Ecosystem-friendly hydropower, high up in the Alps
A small hydroelectric power plant that came online this year in the French Alps had an important point to prove: sophisticated renewable energy systems can be built in harmony with delicate mountain ecosystems.
Actemium is proud to have played an integral part in the construction of the new hydroelectric power plant on the Sarenne River, a project set in motion in 2021 by the Compagnie Nationale du Rhône (CNR), a French company operating dams and power plants along the Rhône River to provide clean energy and support environmental protection.
Water + gravity = power
The “high-head” facility, built to take advantage of a 735-meter altitude drop, is designed to supply renewable electricity equivalent to the power consumption of 16,000 residents.
A natural waterfall, the Sarenne cascade, enables a maximum turbine flow rate of 1.8 m3/s, and the plant has an installed capacity of 11 MW spread across two production units.
Preserving a delicate mountain environment
The project paid particular attention to respecting biodiversity and taking into account the sensitive mountain environment. It stems from CNR’s strategy to develop hydroelectric activities beyond the Rhône River and is an important component of the Isère region’s accelerating energy transition.
One of the project’s main objectives was striking the proper balance between economic value, respect for biodiversity and the sensitive mountain environment. Measures put in place to preserve the environment and biodiversity throughout the duration of the work included the construction of a fish bypass, and the restoration and revegetation of all construction sites.
Actemium puts the pieces into place
Actemium Grenoble has well-established expertise in the small hydroelectric power plant (SHP) market, making the company a natural winner of the contract to design and build the electromechanical equipment for this plant in 2020.
Actemium Grenoble carried out all the design and sizing studies for the equipment between the water intake at 1,456 meters above sea level and the Enedis network, including:
- Two 5.5 MW Pelton turbines (ATB Riva Calzoni)
- Two alternators (Leroy Somer)
- 1 C13-100 and C13-200 high-voltage substation (Siemens)
- 1 7.2MVA 20kV/6kV power transfer transformer (ABB)
- 1 450A charger/battery and 1 4.5 KVA inverter (ENAG)
- 1 30-ton overhead crane with a 12-meter span (FAYAT)
- 1 building ventilation and air conditioning system (FIDEC)
- 1 M580 automation control system (Schneider) for the generators and general services
The installation work took 12 months and was spread across three villages in Isère:
- Huez (altitude 1,456 m), where the water intake is located
- La Garde-en-Oisans, home to a 3,660-meter underground waterway and an equipment storage site on a platform at 1,000 meters of altitude
- Bourg D’Oisans (altitude 721 m), where the power plant is located
The power plant is now operational.