In 2024, Sønderborg reached an important milestone on the road to making the entire region’s energy system CO₂-neutral by 2029, having reduced three-quarters of the 700,000 tons of CO₂ we emitted in 2007.
See our Energy and CO2 Report for 2024.
Back in 2007, when the Sønderborg area made a shared commitment to help reduce global CO₂ emissions by making the region’s entire energy consumption carbon neutral by 2029, few Danish municipalities had any concrete climate plans. Today, every municipality does.
But it’s not simply what we’re doing that draws people from around the world to Sønderborg for inspiration on green transition.
It’s how we’re doing it.
Our approach follows three straightforward steps. And it’s not only environmentally friendly – it’s also cost-effective. Thanks to our early focus on energy efficiency, we’re able to drive the green transition at roughly half the cost it would have been otherwise.
Three steps to a green transition
Reduce energy
We reduce energy demand by saving energy and electrifying cars, heating systems, and other fossil fuel–powered uses. After all, the greenest – and cheapest – energy is the energy you don’t use.
Reuse energy
At the same time, we are building an integrated energy system that, among other things, recycles energy that has already been produced. The goal is for 40 % of district heating to come from surplus heat by 2029. Additionally, sector coupling focuses on improving efficiency by making the best possible use of energy flows across different sectors. For example, capturing CO₂ from the burning of straw and wood chips and combining it with hydrogen to produce green fuels.
Renewables
The electricity we use must be green and come from renewable energy sources.
Meet some of our climate-conscious residents and businesses
The energy system is key to our plan
We won’t reach zero emissions by chance, but through a focused and dedicated effort where we can see and measure the results. We call this Masterplan2029. It’s also how we manage to maintain momentum on such a large and ambitious project spanning 22 years.
The backbone of our plan is an integrated energy system that uses energy as efficiently as possible. This ensures we don’t produce more electricity than necessary. Electrification requires enormous amounts of power, and only by making the different parts of the system work together properly can we optimally balance production and consumption—thereby minimizing the area’s total energy costs. For example, we utilize surplus heat from the upcoming wastewater treatment plant to provide district heating for homes. The same applies to electricity, where we ensure power is used for the right purposes at the right times. This way, we avoid investing more than necessary in production and infrastructure, helping to keep electricity prices down.
The Sønderborg area won’t be completely CO₂-free by 2029, but the municipality will be CO₂-neutral because we will capture CO₂ and produce more biogas than we consume ourselves. This contributes to making the national energy system CO₂-neutral, and the surplus energy will have a positive impact on the climate balance.
The elements of our energy system
District heating
The district heating supply in the Sønderborg area is provided by two separate utilities. Both providers are working to phase out the last use of fossil fuels and make their district heating fully CO₂-neutral. District heating allows the use of multiple energy sources, including surplus heat from local companies.
Biogas plants
Biogas is an important energy source for parts of the industry that require high temperatures in their production. In the Sønderborg area, we have three biogas plants connected to the gas grid – two in Kværs and one in Glansager. The biogas plant in Glansager also hosts the world’s first Power-to-Gas facility.
Offshore wind farm
The upcoming offshore wind farm, Lillebælt Syd, will supply green electricity to citizens, institutions, and businesses in the Sønderborg area. The wind farm is expected to be operational by 2029 and produce 165 MW of green electricity – equivalent to the electricity consumption of 148,000 households.
Onshore renewable energy
Fourteen areas have been designated as potential sites for new solar and wind farms. This is part of the Danish government’s plan to quadruple onshore renewables and ensure all electricity is green by 2029.
Carbon Capture
Opportunities for CO₂ capture from sources such as flue gas in energy production are being explored in Sønderborg. The captured CO₂ can either be stored underground (CCS) or used as a resource in solutions such as Power-to-X (CCU).
Wastewater treatment plant
Wastewater from a new treatment plant will play an important role in our energy supply. It is possible to extract heat from the wastewater and transfer it to the district heating network. The treated wastewater can contribute to sector coupling in the area.