Hertz 2, a new pillar of energy storage in Estonia
Located in Aruküla, around twenty kilometres from Tallinn, the Hertz 2 energy storage facility is a direct continuation of the Hertz 1 project. Together, these two infrastructures form one of the largest battery storage complexes in continental Europe and play a central role in securing and modernising the Baltic electricity system.
With Hertz 2, the Baltic Storage Platform strengthens the Estonian grid’s ability to integrate large volumes of renewable energy while ensuring stability following the recent synchronisation of the Baltic States with the European electricity grid.
A strategic project for Baltic grid stability
Designed to deliver essential system services, Hertz 2 will contribute to frequency stabilisation, grid balancing and the management of fluctuations in solar and wind power generation.
By storing electricity during periods of surplus and instantly releasing it when demand increases, the facility helps maintain a constant balance between electricity production and consumption. This role is all the more strategic as the Baltic grid continues its gradual phase-out of fossil-fuelled thermal power plants.
A key lever for regional energy independence
Hertz 2 fully aligns with the ambition of Estonia and the Baltic States to strengthen their energy sovereignty. By reducing dependence on fossil fuel imports and supporting the development of a low-carbon electricity mix, the project directly contributes to the resilience of the regional energy system.
Combined with Hertz 1, the facility will contribute to a total installed capacity of 200 MW and 400 MWh of storage, making the Hertz complex one of the most significant battery hubs at European level.
A European alliance dedicated to large-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 player in Estonia
Corsica Sole, a French pioneer in large-scale energy storage
Mirova, an international investor specialising in sustainable finance
This European cooperation brings together industrial expertise, technological innovation and responsible financing around a shared objective: to build robust storage infrastructures compatible with the requirements of the European electricity grid.
A landmark financing for battery storage
Hertz 2, alongside Hertz 1, benefits from a landmark financing package of €85.6 million, 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 in the Baltic States structured exclusively on revenues generated by energy storage assets. Supported by an InvestEU guarantee from the European Union, the transaction marks a major recognition of battery storage as a mature and bankable asset class.
Construction underway, focused on the future
Currently under construction, the Hertz 2 facility is expected to enter operation by the end of 2026. It will complement the services provided by Hertz 1, which is scheduled to be energised in autumn 2025, ensuring broader coverage of the Baltic grid’s needs in terms of flexibility and security.
A model for future European infrastructure
Like Hertz 1, Hertz 2 goes beyond its industrial dimension. The project illustrates the growing role of battery storage as a cornerstone of decarbonised and resilient electricity systems.
By combining technological innovation, European cooperation and sustainable financing, Hertz 2 establishes itself as a replicable model for the development of large-scale storage infrastructure, set to play a decisive role in Europe’s energy transition.
Corsica Sole has built its storage expertise in French island territories and in Belgium. With Hertz 1 and Hertz 2, we are bringing this unique know-how to support European grid stability and the energy sovereignty of the Baltic states.”
For Estonia, Hertz 1 and Hertz 2 are more than projects: they are strategic infrastructures that prove the energy transition is tangible. The imminent commissioning of Hertz 1 shows this financing is backing a real-world project already under construction.
Mirova, who has been supporting these projects since 2024, is proud to be part of this partnership with Corsica Sole and Evecon. This closing with such reputable lenders demonstrates the bankability of large-scale energy storage, Hertz 1 and Hertz 2 in Estonia, and paves the way for a new generation of low-carbon infrastructure.
