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."

Comments

Re:No savings on LCD:s

[TheThiefMaster]

In fact don't TFTs use marginally more energy to display black?

Re:Black background?

[Asmodai]

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

Depends on the kind

[Sycraft-fu]

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.

Re:silly

[TheLink]

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 :) ).

Some real figures

[David Off]

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.