139
on its geographic location, the operator may be dependent on certain
energy suppliers who consequently emit a corresponding quantity of CO
2
.
For an understanding of CO
2
volumes, the table below shows an excerpt
from a study by Greenpeace with values for suppliers in Austria from the
year 2007. You can read the current value of your energy supplier's CO
2
emissions off your current energy bill.
Versorger
CO
2
‐
Emission pro kWh
Bewag
0
VKW
130
Tiwag
170
Kelag
183
Energie AG
199
Salzburg AG
271
Wienstrom
276
Steweag‐Steg
277
EVN
293
Of course, Cloud providers can leverage geographical benefits by their
choice of location, as we will see in a moment; however, every location
involves a compromise.
The ideal datacentre sites are Florida, Greenland, and Ireland. Why?
Florida for the staff, Greenland for cooling and Ireland for the taxes.
Unfortunately, there isn't a location where the three ideals coincide.
Let's get serious: Microsoft chose its datacentre site not only because of the
lower taxes in Ireland, but also for the ability to use "free‐to‐air cooling" for
nearly 365 days a year. Because Irish air rarely reaches a temperature above
25
°C, it is typically possible to do without the use of energy‐consuming
refrigeration equipment. But this air can't just be blown through the
datacentre, it has to be conditioned, and prepared for the use in hand. This
means humidifying or dehumidifying, depending on the weather, and of
course cleaning, both of which are processes that consume energy.
The location and energy source play a crucial role in the expected CO
2
emissions. Both of these are factors that Cloud consumers cannot directly
influence, however, they can be taken into account in your choice of
provider.
