Baltic Storage Platform has inaugurated the 200MWh Hertz 1 battery energy storage system in Kiisa, developed through a joint venture between Evecon, Corsica Sole and Mirova.
The facility is the first of two 100MW/200MWh projects designed to support grid stability following the Baltics’ synchronisation with the European continental power system, the partners said.
The project was backed by €85.6m in financing from the European Bank for Reconstruction and Development, the Nordic Investment Bank and Edmond de Rothschild Asset Management.
Commissioning of Hertz 1 strengthens Estonia’s energy independence by providing fast-response frequency regulation services. The BESS is designed to operate across multiple power and ancillary service markets, including FCR, aFRR, mFRR, intraday and day-ahead.
By charging during periods of low prices and discharging during peak demand, the system is also expected to help reduce price volatility for consumers.
Estonia’s minister of energy and the environment Andres Sutt said the project demonstrates 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 Evecon chief executive Karl-Joonatan Kvell.
“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 around 25km from Tallinn, the project includes a high-voltage connection to the 330kV transmission network via an underground cable and comprises 54 containerised units housing 2,328 battery modules.
Baltic Storage Platform said the development was enabled through close cooperation with transmission system operator Elering, with industry partners including Yuso, Connecto, Energel and Nidec Conversion supporting 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, said storage is a “critical link” for the Baltics, adding that Hertz 1 shows grid-scale battery systems are now “bankable at scale”.
Construction of the sister project, Hertz 2 in Aruküla, is under way, with both units due to be completed by the end of 2026.
