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When I was at the Uptime Institute's annual conference a few years back, the title of this post was a sort of catchphrase everyone was using. It made sense to me then. Of course it takes more to actually create an electron than anything we do with our power generation technology. That is getting lost in the weeds of technical reality versus a kind of handy concept. Not all electrons are created equal is a nifty turn of phrase and contains the key concept: it matters how you push electrons up the wire.


Later, when I was researching CO2 emmisions of each of our major R&D data centers, the point came home for me. The first thing was simply just how much CO2 we are talking about in the first place.


Pounds of CO2 per KW / Hour


When I am doing all the math around a data center, the first thing I almost always mess up is watts versus kilowatts. The second is whether I have already converted from pounds to tons or not. Every input you get out there from the various data sources come expressed in some locally logical way, and keeping everything in the same unit has led to stupid mistakes over and over. Most recently when talking to the above mentioned Uptime Institute, I dropped something in as pounds, and expressed it as tons, but forgot to add the divisor into the spread sheet to convert it. Delusions of grandeur, to be sure. To compound it, in another place, I was trying to express in pounds, but labeled it as tons.


This is how you lose Mars orbiters.


So, back to basics for a second: how much CO2 is created to generate one kilowatt for one hour? That turns out to be not as straightforward as one would hope. Looking at the US Department of Energy website (, they list the following values for the major carbon sources:



Pounds CO2 per kWh:

Coal     2.117 - 2.095
Petroleum     1.915 - 1.969
Gas     1.314     1.321



I try to imagine what a pound of CO2 looks like, and of course it is fairly easy to think of dry ice, and what a pound of that looks like, but as a gas it expands out to a far large volume of space. A gram of dry ice is about 1.5 grams per milliliter  (1.0 × 10-6 cubic meters), but CO2 gas, at 20 C and 1 ATM, is about 1.8 grams per cubic meter. Big difference. Big surface area.


Each of those sources listed above would then make quite a difference in terms not just of the weight but the sheer volume of space that CO2 would expand out into. Ultimately of course it is diluted into the atmosphere and then thought of as a percentage of the gas mix, or expressed as Parts Per Million (PPM). PPM is the way NOAA reports things. According to NOAA, we saw about 3.3 ppm increase in CO2 in the atmosphere the last year (2012-2013). There seems like a lot of air up there, but that is partly perspective. Here is another one


Looks pretty thin there.


Carbon as an element is only about .5% of the total makeup of our planet. CO2 gets some size leverage because it joins up with two of its oxygen buddies, and while carbon is only 6 on the periodic table, its two cohorts in the molecule in question are 8, for an extra bump in size. This is how burning small things to make kilowatts creates relatively large poundage of CO2 output... but I digress.


Other Power Sources


Just so it is clear I have not skipped over and/or not given some thought to this, how power is generated goes beyond the three carbon-based methods above. Hydro, or wind, or wave, or geothermal, or solar or even nuclear are all generally considered to be zero CO2 emitting power sources. Like my post here at Green IT about concrete points out though, clearly these methods of power generation are not completely zero. It costs something in CO2 to make a water dam or a wind tower or whatever. It costs more CO2 to move the generation technology from the factory to the place where it will be used (and concrete for a water dam for example is very CO2 intensive to create, and very CO2 intensive to move about).


Entropy means that all power generation sources will need to be maintained, which of course means more CO2 somewhere along the way.


Overall though, they are such a tiny fraction of the of the power that is being created that it rounds down to near zero-ish.


To be fair, the same thing holds for a coal fired plant, or a gas generation plant. CO2 was used to create it too, unless the manufacturer is 100 percent on a zero emission power source.


Zero Emissions in Other Ways


There are other ways to generate electricity that have good CO2 math. Things like putting a methane collection dome over a garbage dump, and burning that to create power. Not zero CO2, but better than letting methane hover about. CO2 is a greenhouse gas, but methane (CH4) is a 20 times more powerful one.


Plant something organic, like a tree, burn it, and plant more to replace it, so that you are always absorbing more CO2 than you are emitting. Net Zero emmisions. Go negative even, by absorbing more than you release. I just listened to a very interesting TED talk about ways to reclaim desert and offset all the CO2 we are emitting.. using grasslands and animal herds the other way around from how we have been.


Point is: It matters how power is generated when discussing the CO2 we put into (and leave in) the atmosphere.


BMC does not build cars or houses. We build software. Our power usage is tied to our data centers used to create that software. The data center is our manufactoring plant, so how that data centers electrons are being shoved into it is key to how much CO2 we are indirectly (via the power plant) placing into the atmosphere.


Where and How


This is 2009 DOE data, but I just looked at Texas for 2010 (the latest on the web site) and it is not that different other than that Texas passed 10,000 Megawatts of wind generated power recently (July 2012 report). It is the first state to do so. I have been out in West Texas many times to see those farms. Amazing.


Where and therefore how power is generated adds up to quite a bit of difference in the total amount of CO2 the power generation adds to the atmosphere. Here are four examples:




Total Net Electricity Generation
9,928 thousand MWh
Petroleum-Fired - 00.03%
3 thousand MWh
Natural Gas-Fired - 27.8%
2,768 thousand MWh
Coal-Fired - 38%
3,778 thousand MWh
Nuclear - 28%
2,782 thousand MWh
Hydroelectric - 05.6%
552 thousand MWh
Other Renewables - 00.3%
29 thousand MWh

There a number of interesting solar projects in the works in AZ, like Solana and Agua Calente that will be changing this mix with time. Also interesting is that PG&E in California has a contract to buy the power generated by Agua Caliente, which explains these numbers:




Total Net Electricity Generation
16,861 thousand MWh
Petroleum-Fired - .04%
7 thousand MWh
Natural Gas-Fired - 36.4%
6,144 thousand MWh
Coal-Fired - 1%
184 thousand MWh
Nuclear - 19.3%
3,269 thousand MWh
Hydroelectric - 26%
4,379 thousand MWh
Other Renewables - 15%
2,528 thousand MWh




Total Net Electricity Generation
39,989 thousand MWh
Petroleum-Fired - .015%
6 thousand MWh
Natural Gas-Fired - 47.6%
19,061 thousand MWh
Coal-Fired - 35%
14,142 thousand MWh
Nuclear - 9%
3,613 thousand MWh
Hydroelectric - .25%
100 thousand MWh
Other Renewables - 6.5%
2,617 thousand MWh





Total Net Electricity Generation
3,869 thousand MWh
Petroleum-Fired - .49%
19 thousand MWh
Natural Gas-Fired - 62%
2,429 thousand MWh
Coal-Fired - 18%
697 thousand MWh
Nuclear - 12.6%
489 thousand MWh
Hydroelectric - 2%
82 thousand MWh
Other Renewables - 2.7%
106 thousand MWh


Putting It Together


It is interesting to note above just how little power comes, in those states, from petroleum fired generation. I picked those four because in North America, that is where BMC has a good sized R&D data center, and therefore where we, at some scale, consume power / generate CO2. How much CO2 per kWh you ask? Based off the major carbon intensive sources:




- Coal 38.00%

- Gas 27.00%


1.149 pounds CO2 per kWh




- Coal 1.00%

- Gas 36.40%


0.4942 pounds CO2 per kWh




- Coal     35.00%

- Gas 50.00%


1.385 pounds CO2 per kWh




- Coal 18.00%

- Gas 62.00%


1.184 pounds CO2 per kWh


The 2011 data should be out soon from the DOE, so I'll need to re-do these numbers. It is still interesting to me as a relative comparison to see how much different this is from state to state.




As different as these are, another thing that matters is the ability to conserve power usage, or perhaps, looked at another way, to use power more intelligently. If I use 1 kWh in Texas, and 2 kWh in Massachusetts to achieve the same end result, then I emitted more CO2 overall in Massachusetts, despite the lower CO2 per kWh there.


That is where I'm going to go next post.