In Sønderborg, we are not only aiming for a carbon neutral energy system in 2029. We want an accelerated and cost-effective decarbonization, and the backbone is a 3 step recipe with a strong focus on energy efficiency. Since 2007, we have worked systematically with decarbonizationing the energy system of an entire municipality, so our recipe has been tested, tried and has proven its’ value. Also, when we unlock the full potential for energy efficiency, we unlock the full potential of renewables. 




Without urgent action, energy demand will grow significantly, getting us off track to meet global climate goals. Instead, according to IEA a collective push for energy efficiency can deliver one-third of the total emissions reductions needed to reach net zero.

In Sønderborg, we have taken early action on energy efficiency. The effect is clear:

  • In the period 2007-2020, energy efficiency has reduced the need for expansion of renewable energy corresponding to 130 kton CO2
  • Energy efficiency contributes 27% of the total CO2 reduction in the period 2007-2029
  • The accumulated CO2 emission over the entire period has been reduced by 8 mton
  • Cheap reduction costs of DKK 170/ton (vs. DKK 390/ton without EE measures)
  • Without EE initiatives, CO2 emissions would have increased from 701 to 760 kton due to growth in society

Our three step recipe on cost-effective green transition


Energy efficiency is maybe the most important key word in Sønderborg’s recipe for cost-effective decarbonization. When we use less energy to perform the same task, we eliminate energy waste. Today energy is being wasted everywhere across sectors. In the industrial sector, inefficient electric motors waste energy and the excess heat that is generated from production is not utilized. And in buildings vast amounts of energy is wasted because simple measures to monitor and control energy use are not in place.

Electrifying is also a way of saving energy because electricity in general waste far less energy than fossil fuels. In gasoline powered vehicles for instance around 80 percent of the energy is lost. Electric vehicles on the other hand uses 80 percent – wasting only 20.

The growing demand for green energy makes our focus on energy efficiency even more urgent. Reducing our energy waste makes it more likely that we can cover our energy need with energy based on renewables.

Reuse og integrate

Since green energy is a scarce resource, we must use it wisely, so that it puts as little strain on the energy system as possible. It increases the energy efficiency of the energy system and provides the cheapest and greenest energy consumption.

Sector integration is the final main lever in decarbonizing our energy system because it makes it possible to reuse the rejected and otherwise wasted energy.

It might sound a bit technical. But more importantly, sector integration is about people and partnerships – working together and maximizing synergies between sectors, connecting energy consumers with energy producers, and converting and storing energy.

The Sønderborg area is collaboratively developing an integrated energy system across various sectors. This enables us to optimize the utilization of excess heat by incorporating it into our district heating network. The anticipated outcome is that by 2029, up to 40 percent of our district heating will be sourced from surplus heat.

Sector integration has 3 development phases which complement each other and gradually create better opportunities for green energy consumption in society: Reuse excess heat, electrification, and Power-to-X on renewable energy.

One of the key challenges in decarbonizing our grid and increasing electrification is ensuring that supply matches demand. By looking at the energy system holistically and linking different energy sources, sector integration allows for flexible use of power. It enables discrepancies in supply and demand to be evened out so we can exploit the full capacity of the grid. Balancing the peaks will be particularly important as we increase the use of renewables and electrification takes pace.

Digitalization is the intelligent glue that moves renewable energy, streamline, and reduces energy consumption across sectors – making the decarbonization cheaper.


No matter how effective our efforts are in conserving and reusing energy, we will always have a substantial energy requirement. Therefore, it is essential, that we ensure our future energy needs are completely met with clean energy sourced from wind turbines, solar farms and biogas production. And green district heating instead of fossil fuels for heating.

The most effective way to secure a 100 percent green energy supply is by actively producing as much of it as we can. This is why we presently operate two biogas facilities in the towns of Kværs and Glansager. Furthermore, there are ambitious plans for an offshore wind farm in the Little Belt east of Als, in addition to expanding wind turbine and solar panel installations on land.

Efficient and sustainable PtX production is essential for a deep decarbonization. A PtX plant can convert and store excess renewable energy as hydrogen. And while this conversion comes with an energy loss, hydrogen will be key to decarbonizing hard-to abate sectors such as heavy industry production, long-distance shipping, and long-haul aviation.

Since hydrogen production will have a massive pull on the electricity grid in the future, it is of great importance to use it wisely for the right purposes. Hydrogen production must be based on additional locally produced renewable power to be sustainable, and we must ensure that the production is as efficiently as possible by reusing excess heat in district heating and not create unnecessary disturbances on the grid.


Case Sønderborg

We strengthen the competitiveness, reputation and innovative power of our companies

Energy efficiency makes a society based on renewable energy possible