Our recipe for costeffective decarbonization not only has the potential to solve the climate challenge in Sønderborg, but in cities worldwide.  Therefore, Sønderborg hosted the International Energy Agency’s (IEA) annual conference in 2022, where we were also named The Global Capital of Energy Efficiency. 

During the IEA conference in 2022, Sønderborg acted as host city. But more importantly, the city and surrounding areas also acted as a global showcase of energy-efficient solutions and technologies. Whereas many conferences take place in meetng rooms, the participants at the conference in Sønderborg got the chance to experience the results of  Sønderborg’s long-term and targeted efforts with decarbonizating a municiapality in action – with visits at e.g. Denmarks most energy efficient brick plant,  a carbon-neutal building site and world’s longest ranging electric ferry.

Energy efficiency plays an important role in solving the climate crisis.  The cleanest, cheapest, most reliable source of energy is what countries can avoid using, while still providing full energy services for citizens. That is why the IEA refers to energy efficiency as the “first fuel”. Without early action on efficiency the energy transition to net zero emissions will be more expensive and much more difficult to achieve.

The IEA’s own findings have concluded that energy efficiency can deliver a third of the reductions needed to reach the Paris Agreement’s climate goals

Sønderborg's recipe for a green turnaround


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.


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.

Sønderborg Action Plan

A reminder of the central role that energy efficiency can play in alleviating today’s energy challenges and providing a useful blueprint for governments to turn ambition into action. That is the ambition of Sønderborg Action Plan, which was one of the most important outcome of the 7th IEA Annual Global Conference held in Sønderborg in 2022. The plan is a set of strategic principles and policy toolkits developed by the IEA that can help governments seeking to implement efficiency policies rapidly. 

Since 2022, there has been several examples, that Sønderborg Action Plan is being taken seriously – also outside Europe’s borders. India had cooling on the agenda of its G20 presidency in 2023. Refrigeration will drive the second largest increase in electricity demand in the coming decades, so it is imperative to address it.  And at the COP28 climate summit in the United Arab Emirates in December 2023, there was a focus on innovative solutions that can make cooling more energy efficient.

Read the Sønderborg Action Plan 2022

At every conference since 2022, new toolkits building on Sønderborg Action Plan have been launched.

Read from Sønderborg to Versailles, 2023
Read from Versailles to Kenya, 2024

IEA 2023


Prior to the IEA Conference in 2023, the President and CEO of the Sønderborgbased multinational energy company Danfoss, Kim Fausing, and the Danish Minister for Development Cooperation and Global Climate Policy, Dan Jørgensen stressed the need to update the thinking and policies to reflect the role of energy efficiency in a future energy system based on renewables.

“Energy efficiency is so much more than reducing demand, and it will become even more important as the clean energy transition accelerates. It is using digital solutions such as IoT and AI to create the flexibility that our energy systems will need as the share of renewables grow. It is using electrification and sector integration to use our energy smarter, matching supply and demand. We know that excess heat – from supermarkets, data centres, industry, wastewater treatment plants – in the EU corresponds to the total energy demand for hot water in residential and service sector buildings,” they stated in an opinion in Euractiv – an independent pan-European media network. 


Fatih Birol, Director of the International Energy Agency (IEA)