I can see from my hit counter that Black Google is making the rounds again. It's interesting; this is the third time the Black Google wave has crashed over the world. Since some of the facts get tangled every time, I thought I would do a little Q&A on the topic.
Q: Are the calculations in the original post correct?
A: Yes, the calculations are correct, Black Google would save 750 MWh a year. Thousands of people have reviewed the calculations - they are right.
Q: But some sites are reporting a 3000 MWh savings...
A: The original calculations were not correct because I assumed that the power savings was for every monitor, and in fact this is not true. This is a viral mistruth, probably caused by the fact that the original link still has '3000' in it. 750 is the number.
Q: You are talking about the LCD monitors right? They have a backlight that is always on, and use the same amount of energy or even a little more to show black. You have to exclude them from the calculations.
A: That is correct, using Black Google makes little or no difference when you have a LCD monitor. This was set straight almost immediately, but there are still tons of postings and comments on this issue. It's has been common knowledge for months. The 750MWh number reflects this fact; Black Google still saves energy.
Q: So, in a year or two the whole thing will be pointless because CRTs are going away.
A: They are being replaced, but as of 2006 25% of all the monitors in the world are still CRTs, and that number goes up for China (50 percent) and South America (75 percent). Also, there are new technologies such as plasma and OLED where white costs money - these technologies are on the rise so we will be right back in the same boat. And there are handheld devices as well, battery operated where power is a bigger deal.
Q: So, 750MWh is the right number?
A: No, it's higher now! Pablo Paster did some recent calculations and the savings is up to a conservative 1500 MWh. The reason is that Google is getting more traffic, and that he counted page hits while I just counted queries.
Q: So Google took your advice and created Blackle? Good for them!
A: No, Blackle is an independent site runs by HeapMedia. There are quite a few out there now, including Earthle, Greygle, GreenerGle, one at blogspot, Ninja, Trek Black, Spanish Black Google, and German Black Google. But my all time favorite is the guy who made the mega site of bible studies based on a misspelling of one of these engines.
Q: It hurts my eyes to use Black Google - white on black is the most natural.
A: The white on black palette was probably just adopted from the paper printing world, and there have been several studies (many from the 80s) on what the best color scheme is. I've heard white on grey, green on yellow, white on green, green on black, amber on black, and white on black. I think the jury is still out.
Q: Why doesn't every big site adopt a black blackground - MSN, Yahoo, Amazon, etc.?
A: Why doesn't every big site do this?