The SE Integrator Project on the Čierny Váh River is among the first initiatives in Europe to combine a traditional pumped storage power plant (PSPP) with a modern battery storage on a large scale. The hybrid model will significantly increase the balancing capacity of the Slovak electrical grid and will also contribute to the stabilization of regional markets in Central Europe. The first phase of the Slovenské elektrárne project is being funded by the European Commission with a grant of € 62.63 million under the Connecting Europe Facility (CEF) programme. A total of € 650 million will be allocated to 14 cross-border energy projects.
“We are proud that Slovakia will have one of the most technologically advanced pumped storage power plants in Europe. The introduction of variable speed and the largest frequency converters of their kind in pumped storage power engineering is a breakthrough that will take our flexibility to an entirely new level. We have demonstrated that even a country of our size can deliver projects of European significance.”
Branislav Strýček, Chairman of the Board of the Board of Directors and CEO of Slovenské elektrárne, a.s.
The Čierny Váh power plant is the largest pumped storage power plant in Slovakia with an installed capacity of 735 MW and an annual generation of approximately 200 GWh. Its hybridization will significantly expand its functions:
“A strong and independent Energy Union, which brings clean and cheap energy to consumers, must be based on an integrated and secure energy infrastructure. The projects we financially support will strengthen Europe's competitiveness and energy security and put us on a stable path to independence.”
Dan Jörgensen, European Commissioner for Energy
The growing share of wind and solar power in Europe significantly increases the need for long-term electricity storage and its balancing. Pumped storage plants provide nowadays more than 90% of all large-scale storage in the EU and are the pillar of grid stability. Hydropower is still the largest low-carbon power source in the EU. Slovenské elektrárne company operates 31 hydroelectric power plants with an installed capacity of 1,653 MW, out of which 916.4 MW are pumped storage power sources (Čierny Váh, Liptovská Mara, Ružín, Dobšiná). Hydropower sources account for an average of 11% of SE’s annual electricity generation of and are among the fastest deployable balancing capacities in the country.
The hybrid regime of Čierny Váh will enable Slovakia to provide primary, secondary and tertiary balancing from a single source, thanks to a unique combination of pumped storage technology and battery storage, capable of responding almost instantly to fluctuations in generation from renewables. At the same time, it will create some space for cross-border trading of balancing energy on the European MARI and PICASSO platforms. This will increase Slovakia's integration into the single market with ancillary services. Thanks to significantly expanded balancing capabilities, the modernized Čierny Váh will be able to support grid stability of the neighbouring countries - Hungary, Poland and the Czech Republic - and, if necessary, Ukraine, making it one of the key elements of regional energy security.
Having more than 60% share in the overall electricity production in Slovakia, Slovenské elektrárne, a.s. is the largest electricity producer in the country. After having shut down the last coal power plant in 2024, it generates all electricity without direct CO2 emissions. It operates 5 nuclear units, 31 hydro power plants, and 2 photovoltaic plants.
The Company´s commitment to generate electricity from low carbon sources makes it the leader in sustainable energy generation in the Central and Eastern Europe. The Company was listed four times in the prestigious index Europe's Climate Leaders, developed by The Financial Times and Statista since 2021.
Slovenské elektrárne, a.s. has two shareholders. The majority shareholder, with 66% share, is Slovak Power Holding B.V. (SPH) owned by a Czech energy group Energetický a průmyslový holding (EPH). The second shareholder is the Slovak Republic holding 34% of the company.
