The Signayes hydroelectric power plant is the run-of-river type: therefore, it does not have its own storage of water to be used at different times than in natural times.

Located upstream from the city of Aosta, it uses water power from the catchment area of the Great St. Bernard Valley and Valpelline. The Signayes engine room is in a cavern at the bottom of a 120 m deep shaft. The outlet channel empties into the reservoir of the Buthier stream intake, and is then fed into the diversion channel of the Quart plant. Medium-voltage busbars go up along the shaft to the power station located outside. The total capacity of the installed turbines is 42 MW, and its average annual hydropower production reaches 220 GWh: therefore, the plant plays a key role even in the winter period.

The Entrebin basin of the Signayes plant is fed by an 11-km open-channel flow to collect water from the Buthier stream intake, the Valpelline power plant outlet, and the Ollomont and Artanavaz intakes. The canal meanders, following contour lines, through fields and fruit orchards that cover the slopes of the area, finally crossing the Artanavaz stream with a dizzying canal bridge.

Starting in 2020, the plant has undergone upgrading works totalling about 6 million Euro, which involved mechanical, electrical, automation and control parts.
 

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