Water: a source of electricity
ENGIE Electrabel operates 3 types of power plants that run on water:
- Pumped-storage power stations (Coo)
- Small run-of-river and dam hydroelectric power plants
Discover more about our hydroelectric power stations in our brochure on the Coo pumped storage plant (in French).
Watch the video about Coo and the small hydroelectric plants.
Coo pumped storage power station
The tree bassinsVirtual tour of the Coo power station
Works at the generatorDiscover more about the Coo power station in our brochure
A flexible and large-scale storage solution
For over 40 years (since 1972), the Coo power station has played a core role in our energy mix. It is vital to covering the growing need for flexibility triggered by the energy transition and the intermittent renewable energies. Coo’s maximum capacity totals 1,164 MW.
Pumped storage is currently the only way to store electricity on a large scale. In Belgium, the Coo station is therefore essential for the balance on the grid. The turbines can be started up at any time to offset a sudden drop in generation or to absorb excess electricity. As such, when demand is too low Coo stores the power generated elsewhere to restore it during peak consumption times.
A clean and beneficial technology
- Easy to modulate the power generated according to fluctuations in demand
- Practically instant energy reserves in the event of a disruption on the grid
- Can be launched quickly (in just a few tens of seconds)
- Balances unplanned renewable generation (wind power, solar power)
- Clean source of energy that does not consume water or require combustion
- Limited impact on the environment owing to the fact that most technical facilities are located underground
Did you know: when running at full capacity, the Coo power station can provide 1,164 MW for six hours, as much as a nuclear unit but with a start-up time of under two minutes.
How does Coo pumped-storage station work?
- The flowing water turns a turbine which then turns a The generator transforms the turbine’s mechanical energy into electricity. Coo’s units are reversible and can function as turbines or pumps.
- During times of low demand for electricity, the water is pumped to the upper reservoirs.
- During peak periods, the water is then poured into the lower reservoir via the machine room housing the turbines and generators that generate the electricity. The equivalent of 10 Olympic swimming pools can flow through here per minute! The overall yield of the power station is 75%, meaning that 75% of energy extracted during off-peak hours is restored during peak hours.
The small hydroelectric power stations
Engine room of the Bévercé hydroelectric power stationDiscover more about our hydroelectric power stations in our brochure (in French)
Bütgenbach dam power stationENGIE is a major player in hydroelectric power around the world
Penstock between the hydroelectric dam Robertville and the power station BévercéDiscover the Marèges dam power station operated by SHEM (subsidiary of ENGIE)
Run-of-river or dam power plants
Electrabel operates 10 run-of-river and dam power plants in the south-east of Belgium, primarily along the Warche and Amblève. These plants have a total capacity of 22 MW.
How does a dam hydroelectric power plant work?
- A run-of-river power plant is located on a dammed water course. There is a low drop height (between 3 and 15 metres). The volume and speed of the water flowing through the turbines depends on the flow of the river.
- A dam power plant first storages a huge quantity of water in an artificial barrier lake. The turbine is located either close to the foot of the dam or further downstream.
Did you know: in addition to generating electricity, a dam/barrier lake can also be used as a reservoir as well as to regulate the reserves of drinking water and rises in water levels.