Power consumption of monitors with black vs white backgrounds

I heard some time ago about some claims that google should use a black background instead of white, to save power on everyone’s monitors. It sounded somewhat reasonable when everyone still had CRTs, but I was always curious just how much power it would really save.

So, I hooked up one of the energy meters here to my monitor, and displayed a fullscreen black on white terminal, and then a fullscreen white on black terminal. And then back and forth a few times.

  • Black screen power usage: 0.188 Amps (@240V)
  • White screen power usage: 0.175 Amps (@240V)

How about that. On my monitor at least, (A Benq G222HDL, a fairly generic LED screen) the black background actually uses more power.

The computer itself uses far more of course, and the idle printer/scanner uses 0.051 Amps by itself, so there’s far more savings in switching off than in changing background colours.

Of course, I’m not the first person to question these claims…

  1. It depends how the black is generated on your LCD (yep LCD, LED is just the backlighting) monitor. If the RGB transitors in each pixel block the backlight in their idle state, then a black background would use less power, but if the transistors are transparent at idle you get white. Now if it were a true LED display, the black screen would definitely draw less

  2. Apircepation for this information is over 9000-thank you!

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