Prefabricated station improves in Dalarna

For Dala Energi, the pace of upgrading the electricity grid is high. Using a ready-built primary substation from Holtab saves both time and money. “We are very satisfied with how quick it went and its higher quality,” says Lars Jonsson, project manager at Dala Energi.

In their efforts to modernise the electricity grid in Dalarna, Dala Energi will renovate or build a large number primary and secondary substations.

”For most people in our area, it is a matter of course to have access to reliable electricity around the clock. We are working hard to have a robust electricity grid,” says Jonsson.

Lars Jonsson at Dala Energi is satisfied with the station built in Gustafs by the Dalälven river. Photo: Dala Energi

At the time of writing, Dala Energi has modernised three stations. Two of them were built on site, and the third came from Holtab’s factory in Tingsryd. It is in Gustafs, which is part of the municipality of Säter and is located on the Dalälven river.

“We were eager to try out a prefabricated solution, and in Gustafs the conditions were right,” says Jonsson.

Connected buildings

In Gustafs, the transformers are located outside, while two switchboards (one 20 kV and one 10 kV) and the associated control room are located inside Holtab’s station – which is divided into three fire zones.

”We proposed that they connect two of our stations. These are thirteen metres long and over three metres deep inside. This gave us enough space for the equipment and the highest level of safety thanks to the three different fire zones,” says Andreas Öberg, sales engineer at Holtab.

Holtab’s prefabricated solution means that Dala Energi can work faster with shorter construction time on site. Photo: Dala Energi

The stations were tested fully assembled in the Holtab factory. They were then dismantled, transported and reassembled on site in Dalarna. The work in Gustafs, including final testing, took less than two weeks.

“Holtab took responsibility for joining the buildings together and connecting them electrically,” says Andreas Öberg.

Easier logistics

An advantage of Holtab’s concept is the reduced time it takes on site to build the stations. For Dala Energi, this meant cost savings and fewer logistical challenges.

“We don’t have to deal with the elements, and there’s no hassle with crowded sites or road closures,” says Jonsson.

Dala Energi emphasises how easy it was to cooperate with Holtab and that they managed to keep the schedule.

”We have had a great dialogue, and now that the electricity is up and running, the personnel working at the station sound happy. We are eager to implement the concept at more stations,” says Jonsson from Dala Energi.

There are two switchboards and a control room in the station. Photo: Dala Energi

Challenge:

Dala Energi future-proofs the electricity grid in Dalarna. For projects to be time- and cost-efficient, smart solutions are important in renovating or building new stations.

Solution:

Holtab’s ready-built primary substations shorten the construction time on site. This means greater safety for those working there as less work needs to be done in an electrical environment. Instead, it takes place in controlled forms at Holtab’s factory. Holtab has supplied 12 kV and 24 kV primary switchboard, which are located inside the Holtab station with its three fire zones.

Details:
Nominal voltage: 12 kV and 24 kV
Rated current: 1600 A and 1250 A

Additional delivery of:
General electricity, heating and ventilation
Lighting/emergency lighting
Fire alarms
LS system 110 VDC
VHC 400 VAC with automatic switching
Testing and commissioning
Testing of delivered equipment

Outcome:

Residents, municipal services, and companies in Gustafs in Säter municipality now get future-proof electricity. Dala Energi continues to work on new projects, including building new primary substations using prefabricated solutions.