Customer case - Sønderborg Varme


We advise Sønderborg Varme in their strategy to offer green district heating to the areas to replace fossil heat. In addition, we calculate and assess the potential of geothermal energy and the use of excess heat from local wastewater plants and brickworks.

Project and Development Manager Tue Gejl Christensen:

Here, Tue Gejl Christensen, Sønderborg Varme's Project and Development Manager, explains their strategy and our consultancy services:


(Click the picture of Tue)

Sønderborg Varme is engaged in many projects to ensure the green transition. These include the possibility of applying various heat generation technologies and the coupling of local district heating areas.

Converting to green district heating is no mean feat. But ensuring cheap and robust supply at the same time is a great achievement.

This is exactly what we help design by drawing up a coherent plan - what we call a roadmap.

The roadmap describes the pace and tone of how to implement the new heat sources. The roadmap covers the phasing out of existing plants and ensures robustness against future changes in market conditions.

Source: Sønderborg Varme

The figure above shows the new transmission line between Dybbøl and Adsbøl, as well as the towns of Nybøl and Vester Sottrup, which are gas areas. The project proposal prepared by Added Values suggest connecting Nybøl and Vester Sottrup to the district heating network, and establishing the transmission line between Dybbøl and Adsbøl and a biomass boiler in Gråsten. The transmission line thus connects Sønderborg and Gråsten.

Next step is how to connect Avnbøl, Ullerup and Blans to the district heating network. Danish Crown is located between Ullerup and Blans and is potentially a large heating customer.

Avnbøl and Ullerup will be connected to the district heating network regardless of whether the abattoir is connected or not, whereas Blans is only connected if an agreement between Sønderborg Varme and Danish Crown is reached.

AVPLAN model

Based on the AVPLAN calculations, the customers are able to decide which energy solutions to invest in – where and when.

The below figure illustrates Sønderborg Varme. The AVPLAN shows existing plant, suggests new plant investments and their location.


A dotted line around a plant means suggested plant investment.


(Waiting for English version)

 Our AVPLAN software is based on the modelling language GAMS, and we have continuously developed the softtware for almost 10 years. And we keep on developing it.

You find more information on how we use AVPLAN to design district heating systems in this article

August 2023