Göteborg upgrades its city grid

In Sweden’s second largest city of Göteborg, part of the city power grid was reaching the end of its technical lifetime. Power utility Göteborg Energi had experienced some breakdowns and problems, so it needed to upgrade. As part of a larger upgrade project, it needed to replace 94 kilometres of first-generation PEX cables with new cables.

“Projects of this importance have not been done since the beginning of laying cables in Göteborg,” says Roger Vikmo, project manager at Göteborg Energi. “It’s a first of its kind in modern times. Everything was cabled in the ‘60s. That’s the grid we’re now removing.”

He says that of the many challenging factors in such a project, one of the most important is logistics.

“You have to have the right materials when you need them. Downtime is enormously expensive when you close down large areas. Everything has to be there on time. Deliveries have to arrive as planned.”

Add to that the challenge of a modern, changed city since the cables were first installed. “We haven’t done anything like this since the mid-‘70s. The environment has changed. There’s a lot more traffic. And many more people moving around in the areas where we’re working.”

His colleague, Marcus Gustafsson, power grid project manager at Göteborg Energi, adds, “When we’re digging down so much cable, the street is already full of installations. There isn’t much room. The majority of sections are very cramped. The network is operating, and we have to install a new one of similar size. It’s quite challenging.”

Göteborg Energi offered a public tender for the project. Technical wholesale supplier Onninen joined NKT to put in a bid. “It was natural for us to contact NKT in this case,” says Roger Johannson, salesman with Onninen. “NKT is our number one when it comes to cable jobs.” The team won the order.

“At the kick-off meeting, Göteborg Energi emphasized the importance of exact cable lengths and markings on the drums,” says NKT Swedish wholesale sales engineer Mikael Åkerlund. “Unloading had to be done in certain ways so they could handle the drums smoothly on site.”

Lead time from initial order to first delivery was five weeks. And this was happening in the first several months of 2020 – just as the global Covid-19 pandemic had spread to Europe.

Onninen and NKT tackled the challenges in close cooperation. They worked with transportation specialists Kesko Sverige AB to handle logistics between NKT’s manufacturing plant in Falun, Sweden, and the installation sites in Göteborg. Erik Ljungstedt, Kesko Transport Developer, says he had close dialogue with Göteborg Energi for timing on when they needed which cable drums and where. He also kept a continuous dialogue with NKT Falun’s Customer Service Centre (CSC) for deliveries and timing. “It worked very well,” says Erik Ljungstedt. “You develop good relations with the people you talk to.”

And Göteborg Energi is satisfied with the deliveries. “We received everything we wanted on time,” says Roger Vikmo. “Despite these corona times, we’ve received everything. That is critical for us. If the materials don’t reach us, the project stops.

“We’re also satisfied with the drum markings from the factory,” he continues. “Logistics worked well when distributing the cables for the various stages. There were no problems. It’s been exemplary.”

Onninen highlights the cooperation among all parties in the project. “This is one of the biggest cable projects we’ve done,” says Onninen’s sales engineer Roger Johannson. “We did this project very well together with NKT. I’m proud that Göteborg Energi felt confident that we could deliver. I’m proud we managed this.”