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Blackle.com boasts about how they save energy.

However I was watching a video (2:30 for the bit concerning my post) the other day with a professor showing how LCD screens work. That the backlit is always on and it works be varying the angle of the light from the backlight through polarised sheets. The varying the angle of the light is done by applying charge to some molecule or something.

The video says that to block the light passing through (to make the pixel black) a charge has to be applied. So surely if all the pixels have charges applied to them to make them black. Blackle is actaully using more energy than Google.

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closed as unclear what you're asking by Jacob Jan Tuinstra, Al E., Alex, Vidar S. Ramdal, jonsca Apr 3 '14 at 14:43

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

How do they save energy? What is your question? How does it involve Google? –  Jacob Jan Tuinstra Apr 1 '14 at 20:50

1 Answer 1

Google agree that an all black screen is likely using as much or more energy:


Scientific American also agree:


However, on smartphones with Super AMOLED displays, black areas of the screen DO use less energy, because the screen can selectively turn off the backlight behind darkened pixels. This is why the new Windows Phone 7 OS uses predominantly black panels:


So in summary, Blackle only really saves energy on some new smartphones.

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So really their statement, which was around before LED screens (well at least before anyone used them) is complete trash. –  Jonathan. Apr 12 '11 at 13:18

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