Hertz 2: A New Cornerstone of Energy Storage in Estonia

Located in Aruküla, around 20 kilometres from Tallinn, the Hertz 2 battery energy storage facility builds directly on the success of the Hertz 1 project. Together, these two facilities form one of the largest battery energy storage hubs in continental Europe and play a central role in strengthening and modernising the Baltic power system.

With Hertz 2 now in operation, the Baltic Storage Platform further enhances the Estonian grid’s ability to integrate large volumes of renewable energy while ensuring system stability following the recent synchronisation of the Baltic States with the European electricity grid.

A Strategic Asset for Baltic Grid Stability

Designed to provide essential ancillary services, Hertz 2 contributes to frequency regulation, grid balancing and the management of fluctuations in solar and wind power generation.

By storing electricity during periods of surplus generation and releasing it instantly when demand increases, the facility helps maintain a continuous balance between electricity supply and consumption. This role is becoming increasingly important as the Baltic power system continues its transition away from fossil fuel-based generation.

A Key Driver of Regional Energy Independence

Hertz 2 fully supports the ambition of Estonia and the Baltic States to strengthen their energy sovereignty. By reducing dependence on fossil fuel imports and supporting the expansion of a low-carbon electricity mix, the project directly contributes to the resilience of the regional energy system.

Combined with Hertz 1, the facility brings the total capacity of the Hertz complex to 200 MW of power and 400 MWh of energy storage, making it one of Europe’s largest battery storage hubs.

A European Partnership Driving Utility-Scale Energy Storage

Like Hertz 1, the Hertz 2 project is developed by the Baltic Storage Platform (BSP), a joint venture bringing together:

• Evecon, a leading renewable energy developer in Estonia;
• Corsica Sole, a French pioneer in utility-scale battery energy storage;
• Mirova, an international sustainable investment company.

This European partnership combines industrial expertise, technological innovation and responsible financing around a shared objective: developing robust energy storage infrastructure that meets the requirements of the European electricity system.

Landmark Financing for Battery Energy Storage

Together with Hertz 1, Hertz 2 benefited from a landmark €85.6 million financing package provided by the European Bank for Reconstruction and Development (EBRD), the Nordic Investment Bank (NIB), and Edmond de Rothschild Asset Management.

This represents the first project financing transaction in the Baltic States structured exclusively around revenues generated by battery energy storage assets. Supported by an InvestEU guarantee from the European Union, the transaction marks a major milestone in recognising battery storage as a mature and bankable asset class.

Now Fully Operational

Now in operation, Hertz 2 complements the services already provided by Hertz 1, delivering additional flexibility, stability and security to the Baltic electricity grid. Together, the two facilities support the growing integration of renewable energy while providing the real-time balancing services required for a reliable power system.

A Model for Future European Energy Infrastructure

Like Hertz 1, Hertz 2 goes beyond its industrial significance. The project demonstrates the growing role of battery energy storage as a cornerstone of resilient, decarbonised electricity systems.

By combining technological innovation, European cooperation and sustainable financing, Hertz 2 stands as a replicable model for the development of large-scale battery storage infrastructure that will play a decisive role in Europe’s energy transition.