Five Myths and Mysteries About Black Web Surfing
by Mark Ontkush, Boston, Massachusetts, USA on 08.12.07
You might have been following the recent debate about surfing a black web, even received a viral email or two on the topic. We have discussed some facts and figures around using a black Google, and other alternatives sites such as Blackle. In spite of all the recent press, mysteries and myths still abound, here are 5 of the most common.
1. Every monitor uses 74 watts to display a white background, and only 59 watts to display a black background.
Answer: Nope, and it's probably the biggest misconception. The original post that started this whole thing pulled these numbers from the US department of energy, but these numbers almost certainly refer to CRT monitors only.
2. Ok, well, every CRT monitor saves 15 watts then going from white to black.
Answer: The amount of energy saved here is depends on many factors, including the size, type, and manufacturer of the specific monitor. A study conducted in 2002, the infamous Roberson Study, found that different CRT monitors saved between 4 and 30 watts going from white to black, a big range. A new study by Techlogg on 4 CRT monitors found that they all did save energy, but the range was narrower and the savings was smaller (only between 7 and 11 watts). It is likely that CRT monitors are getting more efficient.
3. What about LCD monitors? I keep hearing that is makes no difference what color they display, or that they even use more energy displaying black over white.
Answer: Another big misconception. LCD monitors have a light behind the screen that is always on, so white is usually the most efficient color to produce; you just let the light shine through. Black on the hand requires the light to be completely blocked, and this takes energy. So, on the face of it, white would always be cheaper than black to create on LCD screens. Turns out this is mostly true, and on average, takes less than a watt of energy to do.
But there more, because some clever LCD manufacturers check how dark the screen is, and if it's very dark they dim the backlight; this saves energy. The Roberson study found this was true for every LCD monitor, Techlogg found it was primarily true for monitors over 24 inches wide. This doesn't save much energy, tops 4 watts, but it does save some. So, LCD technology has changed over time, and it is true that the differential between displaying white and black is much tighter than CRT monitors, a few watts at most.
4. Very interesting. So that solves it, since about 75 percent of the monitors in the world are LCD monitors, and since it doesn't really save a lot of of energy to display black over white (some even cost energy), the whole energy saving argument is a wash.
Answer: It is true that there are a large number of LCD monitors out there, and that for the majority of them it doesn't make a whole lot of difference energy wise to show black vs. white. Sites such as Techlogg and Infoworld used these numbers to demonstrate that the technique was ineffective.
In fact, this very argument proves that the technique works! The reason is that energy consumed by the LCD monitors is dwarfed by the massive savings from the other 25 percent of monitors, the power guzzling CRT monitors. If you want, you can try this experiment to convince yourself of this fact.
Get three lcd monitors and plug them into a power strip. Then get one CRT monitor, and plug that into the same power strip. Plug the power strip into your testing equipment, then plug that into the wall outlet. Now turn on all the machines and get them all connected to the Internet; show an all white screen on all of them, and take a reading from your test equipment. Now show an all black screen on all of them. Read your testing equipment again. You have two readings now, the second should be lower than the first.
For another explanation, read Pablo Paster's posting on the topic.
5. Great, so it works! Does it work on any site?
Answer: Yes, the energy saving principle will work on any site. Google is often referenced (they get over 500 million hours of use each year) but other good candidates would be Yahoo, MySpace, and YouTube. :: TriplePundit ::Infoworld
The problem is not whether, in aggregate, the technique saves energy. The problem, in the case of LCD monitors, is that folks are lulled into thinking they are doing something to save energy when in fact, they are doing very little.
[Agreed. Blackle should divulge this. mjo]
Furthermore, your post does not address the issue of reading difficulty on a black screen.
[Yes, but this is not directly related to energy use. An important point though. mjo]
One could argue that the amount saved in the case of LCD monitors is so miniscule that it does not warrant the amount of effort to educate about this. One's time would be much better spent getting people to unplug their computers when not in use.
[Disagree. No reason why you can't unplug your computer, and surf in bllack. mjo]
Facebook would be an awesome candidate, too.
I've already pawned this on Facebook but they've been Coldfacebook about it to me... probably because of their other pending legal troubles. :-)
Won't matter if it'll be black or white if it ain't on-line, right? :-)
I think I've read somewhere here why TH isn't black, but perhaps you'd want to tell it again to your readers since many of them among the many many probably spend a lot of time reading it like I do. Lots of great stuff here, that's for sure.
A cursory reading of this issue might lead you to believe that using black backgrounds are a way to save the planet. If you look at the blackle website, they claim some enormous amount of energy being saved. - - This is entirely misleading. Follow through on the included link to Techlogg.com. "Blackle makes next to no difference, on average, with LCD monitors." I measured the power usage on my monitor - absolutely no measurable difference. In my opinion, the black screens were much harder to read.
[yes, Blackle's wattage number is almost certainly exaggerated. mjo]
The 4th point in the above list seems to be arguing that this is a worthwhile effort even if it's only effective on 25% of the machines that are assumed to be using a CRT. I'd wager that the percentage of CRTs in use will continue to decrease - therefore any website redesign will have a decreasing impact on energy usage.
[true, but even at 1 in 10 its still worth it. mjo]
In summary: On my equipment, it makes no difference to use black web sites and I suspect that this applies to a growing percentage of people. We'd do better to apply our efforts elsewhere. Change a lightbulb to CFL, turn off a laser printer, change your thermostat... Just about anything will save more energy than using black backgrounds.
[what can I say? Nope. mjo]
I'll bet money that the increased average time spent reading a block of text on a black background uses more energy than could be theoretically saved. All of this is kind of ridiculous - the percentage of CRTs on the market is still dropping like a rock.
Something about that 75%/25% number: A lot of that 25% are in fixed-use systems, not systems that browse the web. A lot more are used by people who aren't net-savvy.
Dang, WHO CARES?
You guys are worrying about a few drops of energy when there are far larger things to worry about!
Why not concentrate on the big picture -- getting people to stop using old CRTs? *THAT* makes a HUGE difference no matter what page you're looking at!
My old CRT? 300W. Every minute of every day I spent looking at it. During energy saving it went down to something like 25W. Still a power hog even while it was off.
My LCD? 56W, when it's ON. When it's in power save it's something small like 5W.
Who cares if it's 56W when it's on a white screen and 57W when it's on a black screen? Point is that by switching screens, I'm using 1/6th of the energy NO MATTER WHAT I'M LOOKING AT!
If you're going to crow about something, crow about something significant! Sheesh!
[Actually, we usually do crow about things far more significant. However, since this story has received so much attention, we thought we would set the record straight. mjo]
I was scepticle about the energy saving to begin with. As far as I can see this is just another way for a company / individual to make some money by playing the green card.
Lots of companys these days are using the environmental saving as a selling point for things that they would have done / do to save money for them anyway! It makes them look good and they get extra customers and money at the same time.
In the case of Blackle it has the google ads on it and must be making vast sums of money from that (not just enough to pay the bandwidth fees)!
On a mac, you can hit Ctrl + Option + Command + 8 and it inverts the colors so that way you can view any webpage in black.
It seems like people forget the scale we're looking at. Although it may not really matter for me alone, just remember how many people are going to the web everyday. The US has 300 million people. Calculate savings over these numbers. I think this is the point with conservation. As an individual I don't have to do much, and it doesn't really change my life, but as a collective it makes large changes. I doubt people would think 5 more miles/gallon would be significant for every vehicle in the US.
Jesus people! don't you realize you're dealing with peanuts here? Why don't you go for bigger fish, such as those stupid SUVs people in America like so much. Or how about turning off the A/C when the weather is fine. I don't know the exact math, but I bet that if you turn off your A/C for about an hour it will save more energy than if you surfed black web pages for a lifetime or even several lifetimes. Think about it.
I'm inclined to use this simply because I'm bored of the traditional color scheme. If I'm even potentially saving energy while I'm at it, then I'm all for it.
Of course this isn't going to be the big change that will save the planet. If you want to use this technique, that's great, but my fear is that ignorant people all over this nation who suddenly want to feel responsible are going to switch their monitors to black, and then drive to Outback Steakhouse in their H3 and think, "At least I'm saving energy on my computer screen."
I checked into this stuff when my office wanted to be more "green." I bought a power meter and took my own readings. I found that an LCD used about 2-4 watts more displaying a white background then a black one. With a CRT it was much more dramatic. But in either case, a black background used less than a white one.
Hi. I agree that every bit counts. Have you considered turning this website predominately black?
I remember the fad in the mid-late 90's of using white text on black backgrounds...it was awful! My eyes still hurt thinking about it. Why don't we demand that manufactuers build more energy-efficient products instead of encouraging web designers to make crappy, unreadable sites?!
just change your color palate in IE to green on black...now every site you surf is energy efficient
Great Post. I've been following this issue with great interest and I too believe it would work. Looking for more about that topic I stumbled upon a google-powered search engine that already implements the black design: www.ecogg.com
is the power use by blackle servers at all factored in?
i mean, there have to be a few fairly substantial servers somewhere which remakes google into blackle, and that is drawing power. it probably doesn't swamp the benefits, as in the case of the amount of energy it takes to turn subsidized corn into biofuel (go go jatropha; http://www.treehugger.com/files/2006/12/biodiesel_in_in.php ), but it might make a difference in the marginal utility of black google...
of course, if normal google went black, then this becomes irrelevant.
I still use a Hitachi crt monitor - its 7 years old and works great. It has a great resolution - and I'm very comfortable using it. I realize that now the lcd monitors have dropped drastically in price - and I will replace it - but not till it dies.
I have been looking into more and more of these energy saving ideas lately.