Siemens, its Fluence storage joint venture with US power group AES, and Lithuania’s transmission system operator Litgrid plan to build a first project in the Baltics that links battery energy storage directly to the power grid to help the Baltic nation move away from Soviet-era energy ties towards an integration with EU countries.

A 1MW pilot plant near the capital Vilnius will serve as proof-of-concept for much larger planned projects in the former Soviet republic as Lithuania is quickly expanding renewable energies to become independent of Russian fossil gas and integrate with the Continental European Synchronous Area in 2025.

The project uses the concept of ‘virtual transmission lines’ (VTL) that places energy storage along a transmission line to inject or absorb real and reactive power, mimicking transmission line flows.

“As the Lithuanian TSO, we are in a unique position. As others, we also face the challenges of the shift to renewable energy, but at the same time we are doing a synchronisation project, which is the switch from our current operation in the post-Soviet grid to an independent cooperation with our partners in Europe,” said Litgrid chief executive Rokas Masilius.

“This, combined with a system that currently heavily relies on electricity imports, means that we have to be bolder and seek innovative solutions: that’s why we are looking at battery energy storage at the transmission level.”

Lithuania targets to boost the renewable power share in its grid from a current 20% to 45% in 2030, and nearly 100% in 2050. However, high penetration of non-synchronous renewable generation is likely to present power system stability challenges in the areas of frequency, voltage and stability, which storage linked directly to the power grid is trying to mitigate.

The pilot project with Fluence is Lithuania’s first grid-scale battery energy storage system, and will be among the first VTL projects in Europe to be tested.

“VTL is one of the most exciting applications for battery energy storage. We’re proud to work with a forward-thinking TSO like Litgrid and our partner Siemens to demonstrate the benefits of storage as a transmission asset,” said Fluence chief executive Manuel Perez Dubuc.

As part of its energy independence plan, the small Baltic nation has also announced a plan to hold a tender for a 700MW offshore wind project off its coast in 2023.

State-controlled Lithuanian utility Ignitis Group (formerly known as Lietuvos Energija) last year has linked with Engie-EDPR joint venture Ocean Winds to develop a €1.5bn ($1.77bn) offshore wind project in the Baltic Sea for the tender.