District cooling holds great potential for utilization of excess heat from Kalundborg Symbiosis

Surplus heat from cooling industrial production in Kalundborg can be converted into sustainable district heating in the future. Enough surplus heat from industry is generated to potentially heat more than 40,000 households. Today's announcement by Kalundborg Utility, Novo Nordisk and Novozymes of an investment of €1.4 billion in Kalundborg's energy sector is a major step forward. DKK in a new district cooling system in Kalundborg, puts the pressure on to make the ambition a reality. It will allow surplus heat to be collected and used to heat households. With the right infrastructure in place, the new district cooling system alone will generate enough surplus heat to potentially replace natural gas in Holbæk and heat the city of Kalundborg. Kalundborg Symbiosis has therefore initiated a project to use surplus heat from production to heat households in North West Zealand. In order for the heat to reach the households that need it, the supply network in the Kalundborg area must be connected to a larger district heating network.  

Sustainable district heating for Denmark's largest natural gas city Holbæk Municipality, Denmark's largest natural gas city, is invited to join the cooperation. The parties are now planning to jointly link industry's need for cooling and the resulting surplus heat with the need for sustainable district heating. The coupling will take place across public and private partners and will create a robust and sustainable solution that reduces the consumption of fossil energy for heating. Finally, the project has the advantage that it can be built in stages and expanded in a modular way as opportunities arise and/or demand increases. 

Denmark's largest sector coupling project "Our shared ambition to harness surplus heat from industry creates potential for green transformation, increased security of supply and resource optimisation across sectors, municipalities and industries. That is why Kalundborg Symbiosis is working very hard to realise the project as soon as possible. It is a very dedicated circle of public and private parties that are behind it", says chairman of Kalundborg Symbiosis Michael Hallgren, who is also production manager at Novo Nordisk in Kalundborg. "Together we can create a model for sector coupling that promotes green transition and independence from natural gas. And at the same time put Denmark on the map as a home for urban-industrial symbiosis," Michael Hallgren concludes: "The project will be the largest sector coupling project in Denmark".

Significant environmental effects Jesper Haugaard, Vice President of Kalundborg Symbiosis and Vice President in charge of Novozyme's production, welcomes the great potential: "It will have significant environmental effects to exploit the surplus heat from the industry in Kalundborg. Today, the excess heat from our production in Kalundborg is not used, as we have not had the opportunity to collect it. With the establishment of the new district cooling system, which will supply district cooling to our and Novo Nordisk's factories in Kalundborg, we will have the opportunity to collect the surplus heat. The surplus heat can then be converted into district heating via a heat pump, replacing natural gas or district heating produced from fossil sources. It is an exciting and ambitious project that fits well with our mindset in Kalundborg Symbiosis, where we use each other's waste and residual fractions as resources across the industry." Sector coupling, where surpluses from industry can be used as a resource in the local community, makes sense in a municipality where collaboration is a natural way to solve challenges.

Circular thinking the norm in Kalundborg Mayor Martin Damm, Kalundborg Municipality, says: "In Kalundborg we have 50 years of experience in thinking sustainability and circularity into our supply streams. Therefore, it is also quite natural to think of surplus heat as part of the heat supply. It is also natural to invite Holbæk to become part of the solution. On the one hand, there is a clear need in Holbæk Municipality for more sustainable heat, and on the other hand, the whole circular mindset has also become a natural part of the way we think about cooperation in Kalundborg Municipality."   

A great and long-awaited idea The neighbouring municipality of Holbæk is also enthusiastic about the project: "The ambition to use surplus heat from Kalundborg is a great idea. We have 17,500 households in Holbæk municipality that are heated with natural gas. So it is both a win for the climate, if we can get a green heating solution for Holbæk Municipality, and for those of our citizens who can eventually replace their natural gas and oil furnaces with district heating", says Christina Krzyrosiak Hansen, Mayor of Holbæk Municipality. Kalundborg Symbiose is dedicated to making the project a reality as soon as possible, not least in light of the current energy crisis. Work is also underway to involve other partners in the Symbiosis so that the cooling system can be extended to cover more production areas in Kalundborg. In this way, even more surplus heat can be collected, which can contribute to the green transition from natural gas.  

Phase 1: Decision on the establishment of district cooling for Novo Nordisk and Novozyme's joint production site in Kalundborg has been taken in October 2022, as stated in the press release of 24 October. District cooling is a prerequisite for collecting excess heat from the factories involved. Phase 2: Dialogue on expansion and involvement of more partners in Kalundborg Symbiosis ongoing. Phase 3: Cooperation between Holbæk and Kalundborg municipalities on the use of surplus heat is established.