During that time, 100 engineers and specialists from HYDRO Exploitation, under the supervision of a project manager, worked tirelessly to recommission this 1200 MW power station, holder of three world records:
- head (1883 m)
- power per Pelton turbine (3 x 423 MW)
- power per generator pole (35.7 MVA)
In parallel with the lining of the pressure shaft, carried out by CDC, HYDRO Exploitation specialists worked with two external engineers, as well as suppliers (Andritz, Alstom, ABB, …) for commissioning. The main steps were :
- maintenance and updating of the installations until the end of 2008
- preliminary testing from the beginning until the summer of 2009
- wet commissioning of the headwater gallery and well at the end of August 2009
- commissioning of the three units with a 15 day interval, and during an intermediary phase with the parallel commissioning of two groups
- parallel running of the three groups with behavior testing of the new well from the 1st December 2009
The plant will be partly in production from the end of the year 2009 and completely from the end of January 2010. GEH Nendaz will be in charge of running this installation.
Ensuring the recommissioning of an almost new plant (2 years of running time) after nine years of shut down is a first! During that period of time, HYDRO Exploitation had put measures in place to ensure optimal conservation of the machines.