A reversible-flow hydroelectric power station located in the municipal area of Capdella in the Catalonian Pyrenees; the first pure pumped station to be installed in Catalonia. Its total output is 415,000 kW, with a flow of 125 m³/s and a head of 400 m.
The power station sits in a cavern excavated in granite slate transition terrain, measuring 80 x 40 x 20 m.
It took four years to build (1981-1985) for a total cost of 46,440 million euros.
The main works carried out were:
-Penstocks: The excavation of two tunnels in granite, with a total length of 1,143 m, gradient of 104.63% and excavation diameter of 4.20 m
-Subterranean power station: Excavated using the “new Austrian method” procedure
-Discharge tunnels: Four tunnels dug into the rock with a total length of 740 m
-Intake works: Four reinforced concrete intake units with portals 5.50 x 5 m, grilles and gates
-Cable tunnels: Four tunnels through rock, with a length of 460 m, gradient of 72.98% and average cross-section of 12.26 m²
-Receiving station: Constructed in reinforced concrete on the mountainside, with a footprint of 2000 m², average height of 24 m and an avalanche-resistant roof
-Access, drainage, test and aeration tunnels: These have an excavated volume in the rock of 60,000 m³ and a total length of 3,500 m
-Site access road: Length 8,325 m, featuring a tunnel 190 m long and two bridges with decks of post-tensioned girders on piles.
-Penstocks: assembly and welding