Black Google Would Save 3,000 Megawatts a Year

[fireandrain]

An all white web page uses about 74 watts to display, while an all black page uses only 59 watts. See what happens when you do the math on Google's home page. Astounding.

http://ecoiron.blogspot.com/2007/01/...megawatts.html

That's pretty amazing if it's true

[include]

Only CRT displays use more energy to display brighter things. For everything else, it is completely false that a black display uses less energy than a white page. The backlight on an LCD is on for the entire LCD regardless of what is being shown. The black pixels are only black because the LCD blocks out light. Same with projectors, etc. The article is thoughtful, but invalid.

Correct me if i'm wrong, but wouldn't an LCD use slightly *more* power to display black than to display white? To display white, the liquid crystals just have to be at their normal state. To display black, voltage needs to be applied to the pixels. The backlight is on full blast either way, so black would just add to the power draw.

[mickb]

Hi everyone

Just joined here, mainly because the brief browse of your forum was interesting but frustrating.
Firstly what I am typing is black on a white background and I am using a crt monitor which means more power (not sure about LCD etc).
This forum discusses mainly renewable fuel sources but it seems little about the real future which in my opinion is fuel efficient devices.
We are planning on destroying the environment with giant wind turbines simply because we can't curb our ways or reduce electricity consumption.
The question is what are we trying to save. The answer is our extravagant
lifestyle.
Energy saving bulbs have made some difference, insulation has helped and I am sure many other steps have improved matters.But the focus is always on producing more.
Most electronic devices today run on low voltage ie 12v 5v 30vdc etc while the primary voltage on the transformer is 240 ac. do we really need 240ac for these things. LED lighting has come to the fore and is sufficient to light a corridor in an office block.
My local council has approved planning for two large semi's to be converted to one house.Unfortunately the owner is very vain and has halogen lighting illuminating the outside of his house 24 hours a day about 6 x 500w lamps.
What about street lighting with motion sensors, timers on domestic appliances etc, financial penalties for blatant energy wasters.
This is a mind set and can be learned from birth.
There are still factories dumping waste heat into the atmosphere when it could be used to reduce heating required elsewhere
PS
more when I think of it

Michael

[include]

Interesting piece here on this issue.

http://sciam.com/article.cfm?chanID=...8158F1CCD20C80

[altyfc]

I don't know whether a white or black screen uses less energy, but here's another thing to consider...

They say that pages with light backgrounds are easier to read. If they are easier to read, people can probably read them more quickly, and get the information they want in a shorter timeframe. So maybe it's actually better to have a white background for that reason?

[robin82]

Defiantly true about it working with LCD's. Black background wouldn't affect the back light, and probably would take more power in straightening the crystals (hadn't thought of that)!

altyfc, I like your idea about speed of reading the page. A lot of people (especially people with dyslexia) can read better with a lightly coloured background, such as light yellow or green, rather than pure white.

(the pastel green background of The Environment Site is a great example!!)

Robin

[oztrailrider]

There is a better way to save electricity than by using a black version of google, while it does seem to make a small difference according to the article below it seems to be much more beneficial to simply turn the brightness of your LCD monitor down. I came across this piece of information in a review of home power meters here: http://www.dansdata.com/quickshot041.htm.

As I explained in the letters column, the 30-inch Dells like my 3007WFP-HC may have a 147 watt power rating, but that only applies when they're running at their rather painful maximum brightness. You don't need - or even want - your monitor to be that bright if you're not using it in a very bright environment; it's just burning watts and straining your eyes for no gain at all.

In my office, I run my monster Dell at its minimum brightness.

At this minimum brightness, my new power meter reckoned my monitor was consuming only seventy-something watts, depending on what was displayed on the screen. An all-black screen was somewhere between 67 and 70 watts; an all-white one was about 77.

Winding the brightness up to maximum boosted the all-black power consumption to 133 watts, with an all-white screen now consuming 142.

Even if these numbers aren't very accurate, it's still clear that the power to be saved by using darker screen colours, or the silly "Blackle" black-Google site, is completely dwarfed by the power you can save by running your monitor at a lower, and probably ergonomically superior, brightness. It doesn't hurt to save the single-digit watts that darker screen colours can achieve, but the difference between the most I could make the monitor draw at minimum brightness and the least it drew at maximum brightness is more than fifty watts.

A heavy computer user could easily save a hundred kilowatt-hours a year just by doing this. That's not actually going to save you a whole lot of money unless your local electricity tariffs are unusually high, but it's nonetheless a quite impressive amount of energy.

[sparky]

Google did this themselves for Earth Day yesterday.