NamPower energises new N$ 394 million Sekelduin Substation

STAFF REPORTER
  • 16 Hours Ago
NamPower successfully commissioned and energised its new indoor 132/66/33 kV Sekelduin Substation, located east of Swakopmund, on 24 September 2025. The Sekelduin Substation is distinguished as the first fully digital substation on the African continent, with a total project investment of N$ 394 million.



This newly commissioned infrastructure added to the NamPower transmission network unlocks coastal load growth, strengthens reliability, and future-proofs the Erongo region grid with a digital substation employing process bus application in accordance with IEC 61850 standards. The substation uses Mixed Technology Switchgear (MTS), compact hybrid AIS/GIS, plus Metal Enclosed GIS at 33 kV, with ACTOM as the principal equipment supplier and integrator.



The Sekelduin Substation is fed from the existing Kuiseb Substation which is approximately 35 km south-east of Sekelduin with two parallel 132kV overhead power line architecture, improving the N-1 robustness and reducing single contingency exposure on coastal nodes.



The digital substation design employs process and station bus, which reduces copper cable runs, improves remote asset monitoring, enhances fault location accuracy, and strengthens cyber-secure SCADA integration, addressing both performance and copper-theft risks. The digital application also provides a platform for future AI/ML integration, positioning NamPower among the top utilities in the world.



Core to the secondary system design is the hybrid architecture that integrates digital and conventional hard-wired protection systems based on IEC 61850. The IEC 61850- 9-2LE based main protection system comprises a redundant process and station bus via merging units/ process interface units, utilising sampled values and GOOSE communication. The backup protection system features a station bus and GOOSE, with hardwired connections to conventional CTs and VTs.



The now commissioned and energised Sekelduin Substation will function as a 132/66/33kV indoor switching station making use of compact mixed technology gas-insulated switchgear (MTS) for the 132kV and 66kV circuits, while the 33kV circuit makes use of gas-insulated fixed-pattern metal-enclosed switchgear. The substation will feature two voltage transformation levels derived from the 132kV busbar: 66kV and 33kV. The high-voltage (HV) equipment is housed indoors in a custom-designed building, in conjunction with SCE Consulting Engineers and TDx Power and constructed by Nexus Building Contractors. This is to protect the equipment from the highly corrosive environments of the marine and desert regions.