ČEZ to Build Czech Republic’s Fourth Large Pumped-Storage Hydropower Plant

With a globally unique modernisation project, ČEZ plans to transform the Orlík hydropower plant into the Czech Republic’s fourth large pumped-storage hydropower plant by 2033. The facility will be capable of storing enough electricity to cover the daily consumption of around 80,000 households.

The Czech Republic is set to gain a fourth large pumped-storage hydropower plant by 2033. Energy company ČEZ plans to comprehensively modernise the Orlík hydropower plant, located around 60 kilometres south of Prague, and partially convert it into a pumped-storage facility. Alongside the plants at Dlouhé Stráně, Dalešice and Štěchovice, the Orlík reservoir will also be used to store electrical energy in the form of water.

As part of the project, two of the plant’s four turbine units will be equipped with new technology enabling bidirectional operation. In future, water will be pumped back from the lower-lying Kamýk reservoir to the higher-lying Orlík reservoir. This will make it possible to store surplus electricity and feed it back into the grid when required.

Foto: ČEZ

According to ČEZ, the facility will achieve a storage capacity of up to 750 megawatt hours. This corresponds to the daily electricity consumption of around 80,000 Czech households. The conversion is also considered exceptional from a technical perspective: both the transformation of an existing large hydropower plant into a pumped-storage facility and the replacement of Kaplan turbines with reversible Francis turbines are regarded as globally unique solutions.

The Orlík hydropower plant was commissioned 63 years ago and is a central part of the Vltava Cascade system. Following the planned modernisation, the facility will not only generate electricity but also serve as a large-scale energy storage system. The height difference of around 70 metres between the Kamýk and Orlík reservoirs enables efficient pumping operations.

Plant Operations to Be Largely Maintained During Construction Works

One advantage of the project is that no additional land will be required. The new pumped-storage function will be implemented within the existing infrastructure. At the same time, plant operations are expected to be largely maintained throughout the construction works. According to ČEZ, at least two of the four turbine units will remain in operation at all times during the phased modernisation process.

Foto: ČEZ

The actual conversion works are scheduled to begin in 2027. All four generating units will be modernised by 2033. The plant’s total capacity will remain at 364 megawatts. Two turbines with an output of 95 megawatts each will continue operating in conventional mode, while two new reversible turbines with an output of 87 megawatts each will be designated for pumped-storage operation.

The project is expected to increase the storage capacity of Czech pumped-storage hydropower plants by more than twelve per cent. At the same time, the modernised facility is expected to improve grid stability and facilitate the integration of renewable energy sources.