Czech ČEZ invested over CZK 5 billion in hydropower plants, major project awaits Orlík

Energy company ČEZ has so far modernised 20 hydropower plants with more than 40 generating units. According to the company, the plants are five to ten percent more efficient after modernisation and require less water. Total investment since 2007 has exceeded CZK 5 billion. Further modernisations are being prepared, the largest of which will be the conversion of the Orlík plant into a pumped-storage plant for around CZK 8 billion. ČEZ informed ČTK of this today. ČEZ's hydropower plants supplied around 1.8 terawatt-hours (TWh) of electricity to the grid last year, covering the consumption of more than half a million households.

ČEZ began modernising its hydropower plants in 2007. The work covers all types of hydropower plants – from large reservoir plants and pumped-storage facilities to small run-of-river plants. It has already been completed, for example, at the Dlouhé stráně, Lipno, Slapy, Kamýk and Vrané nad Vltavou plants, as well as at smaller facilities at the Brno reservoir, in Hradec Králové, Les Království and Pardubice. The combined capacity of the generating units exceeds 1500 megawatts (MW), equivalent to around three-quarters of the capacity of the Dukovany or Temelín nuclear power plants. The upgrades increased the efficiency of large plants by up to five percent and of small hydropower plants by up to ten percent.

According to the company, the facilities need to be adapted both to changes in the operation of the entire sector and to changing hydrological conditions in nature, such as drought and the associated lower river levels.

"Hydropower plants are important for the energy system because they can ramp up to full output within tens of seconds and help stabilise the grid. Our response to increased reliability and security requirements is the modernisation of all types of plants, in which we have invested more than CZK 5 billion in recent years. This has extended their service life and made it possible to increase efficiency and maintain operation even at flow rates and water levels at which they would previously have had to be shut down," said Pavel Šleška, director of ČEZ's conventional energy division.

According to him, the company applies scientific and technical knowledge in the design of the mechanical and electrical parts of generating units during modernisation, for example in turbine runner geometry and control systems. The work also includes the replacement or repair of the plant's main mechanical and technological components, such as turbine runners, generators and control systems.

"Repairs are currently under way at the small Kořensko and Lipno II hydropower plants on the Vltava, but the main work is still ahead of us. A major modernisation of the largest Vltava plant at Orlík is getting under way, and we want to convert half of it into a pumped-storage plant capable of storing large volumes of electricity for later use. In the coming years, the pumped-storage Dalešice plant, the Vltava's Štěchovice plant and Střekov on the Elbe will also have fully modernised generating units," said Róbert Heczko, director of ČEZ's hydropower plants, outlining the company's further plans.