The Baltic Storage Platform has inaugurated the 200MWh Hertz 1 battery energy storage system in Kiisa as part of a joint venture between Evecon, Corsica Sole and Mirova.
The facility is the first of two 100MW/200MWh projects designed to stabilise the regional power system following the Baltics’ synchronisation with the European continental grid, the partners said.
The project was backed by €85.6 million in financing from the European Bank for Reconstruction and Development, the Nordic Investment Bank and Edmond de Rothschild Asset Management.
The commissioning of Hertz 1 strengthens Estonia’s energy independence by providing rapid-response frequency regulation services.
The BESS is designed to operate across multiple electricity and ancillary service markets, including FCR, aFRR, mFRR, intraday and day-ahead.
By storing power when costs are low and releasing it during high demand, the project also helps ease price volatility for consumers.
Estonia’s minister of energy and the environment Andres Sutt said the project proves that “private investors are capable and interested in backing large energy projects in Estonia” and that “the future is here”.
“From today, Estonia’s energy security is significantly stronger,” said Karl-Joonatan Kvell, chief executive of Evecon.
“Hertz 1 is a critical piece of infrastructure that allows us to manage our energy sovereignty with confidence while accelerating the transition to clean, renewable energy.”
Located 25km from Tallinn, the project includes a high-voltage connection to the 330kV transmission network via an underground cable and uses 54 containerised units housing 2328 battery modules.
Baltic Storage Platform said the development was enabled by strong cooperation with transmission system operator Elering.
Industry partners including Yuso, Connecto, Energel and Nidec Conversion supported engineering, system integration and commissioning.
“Hertz 1 demonstrates Corsica Sole’s ability to deliver complex, large-scale battery storage solutions in highly demanding technical environments within an ambitious and tightly managed project timeline,” said Corsica Sole chief executive Michael Coudyser.
Raphaël Lance, global head of private assets at Mirova, commented that “storage is the critical link” for the Baltics and that Hertz 1 shows grid-scale systems are “bankable at scale”.
Construction of sister project Hertz 2 in Aruküla is under way and both units are due to be completed by the end of 2026.