Circular energy in practice

One company's residual heat is the other's source of energy: Circular energy in practice

For the first time in GreenLab, it is now possible for two companies to share their excess energy. The sharing will begin when a heat connection between Stiesdal's SkyClean plant and GreenLab Skive Biogas is opened. In the new pipes, surplus heat from Stiesdal's pyrolysis production is directed to the biogas plant, which consequently can replace approximately 20% of its natural gas consumption with green energy that would otherwise have been wasted. The connection is the first stage in GreenLab's unique SymbiosisNet.

The idea of circular energy now goes from theory to practice in GreenLab's green industrial park. Here, two of the park's companies can reap a concrete benefit from the park's so-called SymbiosisNet – an intelligent network of energy that allows companies in the green industrial park to share their excess energy with each other. 

Today, a newly installed heat connection between Stiesdal's SkyClean plant and GreenLab Skive Biogas is opened. The connection will transport excess heat from Stiesdal's pyrolysis plant to the biogas plant that can use the heat in its upgrading facility where biogas is cleansed of CO2. With the excess heat from Stiesdal, the biogas plant can replace approximately 20% of its current heat consumption. Stiesdal, on the other hand, can utilize the heat that would otherwise be wasted and can convert the heat into a saleable product for its neighbour. 

Utilising waste is good business

The heat from Stiesdal is a 140°C hot energy source of 1.2MW. In total, the biogas plant needs 5MW, and the heating pipes are dimensioned so they can cover the entire energy requirement in the future – for example via residual heat from other companies in the industrial park or excess heat from GreenLab's two upcoming Power-to-X facilities. 

"It's a good solution for both us and the green transition", says Christian Frandsen, Director of GreenLab Skive Biogas. "We buy a surplus product from our neighbour, and we can use it in our production. We look forward to exchanging even more energy and heat with companies in the industrial park in the future". 

The symbiosis also makes sense for Stiesdal. Peder Riis Nickelsen, Managing Director of Stiesdal SkyClean, says: "SkyClean is built on the idea of utilizing residual biomass for both CO2 capture and storage and for the production of green energy, so the possibility of using our excess heat from the pyrolysis plant in a sensible way fits perfectly into our way of thinking. And it's also good business – our surplus heat comes from pyrolysis gas, and with this solution, we turn the gas into a product we can sell. It's a win-win situation". 

Flexible solution with supply security 

GreenLab Skive Biogas operates 24 hours a day, while Stiesdal, for now, only produces periodically. But the biogas plant does not have to worry about getting enough heat from Stiesdal. The system is set up so the heat from Stiesdal is automatically used in the biogas plant when it’s available – and when it’s not, the biogas plant simply runs on natural gas, as it does today.

Factory with crane 


The heat exchange between Stiesdal's SkyClean plant and GreenLab Skive Biogas A/S is thus the first connection in the shared resource network – the so-called SymbiosisNet – which is expected to reduce the park's total CO2-emissions and increase efficiency and energy utilization among the park's factories. 

Christopher Sorensen, CEO of GreenLab, says: "GreenLab's SymbiosisNet is green conversion in practice and it’s one of the unique advantages of placing a green business here with us. We are very happy that Stiesdal and GreenLab Skive Biogas can now demonstrate what a circular economy can look like in reality and show how to transform a waste product into a valuable resource". 

For further information, please contact:

GreenLab: Linda Fejerskov, Communications Consultant, GreenLab. Mail:, phone: 29 81 17 22 

Stiesdal: Kristian Strøbech, Head of Communications, Stiesdal. Mail:, phone: +45 20460440 

GreenLab Skive Biogas: Christian Koustrup Frandsen, Director, GreenLab Skive Biogas. Mail:, phone: 30386120