The Connecting Europe Facility for Energy (CEF Energy) is supporting the studies with a grant of more than 2.1 million euros for the modernisation of the Čierny Váh pumped hydro energy storage plant in Slovakia. The modernisation of Slovenské elektrárne’s plant is a Project of Common Interest (PCI).
Over the next 24 months, the studies will prepare the ground to upgrade two of the plant’s six units to variable-speed turbines, improving operational efficiency, while also designing a hybridisation system to optimise the integration of a large-scale battery energy storage system (BESS) of up to 80 MW/160 MWh.
Driving innovation in hybrid storage
The development is among the first in Europe to combine traditional pumped hydro storage with batteries on such a scale. The studies will define the technical specifications, including market simulations, financial gap assessments and detailed designs for hydro, electro-mechanical, civil engineering and digital control systems.
The project will provide valuable lessons for the wider European energy system and could allow a significant amount of balancing energy to be exchanged across borders, for example with Hungary, Poland and Czechia.