Evecon, Mirova and Corsica Sole Inaugurate First of Two 100MW/200MWh BESS in Estonia

Why It Matters

The project proves that private capital can quickly mobilise large‑scale storage to stabilise the newly integrated Baltic grid and accelerate the region’s renewable transition.

Key Takeaways

• 100 MW/200 MWh BESS inaugurated in Estonia.
• Supports FCR, aFRR, mFRR, intraday, day‑ahead markets.
• Ancillary service prices enable 20‑30% IRR for early projects.
• Funded by EBRD, NIB, Edmond de Rothschild.
• Hertz 2 expected 2026, expanding Baltic storage capacity.

Pulse Analysis

The Baltic states’ 2025 break‑away from the Russia‑led BRELL network and their subsequent synchronization with the European grid created a sudden demand for fast‑acting balancing resources. Frequency‑containment and restoration reserves, once supplied by conventional generators, now require sub‑second response times that only battery storage can reliably provide. As a result, ancillary‑service markets have surged, delivering premium prices that make high‑capacity BESS projects financially attractive and strategically essential for grid reliability.

Hertz 1’s launch underscores a broader shift toward private‑sector financing of energy infrastructure in the region. Backed by the European Bank for Reconstruction and Development, the Nordic Investment Bank and Edmond de Rothschild, the venture secured a financing package that reflects confidence in the projected 20‑30% internal rates of return. This level of return, driven by soaring reserve prices, signals to investors that large‑scale storage is no longer a niche asset but a core component of the Baltic power market’s economics, encouraging further capital inflows and competitive development.

Technologically, the Hertz 1 installation uses a containerised architecture—54 modules each roughly 4 MWh—integrating expertise from Yuso, Connecto, Energel and Nidec Conversion. This modular approach shortens construction timelines and simplifies scaling, paving the way for the upcoming Hertz 2 project slated for late‑2026. Together, the two 100 MW facilities will more than double Estonia’s battery capacity, bolstering energy sovereignty, smoothing renewable intermittency, and positioning the country as a testbed for next‑generation grid‑balancing solutions in Central and Eastern Europe.