How can you conceal a 52-hectare high-voltage substation?

Before starting to design a new substation for Energy Island Bornholm, we consulted the islanders for their advice instead of inviting leading international architects to compete for the task. The exercise spawned lots of good ideas, and resulted in a substation that challenges the conventional approach and which hopefully gives something back to the area.

How do you place a 52-hectare high-voltage substation so that it inconveniences as few people as possible? In fact, is it even possible to get 25-metre high buildings to blend into the undulating landscape on southern Bornholm? And how do you involve the locals in resolving these questions, when they would rather not have a substation in their back yard in the first place?

These were some of the issues that Energinet faced in autumn 2022, when the Danish state’s TSO had to start planning the future substation. The substation will be at the heart of Energy Island Bornholm, and will collect and send green electricity to more than 3 million households on Zealand and in Germany.

“Normally, design work and integration with the surroundings is something we do together with our consultants, after which we ask the municipality to prepare a district plan. However, with a substation of this size – 52 hectares of technical plant – it soon became clear that it was a much more challenging exercise than usual. At the same time, the Regional Municipality of Bornholm and the Municipal Council wanted us to take greater pains with the architecture. And perhaps even hold an architectural competition. The substation will be one of the largest buildings on the island, so the idea of simply concealing it was not realistic either. Therefore, we had to find a way of creating something that would hopefully add long-term value for Bornholm,” says Marian Kaagh, Vice President of Environment quality and Safety at Energinet.

Citizen involvement rather than architectural competition
The idea of an architectural competition was soon taken off the table. This was because Energinet did not have a mandate to use electricity consumers’ money for a large-scale architectural competition, and because it would add extra time to what was already a tight schedule. Instead of inviting international architects to submit proposals for a landmark for the energy island, the approach was turned on its head:

“We soon realised that it would be much more interesting to invite the people who were going to be living with the substation for the next many years to suggest what they thought it should look like. We therefore decided to invite the islanders to participate in the work of designing the new substation,” says Marian Kaagh.

This marked the start of several meetings at which Energinet, together with its architects on the substation project, Arkitema, invited the islanders to contribute to the process of designing a station that would tie in with its surroundings in the best possible way.

“It’s an incredibly complex task building a substation like this. Much of the equipment has to be built from scratch, and there are numerous requirements regarding the electrical engineering and the entire substation structure. On top of which there is everything from security to sustainability that has to be taken into account, which only adds to the complexity. It was important for us that the participants were also aware that when we couldn’t just say yes to a good idea, it was because there were so many pieces that had to fall into place,” says Marian Kaagh.

Inspiration and concerns
At the same time, the purpose was to inspire those participating to give them an idea of what is actually possible, and how architecture can be used to either highlight or conceal the many thousands of square metres of buildings. Most importantly, the participants were given the opportunity to provide their input, ideas, concerns or wishes, which were compiled and analysed after the first workshop in December 2022.

“We received an incredible amount of constructive and interesting input. It ranged from a wild idea about combining the facility with a motorcross circuit to specific wishes that the substation be well-concealed through landscaping and vegetation. It gave us a very good idea of what people thought about the whole construction project. Those living close to the substation focus on mitigating noise and unsightliness. Others wanted us to use the buildings to support the narrative about the energy island, while a third group was more preoccupied with what could be done for the natural environment and biodiversity. It all gave us a good idea of what needed to be prioritised when designing the substation,” says Marian Kaagh.

In March 2023, Energinet presented a proposal for the design of the substation and the specific location in an area south of Aakirkeby – close to the water where the cables from wind turbines and the connections to Zealand and Germany will eventually come ashore. Energinet has now applied to the Regional Municipality of Bornholm for a district plan covering an area of 107 hectares for the technical installations and ample space to tailor the substation to its surroundings and screen it off with wide belts of trees.

“I really feel that we have created an exciting proposal for the design of the station which can shield the facility from neighbours in the area while at the same time giving something back to Bornholm and creating a connection to the landscape and the island’s special characteristics. From the outside, it may not appear that revolutionary, but for us it is quite radical to divide the station in two with a wetland area in-between,” says Marian Kaagh.

A common thread from input to finished substation
The question is whether the people on Bornholm who have participated in the process can recognise their input in Energinet’s proposal.

“It’s an impossible task to make everyone happy. However, this doesn’t mean that we shouldn’t try. For some people, issues about compulsory purchases or compensation obviously cause a lot of concern, and they obviously find it difficult to appreciate the value of the substation and the process we’ve been through. I understand this completely, and we’re trying to do what we can for them within the overriding framework. Having said that, I’m really pleased that we can see a clear and common thread from the input which has been provided to the solutions that we’ve chosen. Obviously, there are numerous wishes that we haven’t been able to accommodate, not least among those hoping that we drop the substation completely or place it out to sea,” says Marian Kaagh.

The Regional Municipality of Bornholm will now start work on preparing a district plan for the substation. The district plan is expected to be completed by mid-2024.

“We have now presented our ideas for the design of the substation. We will now work with the municipality to resolve the large number of specific challenges. At the end of the day, the Municipal Council decides the framework, but we feel that the work has got off to a very good start, as we have gone to great lengths to incorporate the input provided during the process,” says Marian Kaagh.


  • Technical area: 52 hectares
  • Total area: 107 hectares
  • Consultants: COWI
  • Architects: Arkitema
  • The task of constructing the substation is expected to be put out to tender in 2024.


Site plan: As a specific offshoot of all the input we have received, the large facility will comprise two areas, where the tall buildings will have sloping facades inspired by Ekkodalen’s unique topography.

Visualisation of the substation from the west. The visual impact of the buildings is reduced by the sloping facades and the belt of trees surrounding the substation.


Visualisation of facade. Cladding in natural colours.


Visualisation of wetland area between the buildings. Between the buildings, a wetland area will be established which follows the original route of a local stream, and which will be supplemented with water from roofs and building surfaces. Wooden bridges dispense with the need for boots in wet periods.

Visualisation of recreational area. The area around the substation is also a recreational area which creates space for greater biodiversity and allows visitors to come close to the ‘engine room’ of the energy island. The paths provide a route through the substation from the coast and north towards Aakirkeby.