HOFOR's first district cooling centre was ready in 2010 in the
old factory buildings Turbinehaller on Adelgade in the heart of
Copenhagen, and yet another centre was ready at Tietgensgade near
the City Hall Square in 2013.
The Tietgensgade centre from the outside.
These plants can produce cooling centrally in three different
ways:
Seawater. In the winter months, cooling is
solely produced by means of seawater which is led into the cooling
centre through a pipe between the harbour and the centre. This type
of production is completely carbon-free and is called 'free
cooling'. However, a small volume of electricity is used when the
cold water is pumped out to customers. The rest of the year,
seawater is used to enhance the efficiency of other installations,
as the seawater is used to cool for example cooling
compressors.
Steam. In summer months, steam is bought from
CHP production, as heating consumption in the summer is very low.
Here, waste incineration represents a large part of the steam
production, and therefore carbon emissions are low for cooling
production based on steam in the summer. This method is called
absorption cooling.
Electricity. Electricity compressors are used
in the summer months; seawater is used to remove surplus heat from
the compressor machines. A number of different capacity electricity
compressors are available on the market. This mean there is always
a machine which fits the cooling consumption. Thus, efficiency is
significantly increased for electricity compressors compared with
the compressors which buildings might alternatively have installed
to cover their cooling needs.
In future, district cooling centres will be expanded in the rest
of the capital. At the moment, HOFOR is assessing possibilities in
seven other areas in Copenhagen. The plan is to establish district
cooling in Nordhavn, Kalvebod Brygge, Islands Brygge and Sydhavn,
among other places.