|
 Blackle is a search engine, powered by Google, which seeks to save energy by rendering everything black. Have a look at it; the entire page, apart from a dark grey title and a few pieces here and there, is black.
Why? Apparently it saves energy to have black, or dark colored, backgrounds (good news for this site…although, to be honest, I can’t claim to have been aware of this issue when designing the site). So, is this true? Can we really save energy by only visiting darkly colored sites? Turns out we can…sometimes.
At the moment the world is fairly evenly split between CRT and LCD monitors, with roughly 405 million and 401 million respectively of each. CRT technology works by moving an electron beam back and forth across the back of the screen. The front of the screen is covered with red, blue and green phosphors. To produce white, the electron beam is directed at the phosphors; however a black screen doesn’t require the beam to be fired.
This is not the case, however, with LCD monitors, which have no phosphors. Instead, LCD displays rely on an array of thin-tube fluorescent bulbs that provide a constant source of light to create a white screen. To make it black, LCDs rely on a diffuser to block this light.
It’s clear that when we’re talking about CRT monitors, black screens save power – anywhere up to about 25 watts depending on the size of the screen. With LCD screens there is more of a debate. Google green energy boss Bill Weihl disputes the idea that black saves more power when talking about LCDs. "We applaud the spirit of the idea, but our own analysis as well as that of others shows that making the Google homepage black will not reduce energy consumption," he writes. In fact, he goes so far as to suggest that on flat-panel monitors, displaying black may actually increase energy usage due to the use of a diffuser to block the light.
On the flip side of the coin, a 2002 research study produced by Lawrence Berkeley National Laboratory entitled "Energy Use and Power Levels in New Monitors and Personal Computers reports that black screens consistently require less energy than white screens, regardless of whether the monitor is a CRT or LCD.
What to believe? I’m not sure, but certainly with regard to LCDs, the savings we’re looking at are far less than the CRT numbers; perhaps a matter of a couple of watts, tops. For more information on this topic, check out this article.
Either way, I’ll be contacting the All Blacks management to suggest they start promoting them as the world’s most energy efficient sporting team.
|
