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We finally have the go-ahead for TenneT

For months and months, Strukton Systems project manager Robert-Jan Koert has spent almost all of his time on the tender of TenneT for renovating 110-150kV high-voltage stations. With a good result: Strukton has won the bid. Robert-Jan speaks about the winning concept and what else may be in store.

There are 140 high-voltage stations of the 110-150kV type in the Netherlands, and they are all getting close to retirement age. Time for renovation, but there is more to it than replacing an old screw. The systems and methods have become obsolete. Transmission System Operator TenneT wants to try an entirely different approach altogether. This means testing, searching, trying out, and exploring. Of course, we do not want to do this with all high-voltage stations at the same time. Our power grid is crucial. It has to be up and running at all times. This is why TenneT has decided to have two lots with five high-voltage stations in total renovated, one by Strukton and one by Croonwolter&dros. Both companies have their own approach. The approach that proves to be best will be used for the high-voltage stations in the rest of the Netherlands.

No electricity by bus

In this tender, the bidders’ concept has to meet three important requirements: the design has to be modular, it has to become the new standard for the remaining high-voltage stations, and it has to be safe for the technicians working there. In addition, the time that the high-voltage station is out of service has to be as short as possible. It is true that an emergency power supply takes over the function of the transformer station, but it can only do so for a short period. Any delays in the renovation, therefore, would jeopardise the power supply. If activities take longer than expected in a railway scenario, the trains could drive on other tracks or passengers could be transported from A to B by bus a bit longer, but with electricity this is impossible.  In other words: reliability is a key aspect.

It is time for renovation, but there is more to it than replacing an old screw. The systems and methods have become obsolete

Robert Jan Koert

Families, businesses and farmers

Looking at the total picture, we hit upon the idea of using skids: frames with the high-voltage components mounted on them. We build the skids in advance and drive them to the installation with a special mover. This is fast, because all that is left to be done is installing the connections. Furthermore, it is safe. In the event of a malfunction, the skid can be removed and the technicians can repair or even replace it in a safe zone.
This is a huge order. The power supply itself as well as the software and its security are our responsibility. Additionally, we are working hard on environment management, which has quite a few challenges of its own: we have to think about residents in the vicinity, businesses, schools, and then there are the farmers who would very much appreciate if we take their hatching and mowing season into account. Challenges on all fronts, so to speak.


Fortunately, we have a lot of know-how at our disposal. Although Strukton Systems is the driver of this mega job, the project team includes colleagues from all corners of the Sanderink Holding. It is truly a multidisciplinary approach. Strukton Systems will be responsible for all high-voltage and control engineering work and for the development and implementation of the software. Antea Group is extremely knowledgeable about environmental and permit management. Strukton Rolling Stock will build the control boxes, and Strukton Civiel will be responsible for all civil engineering works, including excavation, the foundation, and site preparation. Having so much in-house knowledge is fantastic. This multidisciplinary collaboration is what makes us unique, something we hear from TenneT too.
We also impress our client with our railway knowledge. Of course, overhead lines and high-voltage stations are two different things, but they also have some common ground. This knowledge is a great help. TenneT is also happy that we think in terms of scenarios. If we meet with a certain setback, we know exactly which solution we have to use and what we need from TenneT. The client is very pleased about this; it inspires confidence.

“The schedule is ambitious – and that is putting it mildly. By the end of next year, the renovation will have to be completed”

Full steam ahead

After all those months of brainstorming, consultations, marking down, pre-presentations, going back to the drawing board, presenting and waiting, the moment has finally arrived that we can go ahead. Actually, it is full steam ahead, for the schedule is ambitious – and that is putting it mildly. By the end of next year, the renovation will have to be completed. The actual construction takes about three to four months, which means it should start in September next year. This leaves twelve months for the design and the preparatory work: the design phase, setting up a hall for production of the skids and the control boxes, integrating TenneT’s components, developing the software, applying for permits, constructing a test model; we will have to go all out. But I have every confidence in our ability to accomplish this.

Besides the renewal of de high-voltage substations, we also replace the 150kV substation in Alphen aan de Rijn

Virtual Reality Experience - Replacement substation

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Strukton to renovate TenneT high voltage substations

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