Blackle - Saves energy?

[TransformX]

"…If Google had a black screen, taking in account the huge number of page views, according to calculations, 750 mega watts/hour per year would be saved."

In response Google created a black version of its search engine, called Blackle, with the exact same functions as the white version, but obviously with lower energy consumption:


Help spread the word… use (http://www.blackle.com)

[Fluff]

same goes for murc and facebook

Only makes a difference for CRT screens afaik.

[az]

Yep - though if ALL websites used negative designs with HIGH contrasts, we could turn down our LCDs' backlight by a few notches

Now imagine the CPU cycles saved if Google didn't use any graphics etc.

Also, it's not watts per hour per year, it's watt-hours (that's watts times hours) per year, Wh/a.

[rylan]

It makes a difference on LCDs also. Driving white uses more power than black, since you have to open the crystals for white. The normal mode for most lcd modules is black. The larger the monitor, the more savings as a result.

[High_Jumbllama]

No image search. . . . . If there was an image search I would try it for more than 2 minutes.

[az]

Rylan: It's not ALL LCDs though, is it? Even so, of course when over 50% of LCD area use this method, it'll save. But how much energy does twisting the crystals take, compared to the backlight or even an old CRT?

[rylan]

Actually all LCD panels for commercial monitor use that I know of are 'normally black' when the TFT layer is off or in low power. A normally white monitor would be brighter, but have substantial light leakage when black and have reduced contrast.
On a 1920x1200 22" monitor its around a 5W difference between a black and white screen so nothing huge. CRTs will be more, but not substantially since they are still actively scanning and most of the energy in a CRT is from keeping the magnetic coils energized.
Fyi, worst case energy use patterns on an LCD are usually a white/black checkerboard pattern. But still as you mentioned, most of the power usage is from the backlight.

[Nowhere]

http://userscripts.org/scripts/show/10819

(and under Opera: view -> styles -> high contrast (one of the two ); I'm surprised az haven't mentioned that )

[az]

Apple+Alt+ctrl+8 inverts the screen in the whole OS.

Or, of course, in Opera use a custom style sheet, as you said

[Brian Ellis]

I have just done a test with a 19" LCD monitor, current taken from power, brilliance and contrast for my normal viewing:

Totally black screen: 0.219 to 0.220 A
Totally white screen: 0.219 to 0.220 A
Standby: 0.029 A