Tetas has signed a contract with Litgrid to carry out the design works for a controlled shunt reactor in Western Lithuania, at the Darbėnai switchyard. This will be the second device of its kind in Lithuania and will help ensure the quality of electricity supply by regulating voltage and reactive power in the transmission network.
Tetas specialists will prepare design proposals for connecting the controlled shunt reactor, obtain the construction permit, and develop the technical design documentation. The contract value amounts to EUR 184,000. The design work is scheduled to be completed by November this year.
These devices will ensure the quality of electricity supply by regulating voltage and reactive power while also reducing technological losses in the transmission network. Installation and commissioning of the controlled shunt reactor are planned to continue until the end of 2028.
“The Darbėnai switchyard is our starting point for strengthening interconnections with Latvia. In the future, this uniquely designed switchyard could become a hub connecting offshore wind farms and potentially even new offshore interconnectors. As Lithuania continues to break records in renewable energy generation, ensuring stable voltage control in the grid is becoming increasingly important. Therefore, the installation of a controlled shunt reactor here is particularly necessary – it will help maintain reliable system operation and prepare the grid for even larger flows of green energy,” says Andrius Šemeškevičius, CEO of Litgrid.
Currently, Lithuania operates one 330 kV controlled shunt reactor with a reactive power capacity of 180 MVAr at the Lithuanian Power Plant transformer substation. In addition to this reactor, the Lithuanian system includes 11 lower-capacity shunt reactors; however, they are not controllable and their impact is limited to local sections of the grid.
The objective of the Interconnection Reinforcement Program is to increase cross-border electricity transmission capacity between Lithuania and Latvia by constructing a new transmission line, upgrading existing electricity transmission lines, and strengthening the related internal transmission network infrastructure. The program will also interconnect the eastern and western parts of Lithuania’s electricity system, thereby ensuring greater energy security, reliable electricity transmission, and more stable system operation, while creating conditions for further integration and development of renewable energy sources.
The program includes the construction of three new 330 kV electricity transmission lines (Darbėnai – Varduva – Mūša, Panevėžys – Mūša, Varduva – Broceni), the construction of the 330 kV Varduva transformer substation, installation of shunt reactors at the 330 kV Darbėnai and Mūša switchyards, and the reconstruction of six existing 330 kV transmission lines (Darbėnai – Grobinė, Panevėžys – Jonava, Lietuvos Elektrinė – Jonava, Šiauliai – Mūša, Panevėžys – Aizkrauklė, Mūša – Viskali).
Once the program is completed, the Lithuania–Latvia cross-border electricity transmission capacity will increase from 1,250 MW to 2,250 MW. It will also enable the connection of an additional 1,100 MW of onshore wind, 800 MW of solar, and 2,400 MW of offshore wind capacity to the transmission grid. The program is planned to be completed by 2034.
