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Change Google's Background Color To Save Energy?
i_like_spam writes "Recent commentary at Nature Climate Change describes an on-going debate about the energy savings associated with the background colors used by high-traffic websites such as Google and the NYTimes. A back of the envelope calculation has suggested energy savings of 750 Megawatt hours per year if Google switched their background from white to black. In response, a new version of Google called Blackle was created. However, other calculations by the Wall Street Journal suggest minimal energy savings."
In fact don't TFTs use marginally more energy to display black?
Most new monitors are LCDS. LCD's are generally backlit and black is achieved by having all the pixels opaque. So wouldn't black cause a higher power usage? or just break even?
"There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy."
From what I remember reading in some research is that a light grey text on a black background actually produces one of the best readable displays for your eyes.
Anyway, interesting read: http://www.writer2001.com/colwebcontrast.htm
Jeroen Ruigrok/Asmodai
TN+Film ones, by far the most common, do. They have to be energised to go black, their no power state is open which is why the pixels fail to white. VA (P-MVA, S-PVA and so on) and IPS (S-IPS and such) don't because their no power state is black and have to be energised to open and thus fail to black.
Regardless the energy used on the panels isn't much in comparison to the backlight. That's why companies toy with reflective displays (like the old Game Boy Advances). It does really well for battery life when there's not a backlight. That's what sucks the energy.
In a decade or two it will probably all be e-ink based so there will be no difference. Except it would need to be illuminated in the dark.
Unless they make a hybrid with oled in the dark and e-ink in the light. Then a light background would waste electricity at night and strain your eyes more.
So have a dark background at night and a light background during the day like reading paper, that's it, web pages that adjust their display depending upon your surroundings.
Maybe I should have kept that to myself...
I would think a nonbright monochromatic colour (say dark/medium green) on black would be better than grey on black. Then you don't get chromatic aberration even if you have crappy eye wear/lenses.
BUT, nowadays lots of things are multicoloured anyway and the text is often next to pictures as the article you linked mentions. Having pictures in a mostly black screen might be more "jarring".
Some LCDs have dynamic backlights. So if they are displaying something dark they dim the backlight down.
:) ).
So when comparing the contrast of LCD displays find out whether contrast ratio are measured the same way.
e.g. whether it's dynamic or static.
Whether it's the ratio of the brightest white vs the darkest black AT THE SAME time on about the same part of the screen (some can dim different parts of the screen to try to suit the dark bits of the picture),
or it's the ratio of the brightest white now vs darkest black 1 minute ago - no adjustments of brightness levels.
or even the ratio of the brightest white the monitor can display, vs the darkest black the monitor can display when on, with adjustments allowed (really cheating
I've just tested this on a Sony 15" LCD monitor (M51?).
Google.com: 18.5 watts
Blackle.com: 19.5 watts
Slashdot: 19 watts
so it would seem that using blackle is using about 5% more power.
Firstly, if you're using a CRT all day with a white background, then you have an electron beam lighting up phosphors and thus beaming light straight at your eyes all the time you're looking at it. It's like staring directly at a light bulb if you have to use the PC for any length of time.
Secondly, if you're using an LCD, it's likely backlit by a very bright bulb. "White" means opening the LCD molecules and letting that light through. So, in fact, you ARE staring at a light bulb when looking at a white LCD screen.
Computers Screens are not paper. They have light coming from them and hitting your eyes.
Paper products have light reflected off of them, usually at much lower intensity to start with.
So reading dark letters on light backgrounds is fine for paper.
But on a TV Screen, it's *provably* better for your eyes to have dark backgrounds and light lettering. If this hurts your eyes, use wider fonts instead of razor thin lettering.
- Give a man a fire and he's warm for a day, but set him on fire and he's warm for the rest of his life.