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In the past, numerous methods have been developed for evaluating the
efficiency of a datacentre, for example the PUE factor, which we will present
briefly later on. Unfortunately this factor does not include any evaluation of
the energy used and, worse still, virtualising server systems, can even make
the PUE factor worse. A further criticism is that no distinction is possible, as
to whether renewable energy or energy from fossil or nuclear sources is
used. The need for a more holistic view is therefore clear; this is also taken
into account in the Carbon Usage Effectiveness (CUE), which was launched
by the Green Grid (TGG) Association
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and which we will look at later on.
What can you do as Cloud consumer to ensure that the Cloud you are using
takes a sustainable approach to using the resources of our planet?
What possibilities does the datacentre provider have to reduce its
emissions?
But let us start at the root of all evil, CO
2
emissions.
The problem with greenhouse gas CO
2
Because computers do not directly emit CO
2
in the course of their use,
emissions do not occur at the consumer's site. However CO
2
can be found in
the process of generating electricity and on the way in which energy is
produced. The energy supplier can choose from an abundance of energy
sources for generating electricity:
Fossil fuels: Coal, Gas, Oil
Renewable energy sources (RES): Hydropower, Photovoltaic or solar thermal
energy in southern countries, Wind power, Biomass, Nuclear energy
Depending on the technology, corresponding amounts of CO
2
are created
per KWh of electricity generated (unit grams of CO
2
per KWh). Ideally, when
renewable energy sources are used, this is 0 grams, or the CO
2
is
environmentally neutral if is produced from biomass. Where electricity is
generated by caloric power stations, using coal, natural gas or oil, this value
can increase to more than 1,000 grams per KWh. Nuclear power is also free
of CO
2
emissions but it entails many other risks which we will not cover in
detail here.
As you can see, your Cloud supplier's choice of energy supplier has a
substantial influence on the CO
2
footprint of the power provided. Depending
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