A geotechnical pumped-hydro energy storage plant is being constructed underwater on the Pakri Peninsula in Paldiski, Estonia. This location was chosen due to the favorable natural and geological conditions (sufficient sea depth, bedrock is amphibolite gneiss), its proximity to energy infrastructure, synergies with existing and planned industries, and the eco-friendly approach of the municipality. This pumped-hydro storage project will benefit from the unique characteristics of Paldiski, making it the best location for this endeavor.