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
In January 2007 a blog post titled Black Google Would Save 750 Megawatt-hours a Year proposed the theory that a black version of the Google search engine would save a fair bit of energy due to the popularity of the search engine. Since then there has been skepticism about the significance of the energy savings that can be achieved and the cost in terms of readability of black web pages.
We believe that there is value in the concept because even if the energy savings are small, they all add up. Secondly we feel that seeing Blackle every time we load our web browser reminds us that we need to keep taking small steps to save energy.
“2002” yep CRT monitors use more power for white than black. The thing is LCD monitors (which I’ve used exclusively since 2001) take more power to display black than white. In order to display “black”, the lcd must turn the change the pixels from clear to black. The amount of light created by the backlight doesn’t and can’t change. LED backlit displays are different, but they’re not widely used yet.