Energiasalv is a large scale energy storage project in Paldiski situated northwest Estonia. It uses the Zero Terrain technology - a geotechnical pumped hydro storage solution that allows to store energy in places where it has not been possible before. Unlike conventional pumping stations worldwide Energiasalv uses the height difference that occurs between surface water bodies and caverns built into the Earth’ crust. The project has a unique hybrid business model of combining power storage services and deep granite mining which remarkably improves financial viability because of multiple revenue sources. The plant is planned to become operational near Tallinn in Estonia in year 2028 and it will offer flexibility services to the Nord Pool Spot power market.