Estimate of potential Sun Ray impact on Kyoto targets

Whenever the Kyoto agreement is in the news I think of my short visit to that beautiful city. I also think about how unfortunate it is that politics can prevent things from getting acomplished. The Kyoto agreement has some significant flaws1, but that's no excuse for ignoring the problem. So I started to think about some of the simple ways of conserving energy I learned after moving to Ireland. I'll post them here when I get a few together. But right now I just wanted to share another quick back of the envelope calculation comparing PCs and Sun Ray clients.

I'll apologize ahead of time for mixing english and metric units and for the very rough calculations, here goes. A modern desktop PC consumes about 70W when idle. CRT monitors add another 60W, so the total would be 130 Watts. Sun Ray 170s use about 40 Watts, so you're looking at a 90 Watt savings over the PC+CRT.

90W \* 8hr/day \* 365.25 days/year = 262980 Watt hours or about 260 Kilowatt/hours per year. A typical coal power plant puts about 2 pounds of Carbon Dioxide (CO2) into the air for every kilowatt-hour consumed.2 So for each desktop PC we replace with a Sun Ray, we could save 520 pounds of CO2/year. There are about 575 Million PCs in use worldwide of which at least 100 million are in the United States. So...if we could replace all desktop PCs and CRTs with Sun Ray 170s:
(100 million PCs \* 520lbs CO2/PC)/2000 lbs/ton 
                = 26 million tons of CO2/year in the U.S. 
Worldwide it would prevent 150 million tons of CO2 from being released each year.

Yes, it's a very rough order of magnitude estimate, but it sure looks like Sun Rays could make a dent in the Kyoto targets. I didn't even calculate that the cost of cooling nearly doubles the consumption estimate for each PC. My upgrade to a Sun Ray 170 didn't noticibly slow the oil consumption counter on, but it's a step in the right direction.

1One of the weirdest flaws is that Kyoto doesn't consider the effects of local climate. Warm winters have actually reduced U.S. energy consumption in the recent years and put the U.S. closer to its unsigned proposed targets than many signatories. Another is that Kyoto encourages industries to move from CO2 efficient economies such as Denmark to less efficient "coal burning" economies in the Kyoto-exempt world. While this might help level the worldwide economy, it could actually increase global CO2 output.
2 "Clean coal" usually refers to the reduction of NO2, SO2, Mercury and other toxic pollutants. The U.S. environmental protection agency doesn't currently consider CO2 as a pollutant. So-called "clean coal" usually produces just as much CO2 as dirty coal.

Update:I've corrected the original number based on the 40W typical consumption of SunRay 170s. To get the original numbers you'd have to turn off a reading lamp too.

Per SUN's latest Sun Ray 170 datasheet, 40W typical power consumption. I have observed that most 17" LCD monitors require 35W of available power. My 'project' kept me up last evening refining a method for mounting more sizes of power efficient LCD ware, DONE! Today's G8 meeting with SUN participation is GREAT news for this 'green' planet. 'Brat's' truly are excellent eating!

Posted by William R. Walling on July 06, 2005 at 06:14 PM GMT+00:00 #

Good catch, I knew there was something wrong with the original figures. I recalculated based on 40W typical power consumption.

Posted by bnitz on July 07, 2005 at 01:20 AM GMT+00:00 #

While your numbers are interesting, they don't seem to account for the fact that those Sun Rays are going to require servers to actually run them.

Let's pretend that you can operate, on average, 30 Sun Rays per one V240 (storage, applications, backups etc. included). How much pollution is the back-end of this Sun Ray system going to put into the atmosphere?

Posted by David Mackintosh on July 08, 2005 at 05:56 AM GMT+00:00 #

This would lower the savings somewhat but not as much as you would think. Especially considering that most of those 575 million PCs already require at least one mail server, nameserver, LDAP, file server, web server... Even if these servers are nearly idle most of the time, they're still using power. Someone else can work it out!

Posted by bnitz on July 08, 2005 at 06:49 AM GMT+00:00 #

My point was that even ignoring all those other external services, just replacing PCs with Sun Rays without factoring the additional pollution generated by the required back-end artificially inflates your savings. Of course, if we didn't have the back-end computers, we could just turn all the Sun Rays off and enjoy 100% pollution savings.

Posted by David Mackintosh on July 08, 2005 at 07:14 AM GMT+00:00 # If 30 users is typical for a base system, subtract 12W/user from my rough "Sun Ray savings" estimate, or turn off a nightlight/unplug a wall wart. I guess my main point is that there is significant potential savings here.

Posted by bnitz on July 08, 2005 at 07:59 AM GMT+00:00 #

We each agree that existing IT infrastructure uses too much energy! Let's work together on minimizing negative IT impact, such as energy usage, on this planet. Perhaps we will soon witness such efforts. :)

Posted by William R. Walling on July 08, 2005 at 05:21 PM GMT+00:00 #


Posted by guest on August 28, 2005 at 09:51 PM GMT+00:00 #


Posted by guest on August 28, 2005 at 09:52 PM GMT+00:00 #


Posted by guest on August 28, 2005 at 09:52 PM GMT+00:00 #

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