The Drew Blog

Blackle Power

Got a tip from Victor (AllDayBuffet.org) about Blackle.com, a clever response from Heap Media to a blog post by Mark Ontkush that calculates how much energy would be saved if Google switched its background color from white to black. Even though this savings only applies to CRTs (if you have a laptop or stand-alone LCD screen then this doesn’t apply for a technical reason I can’t really explain), the global savings would actually be significant (about $75,000 per year). Here’s a little more background on Blackle:

Blackle was created by Heap Media to remind us all of the need to take small steps in our everyday lives to save energy. Blackle saves energy because the screen is predominantly black. “Image displayed is primarily a function of the user’s color settings and desktop graphics, as well as the color and size of open application windows; a given monitor requires more power to display a white (or light) screen than a black (or dark) screen.” Roberson et al, 2002

Kudos to Heap Media for making this happen and Google for not shutting it down. It may not amount to a huge amount of energy saving but it is another example of how a little effort by a small group of people can have global impact.

NOTE: Here are the details of Mark Ontkush’s analysis from way back in January:

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.

Take at look at Google, who gets about 200 million queries a day. Let’s assume each query is displayed for about 10 seconds; that means Google is running for about 550,000 hours every day on some desktop. Assuming that users run Google in full screen mode, 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. Now take into account that about 25 percent of the monitors in the world are CRTs, and at 10 cents a kilowatt-hour, that’s $75,000, a goodly amount of energy and dollars for changing a few color codes.