Nant de Drance Hydropower Plant

Nant de Drance
Lac d'Emosson forms the lower reservoir
CountrySwitzerland
LocationFinhaut, Saint-Maurice, Valais
Coordinates46°03′49″N 06°54′36″E / 46.06361°N 6.91000°E / 46.06361; 6.91000
StatusOperational
Construction beganSeptember 2008
Opening dateJuly 2022
Construction costUS$2.1 billion (CHF 1.9 billion, 1.5 billion)
Owner(s)Nant de Drance SA
Upper reservoir
CreatesLac du Vieux Emosson
Total capacity25,000,000 m3 (20,000 acre⋅ft)
Lower reservoir
CreatesLac d'Emosson
Total capacity227,000,000 m3 (184,000 acre⋅ft)
Power Station
Hydraulic head295 m (968 ft)
Pump-generators6 x 150 MW reversible Francis-type
Installed capacity900 MW
Annual generation2,500 GWh (est.)
20 GWh energy storage

The Nant de Drance Hydropower Plant is a pumped-storage power station in the canton of Valais in Switzerland. It is within the municipality of Finhaut, district of Saint-Maurice and about 14 km (8.7 mi) southwest of Martigny. Construction on the power plant began in 2008 and it began operations in 2022. It is owned by Nant de Drance SA, a consortium of Alpiq (39%), SBB (36%), Industrielle Werke Basel (15%) and Forces Motrices Valaisannes (FMV) (10%). The US$1.9 billion plant has an installed capacity of 900 MW and an energy storage capacity of 20 GWh.