In the scenic landscape of Slovenia’s northern Primorska region, the reconstruction of the 2×110 kV Gorica–Divača transmission line included the creation of a key energy link at the Renče point. This project is part of Slovenia’s broader strategy to modernise its power infrastructure and connects substations 110/20/20 kV Sežana and 110/20 kV Vrtojba, forming the so-called Northern Primorska loop.
Project Summary
The project includes the installation of 1,400 meters of underground cables beneath the village of Renče and the reconstruction of 355 meters of the existing transmission line. This significantly enhances system stability and resilience against adverse weather conditions.
Additionally, by implementing new protection systems and advanced SCADA equipment, the project ensures improved control and monitoring of the network, enabling faster fault response and maintaining high efficiency in power transmission.
Technical Characteristics
- Transmission line voltage: 110 kV
- Length of reconstructed overhead line: 355 m
- Length of new underground cables: 1,400 m
- Connected substations: 110/20/20 kV Sežana and 110/20 kV Vrtojba
- Cable equipment type: High-voltage 110 kV cable systems and cable terminations
- Installation of steel structures and OPGW
Project Challenges
- Adapting the terrain for underground cable installation while preserving existing overhead infrastructure.
- Coordinating overhead line works to ensure smooth integration with underground cable installation.
- Operating in a densely populated area, requiring precise planning and minimal disruption to electricity supply.
- Integrating new protection and control systems, including high-tech OPGW and SCADA solutions.
- System testing and optimisation to ensure maximum grid stability and long-term reliability of the power infrastructure.
Elnos Group’s Role
Our member company, ENS Slovenia, played a key role in project delivery:
- Preparation of the technical documentation and supply of cable equipment
- Electrical assembly works on 110 kV high-voltage cable systems
- Installation of 110 kV cable terminations
- Installation and integration of steel structures and OPGW systems
- Testing and commissioning of the entire system in accordance with the highest standards of safety and stability
Strategic Importance
- Strengthening the power grid in the northern Primorska region
- Increasing supply stability and transmission system security
- Reducing the visual impact of overhead lines by transitioning to underground cables
- Enhancing network resilience to weather events through modernised infrastructure
- Supporting Slovenia’s energy transition toward advanced transmission technologies
- Enabling improved integration of new renewable energy sources
The reconstruction of the 110 kV Renče transmission line represents a vital step in modernising Slovenia’s power system, ensuring long-term stability and security of electricity supply for the region’s population and industry.
