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SmartEnCity Site Sonderborg

Country & City

  • Denmark
  • Sonderborg


Contact Information

Sonderborg is a Danish municipality with 76 000 citizens committed to becoming a zero-carbon community by 2029, an objective pledged in the ProjectZero visionary project with a focus on sustainable growth and creating new green jobs. Energy efficiency and energy from the area’s own renewable sources are the key means to turn the vision into reality. New thinking is essential and public policy and investments fuel this transition.

The activities of the SmartEnCity project are an important contribution to reaching Sonderborg’s goal of CO2 neutrality. Based on a baseline assessment of the current situation and an active involvement of citizens in all interventions, the project will implement renovations of multi-storey buildings, planning of coastal wind farms, heat pumps, electric cars and intelligent charging stations for electric cars.

* Detailed information regarding the technical and financial performance will be available at a later stage.

With the SmartEnCity project, Sonderborg seeks to:

  • demonstrate ambitious electrification of Sonderborg’s Roadmap 2020, through rooftop photovoltaic power production;
  • green mobility solutions including biomethane buses and EV charging infrastructure;
  • retrofitting existing buildings of three housing associations in close cooperation with tenants;
  • engage the citizens as co-designers of the Smart Zero Carbon Sonderborg’s ambition to implement integrated solutions with comprehensive learning and introduce new ICT-based energy information.

Best Practices

Best Practices



So as to engage the tenants, the housing associations controlled the flow of information. The Danish housing associations are all set up similarly with residents/tenants from each department unit creating a board of residents that make decisions. Each department unit is typically made up of a few apartment buildings located next to one another on the same street. Decisions affecting the department unit in question must be brought to the board of residents which has to approve the decision and its consequences, unless it concerns safety or security; in that situation the national board of the housing association can overrule the board of residents’ decision. In this case, the resident boards voted on whether to go forward with the retrofitting measures, whether to mount photovoltaics on top of the roof or have them integrated in the roofs, etc.

The residents were also engaged through the opportunity to voluntary track their consumption of water, electricity and heat. A website was created especially for this and the residents could enter their consumption data into the website and see daily/weekly/monthly trends for their own apartment. This engagement activity was combined with educational workshops on the financial and environmental benefits of the project. Most people can relate to monetary savings, but this is difficult to use in this situation in Denmark. For example, even if a resident replaces all the lights with LEDs, the majority of the bill will stay the same due to various fees, e.g. transport fees, national fees, etc.





The project has a stakeholder engagement plan that includes how to and when to communicate what to whom. There is no matrix showing the importance/level of influence of each stakeholder, which is something that should be done for future projects. The project team tried to limit the number of people contacting each stakeholder so that time wouldn’t need to be spent bringing SmartEnCity partners up to date on every occasion when they communicated with each other. However, this became more of a burden because the person contacting the municipality for smart mobility was unable to answer any ICT-related questions.

In general terms, stakeholders included Sonderborg project partners, local authorities, residents in affected housing associations, citizens in general, current and potential future e-vehicle owners, local businesses, SmartEnCity project partners and the project officer. Communication was done through various channels, but all stakeholders were met in person for the first few times to create a personal link and eradicate any misunderstandings. Email was used for complicated or extensive questions, and phone calls for quick and short questions and clarification. Furthermore the website was set up for the local stakeholders to be able to find information in Danish about the initiatives in their immediate surroundings.


A barrier to the smart mobility actions was the Danish tax system, which dictates that ‘gifts free of charge’ must be taxed by the receiver for the value of the gift. Therefore it was difficult to give away intelligent electric vehicle chargers, as had been the original plan. Private owners especially did not see the benefit of having to pay taxes for the combined value of the charger and the costs associated with installing the charger.

As a compromise, local businesses and car dealerships were targeted rather than private households. This, however, posed different challenges, because the intelligent e-vehicle chargers typically have the greatest benefit if left to charge overnight; however, vehicles parked at local businesses typically belong to employees or visitors and will not be parked overnight. The project team is treating this as an interesting case study to identify how the intelligent chargers perform in this setting.


A national regulatory change announced in 2016 forced the cancellation of the programme where electricity from photovoltaics sold to the grid received a guaranteed price per kWh rather than the fluctuating spot market price. Options that may become more popular in the future are with the energy service companies (ESCOs) that take over the investments related to energy efficiency intervention. In exchange, they receive monthly payments from the energy cost savings., guaranteed  for a set period of time.


In 2016, it was announced that the financial incentive for open-door wind turbines will end in 2018. Only the wind turbines connected to the national grid by 21 February 2018 are entitled to receive the incentive. This made the business case for many early-stage projects worse and endangers their entire feasibility. The change is especially burdensome due to the short time frame in which it is impossible to speed up wind projects to gain access to the incentive. Future public subsidies should not be taken for granted, and the planning stage of project replication should include a Plan B for a changing regulatory environment.


* Detailed information regarding the technical and financial performance will be available at a later stage.

The solutions demonstrated in Sonderborg include:

Energy efficiency in buildings

  • Retrofitting the building envelope
    • Altogether 45 multi-storey buildings (a total of 880 apartments with approximately 66 000 m2 floor space) will be renovated

Energy systems integration

  • Photovoltaics
  • Thermal collectors
    • Solar thermal collectors will be installed on the buildings’ rooftops


Mobility & transport: 
  • Clean fuels and fueling infrastructure through soon-to-be locally produced biomethane
  • Clean vehicles
    • Smart electric vehicle-charging stations will be installed, and city bus fleets will be extended by bio methane buse
  • ICT as planning support
    • A new ICT system will be introduced, which will collect and analyse data