Isollaz Power Plant
The Isollaz power plant, located in the municipality of Challand-Saint-Victor, is a reservoir hydroelectric plant and performs variable load production between full load with 83 m/s and standstill. It was built in 1928, designed by the architect Giovanni Muzio from Milan. The power plant houses two Pelton turbines with a total capacity of 32 MW.
From the Isollaz power plant reservoir starts the 7-kilometre-long open-channel flow diversion channel, which is almost completely made up of a rock tunnel. Along its course, thanks to a pressure pipe, water from the Graines stream is collected and then transformed into hydropower.
To obtain the concession for the plant it was required to build a demodulation basin on the outlet. The reason for the obligation was not to penalize the existing Verrès power plant located downstream, which had a maximum flow rate of 43 m/s.
After the Verrès plant was upgraded, the demodulation basin was demolished and the land adapted to its surroundings.
This plant is part of one of the Energy Tours routes.
Characteristics of the plant
Key information
Municipality: Challand-Saint-Victor (AO)
Commissioning: year 1928
Watercourse: Evançon stream
Intake structure: Brusson Basin
Other information
Altitude: 671 m asl
Catchment basin: 177 km2
Capacity: 200,000 m3
Diversion canal: open-channel flow
Length: 7 km
Other information
Units: no. 2 with Pelton turbine
Concession jump: 601 m
Flow rate: 8.2 m3/s
Power: 32 MW