Today, electricity is a self-evident asset that enables the functioning of society and the economy. However, behind every light turned on by a light switch, there is a complex power system that needs to be taken care of, maintained and developed daily to cope with any challenges that may arise. In Slovenia, this role is taken on by ELES, the combined transmission and distribution system operator.
The beginnings of electricity transmission in Slovenia go back more than a century when electricity was transmitted from its source at the Fala Hydroelectric Power Plant to the Laško substation (77km) via a new two-system 80 kV transmission line. This was the first time long-distance transmission was made possible in Slovenia and the wider region. The transmission was not only an exceptional engineering and social achievement of its time but also a turning point that marked the beginning of electrification in the country and paved the way for the industrial revolution in our area.
A century of transmission network operation also means constant updates and adjustments, as the grid must keep up with growing consumption, technological advancements, and increasingly stringent requirements to ensure stability and reliability. Projects such as the construction of the two-system 400kV Cirkovce-Pince transmission line or the reconstruction of the 110kV Divača-Pivka-Ilirska Bistrica transmission line are only a few examples of continuous investments in the improvement of the existing system. An important part of our investments is also directed toward smart grid projects, like SINCRO.GRID, NEDO and GreenSwitch, as well as research and development projects, such as FutureFlow, Osmose and TwinEU. In addition, through continuous monitoring and the use of advanced technologies, ELES ensures that potential errors are detected and resolved before they can affect system operation. Investments in digitalization and automation enable better transmission management and optimization, contributing to greater stability of the electric power network. Of course, the Slovenian power network is not an isolated system – on the contrary, it is closely connected to the networks of neighbouring countries and is therefore a part of the overall European electricity space. ELES works closely with neighbouring system operators, is active in numerous regional and international associations, and participates in international consortia looking for solutions to the most demanding challenges in the energy sector. Only a successful international cooperation can ensure a stable operation of the European energy system.
Natural disasters, such as the catastrophic 2014 ice storm, tested the resilience of the electric power system. When snow and ice loads broke the power lines, teams worked around the clock, regardless of the extremely difficult situation. Despite the enormous damage, ELES rehabilitated the network and restored the supply of the most affected areas in the shortest time possible, with a swift response and exceptional efforts. This event demonstrated how crucial the systems’ resilience is and confirmed that contingency plans and staff readiness are of paramount importance.
ELES also confronted the unique challenge of ensuring the reliability of the system’s operation during the COVID-19 pandemic. During the first wave, when there were many unknowns, we completely isolated the dispatch teams in shifts for 14 days to maintain the stability of the energy supply. When the world stood still due to the pandemic, the employees of the Republic Management Center, isolated from their families and loved ones, ensured that the Slovenian electric power system remained fully operational.
When discussing electricity, we often forget how much work and effort it takes to ensure it is always available. Electricity is not just a commodity but the foundation of modern life, powering industry, healthcare, and transport, as well as everyday aspects of life, such as cooking, phone charging, or internet use. In the last 100 years, we have proven our ability to adapt, evolve, and ensure stability even in the most difficult times. And we will continue to do so.
Written by: Nadja Novak and Laura Zelensek, ELES
