Tallinn-based Energiasalv announced it secured the construction permit from the country's Consumer Protection and Technical Regulatory Authority to build a 550 MW pumped hydro storage facility in Paldiski, on the Pakri Peninsula of northwestern Estonia.

“We will continue with the pre-qualification for the construction procurement at the beginning of February,” the company's CTO,  Sander Astor, said in a statement. “We aim to finalize the tender process by the end of 2023 and start construction on the project in the summer of 2024.”

The development of the project began in 2009 and in 2012 it was included in the 10-year network development plan drafted by the European Network of Transmission System Operators (Entso-E). The company conducted then the environmental assessment and environmental studies between 2016 and 2018, with the geological investigations having been done between 2019 and 2021.

The storage facility is planned to have a storage capacity of 6 GWh during one storage cycle of 12 hours.

According to Entso-E, the project is based on a semi-loop concept, with the upper reservoir being the Finnish Gulf hosting sea water with very low salinity and the lower reservoir being a cavern in depth of -550m in the granite body. “It consists of an underground reservoir in crystal underground rock, chafers connecting it to the ground and to the seabed, and other land-based objects,” the company explained.

The commissioning of the facility is scheduled for 2029. The project originally received funding of €650 million, as an EU Project of Common Interest.