Sunday, January 21, 2007

Save 3,000 Megawatts a Year

From this post by Mark at EcoIron we decided to create this custom Google search engine. It will search the internet through
As noted, an all white web page uses about 74 watts to display, while an all black page uses only 59 watts. I thought I would do a little math and see what could be saved by moving a high volume site to the black format.

...the shift to a black background will save a total of 15 (74-59) watts. That turns into a global savings of 8.3 Megawatt-hours per day, or about 3000 Megawatt-hours a year.
  • Per capita annual electricity consumption (MW-hrs) in the U.S. in 1997: 1.213
  • LCD monitors do not reap the same energy saving benefits.


  1. Wow I,m impressed tried a few searches, and lo and behold all in black.....

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  3. We created a screensaver that kind of fits with this for WWF's Earth Hour (The Sydney CBD - Australia - will turn its lights off for an hour 31 March - 1,000+ business and 60,000+ individuals have signed up to get involved). Anyway check the link:

    I discussed this article with Google Sydney. Thanks for the inspiration!

  4. Thanks for the notes - I'd no idea what a megawatt-hour actually meant!

  5. WIB: Web In Black
    1 - Firefox > Tools > Options...
    2 - Contents > [Colors...]
    3 - Configure yours Colors options like this:
    Text & Background
    text: [grey]
    Background: [Black]

    Link Colors
    Unvisited Links [blue]
    Visited Links [red]

    [Disabled] Allow pages to choose their own colors, instead of my selections above

    [OK] an Enjoy ;)

  6. This is lame, you aren't going to save anything if you are using an LCD. And I seriously doubt you will save anything on a CRT either.

  7. I could be wrong, but this looks suspiciously like Bad Science. Let's see the math. Even assuming the CRT power ratings are correct, it must include:
    1. The number of LCDs vs CRTs in use
    2. LCD power savings (if any)
    3. Average percentage of screen covered by browsers (not everyone runs maximized)
    4. Average time that the google-black window is on top
    5. Average time that the computer is even on

    Everyone's a hero in their own blog.

  8. Thanks for that i think the blackle concept is well cool. Recently while surfing i also found blackle games; interesting concept: play games and save the world!! lol

  9. Your energy ratings seem low, My girlfriend has a crt (19 inch) and it consumes about 180 watts (on the info panel). My widescreen 20 inch lcd uses about 90 watts.

    considering all that, this google black shgould have been done years ago, not when everybody is changing to an lcd.

  10. the way how to lcd works it's completly different to the crt monitors this math doesn't works in this case... then how many how many hours do you think that is going to be turned on the google page?

    Bad Science

  11. So having everyone in the world switch to google black (or Blackle... blackhole) willl only save as much energy as 2,473 US people use in a year? (3000/1.213 = 2473) That's hardly anything! That's like 0.0007% of the US population (330 million). (2474/330000000 = 0.000007) That's such a minescule amount! I mean more than 0.0007% of the population purchase a second LCD monitor to use anyways so they can have dual screens.

  12. thank you so much :)
    save my eyes and save our world.

  13. ummm grt .... no words 2 sayyyyy!