The world famous page of Google is in white and according to the creators of Blackle, putting this page in black would save thousands of watts per hour worldwide.
But according to this page from the Wall Street Journal, energy savings by generalizing this idea would be minimal. Let’s have a look at facts and make up our minds.
In response to a page from my colleagues at WSJ.com’s Energy Roundup blog, I looked into the numbers. The federal Energy Star program, which encourages consumers to cut their energy consumption, had someone do a quick test for me and found that modern LCD computer monitors don’t see much benefit from a black screen.
But the Google cache version of the site’s “about” page, which carries some white screen space from Google atop the black page, explains that the site was inspired by a post this past January on the blog ecoIron claiming that if Google went all-black, it could save 750 megawatt-hours a year (a megawatt-hour is one million watt-hours; you can convert these to each other and other energy units here).
But as ecoIron noted, the savings are most likely to accrue from older CRT (cathode-ray tube) monitors, rather than the more-modern, more-compact, more-energy-efficient LCD (liquid crystal display) screens that have come to dominate the market (representing three quarters of all monitors world-wide as of last year, by some estimates).
Personally, I am not a huge fan of web pages written in black. Even if the lines I am reading are interesting, I am somehow ill at ease and not comfortable. And as the article states, most of the savings would occur on CRT screens which are nowadays less and less used.
Furthermore, I am not sure that reading only pages in black is good for eyes. I have no idea of what would say ophthalmologists about that, but would like to know their opinions on this matter.
So my conclusion on this particular topic would be to adjust the brightness of your screen in order to have the best quality of image and the minimum energy consumption.
Blackle will hence remain for me an oddity where I’ll research on Paint It Black, the famous song from the Rolling Stones.
Please also note that I previously wrote an article on the consumption of computer screens, ” A look at the electricity consumption of LCD screens “ which was published on Thursday, May 10th, 2007.
My main finding there was that LCD screens are consuming nearly half energy as a CRT screen of the same size.