Sometimes it’s hard to see the forest for the trees. For example, April’s federal and Ontario government decisions to ban the sale of incandescent light bulbs struck me as a bit of a drop in the bucket when compared with other changes that could be made to save energy, such as turning off lights in office buildings overnight.

The value of small changes is well illustrated, though, with the introduction of Blackle. According to the site’s “About” page, Blackle was inspired by a January blog post calculating the energy used by a white screen versus a black screen:

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.

Three thousand megawatt-hours a year. That’s no small amount. Motivated by this big number, Blackle was set up by Sydney, Australia’s Heap Media as a search page powered by a Google custom search.

Unfortunately, the two queries I tested it with turned up different results than the same google.com or google.ca search. (One was “pronger suspended,” the other “incandescent light bulbs ban.”) I’m not sure what accounts for the difference. Maybe it’s the Australian factor. Nevertheless, Blackle demonstrates original thinking on the day-to-day problems of climate change.