The Nant de Drance power plant has a capacity of 900 MW, making it one of the most powerful pumped storage plants in Europe. The power station is located 600 metres underground, between the Emosson and Vieux Emosson reservoirs, and once it's fully operational, it will be able to generate close to 2.5 billion KWh a year. The plant offers flexible power generation, playing a key role in stabilising the electricity grid throughout Europe and in safeguarding Switzerland’s power supply.
900
MWthe capacity of the Nant de Drance plant, which is equivalent to that of the Gösgen nuclear power plant
6
the number of Francis turbines, each with a capacity of 150 MW
2,5
billion kWhthe plant's annual production, which is equivalent to the electricity demand of the Swiss national rail service (SBB/CFF)
No. 2
Emosson Lake is currently the second-largest reservoir in Switzerland, after Grande Dixence, and its 180-metre-high dam is the country’s fifth tallest
Less than
the time needed for the power plant to stop pumping at full speed and start turning the turbines at full speed; and less than 10 minutes to switch from turbine mode to pump mode.
5
minutesthe time needed for the power plant to stop pumping at full speed and start turning the turbines at full speed; and less than 10 minutes to switch from turbine mode to pump mode.
More than
the plant's yield, which is currently one of the highest for a pumped storage power plant
80%
the plant's yield, which is currently one of the highest for a pumped storage power plant
25
million m3the capacity of the Vieux Emosson, which is more than 6,500 Olympic-sized swimming pools
2
countriesthe water in the Emosson reservoir comes from both Switzerland and France
425
mthe height of the two vertical penstocks that connect the Vieux Emosson and Emosson reservoirs – that's 100 m higher than the Eiffel Tower (324 m)
7
mthe diameter of the two penstocks
194
mthe length of the underground turbine chamber, which is equivalent to two football fields
20
hoursthe time needed to empty out the Vieux Emosson reservoir, which would generate 18 GWh of electricity
17
kmthe total length of the underground galleries within the Nant de Drance plant