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doesn't really make a contribution towards energy efficiency and many CEOs
will have asked their CIOs why the power costs have been so high, despite it
being winter and no refrigeration being needed.
In other words, energy is still being wasted on non‐optimised systems,
which are run decentraly under unfavourable preconditions.
As a general rule, it can be said that each non‐virtualised server running in
an office environment, will cost more in terms of energy bills over its service
life, than it actually cost to purchase.
Future view
The City of Vienna offers what it calls remote cooling via the Vienna utility
company (Wiener Stadtwerke). The heat created from incinerating waste is
converted to refrigeration energy in absorber refrigeration plants and
supplied to customers much like district heating. This technology offers the
benefit of being more efficient than conventional, electrically operated
compressors.
New high‐temperature cooling systems
By increasing the cooling water temperature from around 10–15°C prefeed
temperature to around 50°C, re‐circulating air can be used for cooling most
of the year; companies can do without energy‐gobbling refrigeration
systems, as the example in Ireland shows. The precondition for this is that
cooling occurs directly at the system's high temperature area, for example,
cooling the CPU directly with water. Under load, modern CPUs can reach a
temperature of up to 90°C; this means that datacentres can use a high
temperature water circuit that is either cooled down to an ambient
temperature by recirculating air radiators, or preferably, the hot water is
used elsewhere for heating rooms or preparing hot water.
Another effect of this approach is to transfer heat directly to the medium
water, instead of ambient air; the efficiency of the heat transition is
increased 20‐fold. IBM already has a system of this type in operation.
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