16
OPINION
wide range of free cooling techniques can be implemented.
The most commonly used practice around the world is to
combine a free cooling solution with DX cooling that can
take over on hotter days.
In the Nordics however, with hotter days relatively rare,
some operators simply choose to allow temperatures to rise
above the standard for a few hours per year. This is instead
of investing in full-sized redundant compressor cooling – an
expensive purchase, which will barely be used but will still
require maintenance.
The Nordic climate not only delivers significant CAPEX
and OPEX benefits when it comes to cooling a facility
though. The colder outdoor temperatures mean that there is
an opportunity to recycle the waste heat that a data centre
generates, by pumping it in to the district heating networks
in place in most Scandinavian and Baltic cities. According to
Invest in Finland, selling excess heat from a data centre can
make it 40–50% cheaper to run that facility in the North
rather than in Central Europe. So not only is money saved,
but also the environment with the carbon footprint reduced
even further.
Of course, depending on business priorities and the
design of the planned facility, different site types might be
appropriate. For example, hyperscale deployments requiring
tens of megawatts of power tend to be located in more
remote areas, close to the renewable power generation
sources they need.
On the other hand, colocation companies with medium
power requirements (0.5MW to 5MW) tend to cluster around
cities where they can be closer to potential clients, more
easily accessed by their workforces and exploit an additional
revenue source from selling excess heat to the local heating
networks. And in efficient Nordic fashion, prepared sites are
available in every type of location.
Reducing costs and carbon
Well developed electricity grids and the abundance of
generated power often allows data centres in the Nordics
to simultaneously connect to two separate utility feeds,
thus providing redundancy without needing to resort to
diesel generators. As a result, many facilities only have
one generator on site for back up while others opt out of
generators entirely, completely relying on their two grid
power supplies.
Of course, relying entirely on third-party utility companies
should be carefully evaluated before a final decision is
made. However, to put the risk in to perspective, Boden – a
municipality in the north of Sweden – had its last power
outage almost 40 years ago. And with the cost of electricity
in Sweden the lowest across all of Europe, there’s a
compelling argument to be made.
Data centre cooling is another area where the Nordics
offer an attractive solution. Facilities can be cooled with
cold outside air or water throughout most of the year, and a
Build smart to reduce costs
Start small, build fast, expand as you grow – this is an ideal
way to build a profitable data centre. But is this actually
attainable? With the right approach it is, and the answer is
prefabrication.
Emerging markets were quick to adopt prefabrication as
a new way to build data centres. This was due to a number
of factors such as initial CAPEX constraints, concern over the
speed of new service uptake or a lack of local materials and
expertise to actually build a facility. Meanwhile, data centre
operators in developed markets have typically continued
to build in a traditional linear process: ground works,
constructing a traditional brick and mortar building on site,
equipping it with the necessary data centre subsystems,
testing and finally commissioning it.
That, however, is starting to change with the realisation
that (unlike containerised solutions with which they are
sometimes confused) prefabricated buildings have no
limitations on their critical infrastructure design and can
satisfy the requirements of most Nordic colocation players.
In fact, the advantages of prefabrication are already widely
recognised in the Nordic region. For example, in Sweden
more than 80% of detached houses are prefabricated. This
is in part due to the fact that the further north you travel,
the shorter the building season is, so constructing, outfitting
and testing the majority of a data centre (or house) in
a clean factory environment helps ensure that the time
required for final construction and commissioning on-site is
kept to an absolute minimum – a crucial requirement when
faced with the onset of a dark and inhospitable winter.
When it comes to data centres, where the facility itself
is part of a complex machine rather than simply a weather
shell, the advantages of prefabrication extend far beyond
the speed of delivery. Here, prefabrication’s benefits include
increased cost-efficiency, predictability and flexibility. n
www.networkseuropemagazine.com