The Maën Perrères hydroelectric power plant is located in the municipality of Valtournenche on the watercourse of the Marmore stream, 1,300 m above sea level, in one of the most popular tourist destinations in the Aosta Valley. The new plant, which replaces the previous one in service since 1928 but retains its essential features, was opened in the fall of 2002. 

The renovation work, in addition to the replacement of machinery and equipment, relocated the electrical part of power transformation and lines connecting with the transmission network, previously located inside the building, outside. The Perrères jump diversion works were only affected by the replacement of the penstock: the new one was installed on the site of the former Cignana jump penstock, allowing the production units to remain in service during the works. 

The Maën building houses the Cignana diversion, with a capacity of 22 MW, and the Marmore diversion with 25.2 MW. The Maën production area hosts a total of three hydropower generation units.

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