According to Peep Siitam, an important milestone has been reached in the realisation of the project. “I am pleased that the environmental impact assessment report of the project has been declared compliant and we are on schedule. The next stage is applying for a building permit, which we want to achieve this year, hopefully already during the coming months,” Siitam said.

Energiasalv is planning a PHES in Paldiski. It consists of an underground reservoir (depth orientated at 500 to 600 m) in crystal underground rock, chafers connecting it to the ground and to the seabed, and other land-based objects (control centre, substation, etc.). The operation of the plant consists in exploiting the potential energy generated by the difference between the sea level and the altitudes of the underground reservoir. Electricity is consumed when water is pumped from the lower reservoir to the upper reservoir, i.e. when there is a surplus capacity in the electricity system or when the price of electricity is cheap. Electricity is produced by passing water from the upper reservoir through the lower reservoir of turbines if there is a shortage of electricity production capacity in the system or if the price of electricity is high. Electricity turbines/pumps located in the relevant turbine hall at the bottom of the shaft which, according to operating mode, produce electricity (when water moves from the sea to the reservoir) or pump water back from the reservoir to the sea.

More info from the notice of statement:

https://www.ametlikudteadaanded.ee/eng/teadaanne?teate_number=1916341