Single Overhead Line Considered for Saaremaa Section of Fourth Estonia–Latvia Electricity Interconnection Instead of Two

The Ministry of Economic Affairs and Communications, as the developer of the national designated spatial plan, proposed to Elering that the fourth Estonia–Latvia electricity interconnection on Saaremaa be evaluated for implementation as a single overhead line instead of two as previously planned. Elering considered the proposal and offered a solution for how this could be made possible. The ministry will decide in the coming weeks how many overhead lines will be pursued.

“In February this year, we held public engagement meetings about the national spatial plan for the fourth Estonia–Latvia electricity interconnection, aimed at informing local residents and interested parties,” said Monika Korolkov, Planning Adviser at the Ministry of Economic Affairs and Communications. “We introduced the spatial planning process and presented the alternative corridor routes for the interconnection, as well as the principles behind route selection.
We visited five municipalities on the mainland, as well as Muhu Island and Saaremaa. We received a great deal of feedback—around 300 pages in total. Among the many suggestions, one of the most prominent messages from Saaremaa residents was a clear preference for fitting the planned electricity interconnection into a single existing corridor, rather than constructing two separate 330-kilovolt overhead lines.
This type of feedback—both during and after the engagement meetings—was exactly what we needed at this stage to help identify the best possible solution. Therefore, we proposed to Elering that they assess whether the goals of the spatial plan could also be achieved with just one 330-kilovolt line between Saaremaa, the new substation in Lihula, and the new substation on the mainland, and under what conditions and risks such a solution would be feasible,” Korolkov explained.

“We thoroughly analysed the proposal and concluded that—considering Elering’s obligation to find the most economically sound solution for the development of the electricity system and updated information gathered during the planning process—reducing the scope of overhead lines on Saaremaa to a single 330-kilovolt line is a viable option,” said Priit Heinla, Head of Offshore Grid Development at Elering.
“Since the application for the national spatial plan was submitted in October 2023, the Latvian side of the project has become clearer, planning procedures have been initiated there, the strategy for achieving Estonia’s renewable energy targets has been further defined, and the legal framework regulating transmission system operations has evolved,” Heinla noted. He added that while the single-line solution does carry some technical risks, they have largely been mitigated.

“If the decision is made to proceed with a single overhead line, the next step will be to revise the currently outlined corridor between Lihula and the western coast of Saaremaa, shifting from a dual-line to a single-line concept. The planning brief will also be adjusted accordingly, allowing us to launch various studies required for environmental impact assessment. To determine the best routing alternative, we will conduct the necessary studies, compare options, and evaluate impacts,” Korolkov said, outlining the next steps in the planning process.
“This change will slightly affect the current schedule and delay the results by a few months. Therefore, we no longer expect to identify the optimal corridor by the end of this year but rather at the beginning of next year,” she added.