Our dear guests from Lodz, Poland came to us on Thursday, 20thSeptember evening. Their team – 16 children and 4 teachers visitedmany places and sights in Czech Republic including our capitol Praguefew days before the visit of Radslavice. Friday 21st September morning we spent at our school together.During common morning activities came councilors of the Radslavicemunicipality headed by the mayor to greet us. We watched somepresentations, worked in workshops and did some sports at the schoolplayground. In the afternoon we organized a trip to the Hydroelectric PowerStation Dlouhé Stráně.
The Dlouhe Strane Hydroelectric Power Station is situated in Moravia, near Loucna nad Desnou in thedistrict of Sumperk. It prides itself with three superlatives: it has the largest reversing water turbine in Europe, 325 MW;it has the largest head of all power stations in the Czech Republic, 510.7 m; and it has the largest installed capacity inthe Czech Republic, 2 x 325 MW.The power station fulfils static, dynamic and compensatory functions within the power system. The static function liesin converting the surplus energy in the system into peak-load energy - at periods of surplus electricity in the system,namely at night, water is pumped from the lower to the elevated storage reservoir; and during the on-peak periods,when there is a shortage of electricity, the power station’s turbines generate electricity. The dynamic function of thehydroelectric power station means functioning as the system’s output reserve, generating the regulating output andenergy, and participating in the frequency regulation of the system. The compensatory operation facilitates the voltageregulation within the power system.Construction on the power station began in May 1978. But in the early 1980’s, the central bodies decided to hold up theproject. In 1985, the design was modernized, and after 1989, it was decided to complete the project. The power stationwas designed as an underground hydroelectric power station. Both turbine sets are located under the ground, in a 87.5m x 25.5 m x 50 m cavern. Next to the turbine chamber, there is located a 115 m x 16 m x 21.7 m transformer chamber. Itincludes two unit three-phase transformers, 22 kV switching rooms and other equipment.The elevated storage reservoir is connected with the underground power station by two penstocks, 1,547 m and 1,499m long, each feeding one turbine set. Two discharge tunnels, 5.2 m in diameter, connect the station with the lowerreservoir. The tunnels are 354 m and 390 m long. The lower reservoir is on the Divoká Desná River. Its total capacity is3.4 million m3 of water; it has a 56 m high dam, and its water level fluctuates by 22.2 m. The elevated reservoir issituated on top of the Dlouhé Stráně mountain, 1,350 m above sea level. Its total capacity is 2.72 million m3.The station is equipped with two reversing turbine sets, each rated at 325 MW. The reversing turbine’s output is 312 MWin the storage pumping operation, and up to 325 MW in the turbine operation.The administration building and the control room are situated on the surface, along with the outgoing lines with a 400kV encased switching station, workshops and warehouses, garages, a sewage treatment station and a water treatmentstation.