Holtab acted as turnkey substation supplier to Umeå Energi for a new 12 kV secondary substation on Stora Fjäderägg, part of the Holmön island electricity link. Holtab engineered a specially adapted TSK 315–3 network station with space for a backup generator, compliant with EBR KJ59 and designed for remote supervision and control. The company manufactured and assembled the substation at its Tingsryd facility, transported it by barge from Umeå together with associated cabling, and then moved it across the island for installation on a new site independent of the former lighthouse building. Holtab completed construction and commissioning as part of Umeå Energi’s project to modernise and secure the power supply between Holmön and Stora Fjäderägg, including renewal of associated sea and land cables.