Articles

Kalundborg, a hub of industrial innovation in Denmark, is taking a bold step toward sustainability and efficiency with the construction of a state-of-the-art district cooling and heating plant. This ambitious project, set to transform the way cooling and heating are delivered to industrial giants like Novo Nordisk and Novozymes, is planned for completion in early 2026.

By William Ejsing, Press Officer, Kalundborg Forsyning

Published in Hot Cool, edition no. 8/2024 | ISSN 0904 9681 |

With a price tag of 1.4 billion DKK (nearly 190 million EUR) and a capacity to deliver up to 166 MW of cooling, this facility promises more than just cutting-edge technology—it represents a leap forward in reducing environmental impact and resource waste. By tapping into Kalundborg’s unique coastal resources and leveraging advanced engineering, the plant aims to replace conventional systems with a solution that eliminates chemicals, minimizes energy waste, and recycles heat for broader use.
This transformative project underscores Kalundborg’s reputation as a pioneer in eco-industrial symbiosis, where collaboration, sustainability, and innovation converge to meet modern industrial needs.

Cooling: Essential for Major Productions in Kalundborg

The expanding production needs in Kalundborg require greater cooling capacity, and district cooling has been chosen as the solution.
Hans-Martin Friis Møller, CEO of Kalundborg Forsyning, stated:
“Providing district cooling to the local industry is a natural step for us as a long-established supplier of critical resources like water, energy, and wastewater management. At Kalundborg Forsyning, we have a longstanding tradition of delivering circular and sustainable utility solutions in collaboration with our local partners. The district cooling system, which we believe will be the largest industrial district cooling facility in Europe, is a prime example of this.”
The plant will replace the cooling towers and systems currently in use, offering a solution free from chemical usage while reducing waste of energy, water, and materials.

The Technology Behind the Plant

The plant will draw 18,000 m³ of seawater per hour at maximum capacity from an intake point in Kalundborg harbor. On average, only half this amount is expected to meet the cooling demands. The underwater intake is designed to allow water to flow in smoothly without causing significant surface currents.

Filtration and Pumping

Seawater will undergo a two-step filtration process underground. Special pumps, made from corrosion-resistant super-duplex materials, will push the seawater to the heat exchanger station.
The industrial cooling circuit operates as follows:

• Warm water returning from industrial processes is cooled using the lower temperature of the seawater in titanium heat exchangers, which resist corrosion.
• The cooled water, with a maximum temperature of 22.5°C (preferably lower during cooler periods), is then circulated back to the industry.

The closed-loop system connects Kalundborg Forsyning with Novo Nordisk and Novozymes via an underground pipeline nearly one kilometer long. This pipeline, two meters in diameter, includes both forward and return water circuits.

Temperature Management and Additional Cooling

When water returns from the industry, its temperature may reach up to 31.5°C. During summer, higher seawater temperatures could prevent achieving the target cooling temperature of 22.5°C. To address this, the plant is equipped with 10-MW chillers that provide supplementary cooling during peak periods.
After its use, the warmed seawater is discharged into the harbor at a separate location to avoid interference with the intake.

Harnessing Waste Heat for District Heating

The project also explores utilizing waste heat from the district cooling plant for district heating. Hans-Martin Friis Møller emphasized:
“A logical next step is investigating how we can use surplus heat from the new district cooling plant to produce district heating.”
By boosting the temperature of the return water with additional industrial waste heat in Kalundborg, it could reach approximately 80°C—the standard temperature for district heating water.
Estimates suggest that this method could generate district heating for 40,000 households, using surplus heat efficiently and sustainably.

For further information please contact: William Ejsing, wile@kalfor.dk