Carbon neutral email

I watched An Inconvenient Truth last weekend.  Aside of learning how great of a person Al Gore is (according to himself), it got me thinking about how much power our data center uses, the carbon dioxide that is released into our atmosphere to produce the power and how much it would cost to offset that CO2.  So I ran some numbers…

My assumptions:

  DEVICE               WATTS
  Motherboard           25
  AMD Athlon 64 3200+   89
  AMD Opteron           85
  PC133 SDRAM           12
  IDE Hard Drive        25
  SATA Hard Drive       25
  NIC                    4
  CPU Fan                3
  System Fan             2

We have several different server hardware configurations, but with a few shortcuts they can all be classified into three types…

  Type A: 191 Watts
  Type B: 272 Watts
  Type C: 241 Watts

In our Dulles VA data center, we have 90 servers of type A, 5 of type B and 69 of type C.  That equals 35,179 Watts.  But there’s more… According to Cisco, servers account for 26% of the power consumption in a typical data center.  The remaining power is consumed by networking equipment (11%), power conversion losses (10%), lighting (3%)  and cooling (50%).

This yields…

  Servers   26%   35,179
  Network   11%   14,883
  Cooling   50%   67,652
  Lighting   3%    4,059
  Loss      10%   13,530

  Total =  135,304 Watts

  Converting to kilowatt-hours (*24*365/1000) = 1,185,263 kWh

We host 400,000 mailboxes in the Dulles data center, so that means each mailbox consumes 2.9631576 kWh each year.

So if you want to have carbon neutral email, just multiply 2.96 kWh by the number of email accounts you have with, and plug that number into a carbon offset calculator such as the one at  Then donate the amount they say.  Your donation will go to the production of renewable energy, reforestation and/or energy efficiency projects.  These projects have the net effect of canceling out the CO2 produced.

According to my rough calculations (and please correct me if I made any errors or incorrect assumptions), our customers can offset the CO2 emissions created by each email account for just under $0.01 per year.

You’ll need to look at offsetting more than just your email accounts if you want to save the world.  But it’s a start.

One thought on “Carbon neutral email

  1. Andrew

    So, if raised its prices by $0.01/yr. per mailbox (or ate the penny itself), you could be a Carbon Neutral company? That might have some positive PR value…


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