EU funding anchors Slovakia's largest pumped-storage upgrade
The EU's Connecting Europe Facility (CEF) Energy is funding the first phase of the modernisation of the Čierny Váh pumped-storage hydropower plant in Slovakia, a project designed to convert part of the 735 MW facility to variable-speed operation. The SE Integrator project, led by Slovenské elektrárne, a.s., has secured €62.63 million in CEF Energy support. Works began at the end of July 2026 and the project is scheduled for completion in the third quarter of 2031.
Two of six units move to variable speed
Čierny Váh is Slovakia's largest pumped-storage facility, with an installed capacity of 735 MW across six existing pumped-storage units. The CEF-funded works modernise two of those six units, upgrading them from fixed-speed to variable-speed technology to give greater operational flexibility and improve performance and efficiency. The scope also includes upgrades to power delivery and control systems, the installation of frequency converters and associated civil engineering works.
€2.11m of preparatory studies, including batteries
Before construction began, €2.11 million in CEF Energy funding supported preparatory studies for SE Integrator. Those studies cover feasibility assessments, market simulations, financial gap analysis, civil engineering, hydro and electrical systems, battery energy storage, hybridisation and power-plant control systems. Their purpose is to define the technical specifications for integrating the different technologies. According to Slovenské elektrárne, the studies are progressing as planned.
Phase II: up to 80 MW / 160 MWh of battery storage
A second phase of SE Integrator is planned to complement the modernised pumped-storage units with a battery energy storage system of up to 80 MW and 160 MWh. That battery hybridisation component is not part of the CEF-funded Phase I works, but it forms part of the wider PCI 2.11 project. Together, the upgraded pumped-storage units and the proposed battery system would create a hybrid flexibility solution, combining large-scale pumped hydro with the rapid response capabilities of battery storage.
Flexibility with a regional footprint
Čierny Váh's significance extends beyond Slovakia's borders. The country is closely connected to neighbouring electricity markets, so additional flexibility at the plant can contribute to the stability of the wider Central European electricity system. CEF Energy frames the project as an example of how targeted EU investment modernises existing infrastructure while preparing electricity networks for the energy transition — ensuring sufficient flexibility to integrate more renewable generation while maintaining system security.
Source: CINEA / CEF Energy
This article was assisted by AI analysis. Please refer to the original source for official information.