Elering activates key power connection for synchronization

Elering activates key power connection for synchronization. Photo: Margus Ansu

The Estonian state-owned transmission system operator (TSO) Elering has successfully completed the reconstruction of the 330-kilovolt Viru-Tsirguliina overhead power line, a crucial part of the large-scale synchronization project with continental Europe.

Elering said that this is one of Estonia's largest and most significant physical infrastructure projects necessary for the synchronization. The connection was activated on Tuesday, Nov 5. The total cost of the Viru-Tsirguliina project was approximately 86.5 million euros, with 75 percent of the investment for the synchronization project funded by the European Union's Connecting Europe Facility, while the remaining 25 percent is covered by congestion fees collected in Estonia.

Reconstruction work on the line began in June 2023 and was completed in October this year, with some final landscaping still in progress. The project involved upgrading a 244-kilometer high-voltage overhead line, replacing outdated Soviet-era conductors and towers with modern structures. The reconstruction freed up approximately 50 hectares of land within the protected zone.

At the peak of the project, around 250 contractors were working along the entire line. A total of 257 towers were installed on the Viru-Mustvee section and 469 towers on the Mustvee-Tsirguliina section, with 726 towers installed in total. The main contractors for the construction work were Leonhard Weiss OÜ and Enersense AS.

Hannes Kont, Elering's project and synchronization manager, explained that after disconnecting from Russia's power system, a strong north-south power connection must remain within the Baltic region.

«Abundance of transmission lines and high transfer capacities gives us confidence that we can prevent a domino-like line shutdown or complete separation caused by overload,» he said.

Kont added that with the activation of the Viru-Tsirguliina connection, all major infrastructure investments have been completed, leaving only the finalization of control and monitoring systems, after which a separation test and disconnection from Russia's power system will take place.

On Feb. 8, Baltic system operators will desynchronize the Estonian, Latvian, and Lithuanian power systems from the Russian synchronous area. This will be followed by an island mode test to assess the operational capacity of the three Baltic states' power systems. Synchronization with continental Europe's frequency area is planned for Feb. 9.