We have previously looked at the district heating networks in Brest and Auxerre in France, now it is time to discover the heating and cooling networks in the Finnish capital, Helsinki.

Helsinki in brief

Helsinki is the capital and largest city of Finland with 602,000 inhabitants within the city limits. It covers an area of ​​715.49 km2 – of which 70% is water and 30% is land. This is an extremely cosmopolitan city, with over 130 different nationalities present in the city.

The average temperature in winter is -5 ° C, while in summer, the daily temperature ranges between 14 and 18 ° C. The highest recorded temperature in Helsinki was 31.6 ° C on July 18, 1945 and the lowest recorded temperature was-34.3 ° C on January 10, 1987.

Trigeneration for “Helen”

District heating and cooling networks in Helsinki are managed by the company Helsingin Energia – or “Helen” as it is better known. The system works on the principle of trigeneration in order to produce electricity, heat and cool air.

To accomplish this, different resources and technologies are used:

• For electricity production: 50% is produced by nuclear energy, 33% from fossil fuels and 17% via renewable resources.
• For heat: Russian natural gas is responsible for 48%, coal 45%, heat pumps 5% and oil 2%.
• For the production of cold air: heat pumps accounts for 59%, absorption chillers 24% and water from the sea 17%.

Four major plants

The network built by Helen relies on many installations. These installations include:

• 4 cogeneration plants;
• 13 hot and cold air generation plants;
• 5 storage facilities;
• 1 autonomous heat pump producing hot and cold air.

It should be noted that the heat generated by data centres is also recovered. This energy, which had heretofore been lost, now supplies district heating and cooling networks!

The Helsinki cooling network system utilises the heat lost in energy production units in cogeneration. To do this, Helen uses absorption refrigerators, which exploit the natural freshness of the sea water in winter. The goal? A 90% reduction in power consumption used to cool the city of Helsinki.

2 in 3 inhabitants connected

The heating network system in the Finnish capital is undoubtedly a great success for Helen. It provides heating for more than 400 000 inhabitants of Helsinki, at a capacity of 3300 MW. This represents more than 2 people in 3! As for the cooling network, it is connected to over 250 buildings, with a capacity of 135 MW. These steadily increasing numbers are pushing the country to consider creating general heating and cooling networks in the future. And an added advantage of this general network is that it will help reduce the emissions of greenhouse gas relative to personal facilities by 80%!

Technically impressive, energy efficient and environmentally responsible, the district heating and cooling network of Helsinki is a global benchmark. It proves, if more proof was necessary, that the northern European countries are leading the way in terms of sustainable development!

Image source: Flickr (Noria)