Now, thanks to a cooperation between Danfoss and Sønderborg District Heating, the Danish supermarket chain SuperBrugsen in Høruphav on the island of Als, Denmark, is also a district heating supplier. Residents living near SuperBrugsen have their district heating supplied from the recovered surplus heat from the cooling system in SuperBrugsen, and thereby help contribute to reducing CO2 emissions.
Around 20 Danish supermarkets send surplus heat to the district heating networks – now also in Høruphav, a small town in Southern Denmark. With this investment, the Danish supermarket chain, SuperBrugsen, will make a difference for the environment, because heat recovery reduces the impact of CO2 emissions on the environment.
“Currently, we see the potential of refrigeration systems in not only Denmark, but worldwide, to become an integrated part of the distributed district heating network. This means that supermarkets or butcheries with large refrigeration systems, or in principle all undertakings with large refrigeration systems, may shift from being consumers of energy to also become suppliers of energy. Until only a few years ago, the big news was that you could utilise the heat in refrigeration systems to heat supermarkets. Today, this technology is applied in most new supermarkets, but now, the very same supermarkets can also supply heat to private homes, which are located nearby,” says Danfoss engineer Torben Green, who is part of the project team behind the development of the solution in Høruphav.
“It is slightly more expensive installing the solution in old stores, but all new supermarkets should reuse the surplus heat from the refrigeration system as district heating. It is much cheaper to set up the solution when you begin to build a new store,” says Torben Green.
Significant environmental savings
SuperBrugsen in Høruphav already saves more than DKK 200,000 annually on gas and reduces CO2 emissions by 34% by utilising the surplus heat from the refrigeration system to heat tap water for cleaning, among other things, and with the new district heating connection, SuperBrugsen has one more source of income, namely by selling district heating to the Sønderborg District Heating consumers.
“SuperBrugsen now has an environmentally-friendly solution, which matches their green profile very well, with heat recovery and solar cells on the roof, and on top of this, the investment is paid for within 12 months only,” says Torben Green.
Supplying 16 private homes
The fact that Sønderborg District Heating is now receiving surplus heat from SuperBrugsen in Høruphav is fully in line with its vision to distribute and supply environmentally-friendly district heating.
“Calculations show that the surplus heat from SuperBrugsen will supply 16 so-called standard homes of 130m² annually. The project has been smooth, and has been run in close cooperation with Danfoss and SuperBrugsen,” says department head Jan Due Kristensen, Sønderborg District Heating.
“This is a great example of how to incorporate district heating as a two-way energy infrastructure to distribute and thereby utilise energy, which would otherwise have been lost. Based on the political objectives of phasing out fossil fuels and utilising renewable energy and surplus energy sources to a greater extent, district heating will play a key role for the urban energy systems of the future,” says head of development Jan Eric Thorsen, Danfoss Heating.
How does it work?
In principle, all supermarkets – like SuperBrugsen in Høruphav – which are located near a district heating supplier can supply heat from the refrigeration system to nearby residents. The largest cost incurred by the setting up of a district heating network is the digging for the district heating pipes and the purchase of a pump. The refrigeration system takes care of the rest.