphorescent material when no electrons are hitting it and the electron gun is essentially off. "The CRT is using less current with a black screen so there is less electricity used," says Gray. "The peak current is with a bright, well-lit image."
Less Saved With LCDs
LCD screens, on the other hand, are lit via fluorescent tube lights located above or behind the LCD screen. The screen scatters the light, creating the picture. When an LCD screen is on, the lights are also on. "Black is not created by the absence of electricity or by turning off the light," explains Gray. "In a lot of cases, a black screen looks purple because the colors are created by mixing the right pixel elements in the LCD together at the same time (see BusinessWeek.com, 11/22/06, "Bigger TV Screens, Lower Prices").
Google doesn't see much advantage to the black screen, given the dominance of LCD monitors in high tech countries such as the U.S., Japan, and Korea. Ontkush and other eco-computing enthusiasts, however, still see "going dark" as having planet-saving power for the 25% of the world where older CRT monitors are the norm.
Ontkush has revamped his own blog, ecoIron, using a dark green, rust red, and black color palette created by Jonathan Doucette, a graphic designer at Woodard & Curran, an environmental engineering company in Portland, Me. Doucette chose the shades because they took less energy to display than the white and bright hues common on so many Web sites, but were not as boring as some of the dark grayish shades that consumed the least amount of energy. He named the color group "emergy-c" for embodied energy color. "We just wanted to make people aware that there were little things you could do to save energy, especially if you spend a lot of time online on your Web site," says Doucette.
Energy Star Color Ratings
Doucette tested various color palettes with a wattage meter. He found a white screen with black text uses about 74 watts per hour on a CRT monitor. A black screen on a CRT monitor only uses 59 watts. His color palette uses about 60 watts.
Doucette's energy readings were identical to those from the federal Energy Dept. According to the DOE's Energy Star Web site, white and bright background colors use up to 20% more power than black or dark colors. Silver, for example, uses 67 watts compared to gray which only uses 62 watts. Colors that use less than 65 watts include lime green, gray, olive, purple, teal, green, maroon, navy and, of course, black.
The idea of emergy-c appears to have taken off with many Web site designers despite the fact that it only saves power with CRT monitors. A search for emergy-c reveals more than 16,400 links. Many of the sites are in Spanish and Portuguese. Doucette says that he has spoken with press in Brazil, where CRT monitors are still common.
For Best Results, Unplug Your Computer
For computer users with an LCD screen, the Environmental Protection Agency has some advice to reduce energy consumption, besides simply dimming the monitor's brightness. They recommend shutting off the power to computers not in use instead of simply turning devices off or letting them hibernate—both states in which devices draw small amounts of power (see BusinessWeek.com, 5/14/07, "It's Not Easy Buying Green").
The EPA also recommends using Energy Star-rated computer monitors. HP's Gray says that reducing the brightness on monitors can also save a considerable amount of energy, as well as avoid eye problems. Often monitors are set to very bright settings in the stores to stand out, and are shipped at near-maximum brightness, he explained (see BusinessWeek.com, 5/14/07, Slide Show: "The Greenest PCs").
Even if going dark doesn't save much energy on most computers, Web designers have another reason to go black: It looks cool. "Black gives an elegance," says Canadian Web designer Jonathan Henriksen, whose Web pages seem to be influenced by the emergy-c palette but in fact are built that way simply for style. "Black is classy."