Société Electrique de l’Our S.A., an incorporated company under Luxembourg law, operates the pumped-storage power plant (PSP) in Vianden, run-of-river hydroelectric stations on the Moselle and Our rivers as well as windfarms in Luxembourg. The main shareholders are the Grand Duchy of Luxembourg and RWE Power, each holding 40.3%. By contractual arrangement, use of Vianden pumped-storage power station is the preserve of RWE Power. The RWE power plant portfolio can thus avail of up to 1,296 MW of turbine capacity. 

The Vianden pumped-storage power plant comprises a cavern power plant (machines 1-9), a shaft power plant (machine 10) and a separate cavern for machine 11.