Coo
Coo pumped hydro overview.
Coo is a pumped-storage hydroelectric station in the Belgian Ardennes. It stores electricity by pumping water from a lower reservoir into upper basins and releases it through turbines when needed. Its extension programme includes reservoir works and upgrades to three generating units.In OperationBelgium
At a Glance
Declared capacity
1,159 MWEnergy storage
6,450 MWhOperator
Data coming soonCountry
BelgiumLocation
50.372°, 5.870°Website
Official project pageOwnership
1 record| Share | Organisation | Role | Details | Period |
|---|---|---|---|---|
| Unknown |  | Owner Operator | ENGIE Electrabel owns and operates the Coo pumped-storage station. | Current / not dated |
Organisations
7 recordsOrganisations recorded as working on this asset or its project, and their role.
| Organisation | Role | Details |
|---|---|---|
| Pumped-storage owner and operatorOwner Operator | ENGIE Electrabel operates the Coo pumped-storage station and commissioned the generating-unit upgrade programme. | |
| Reservoir extension civil works contractorEpc Balance Of Plant | eloy and Jan De Nul formed the joint venture carrying out the Coo reservoir extension civil works. | |
| Owning energy group and extension sponsorDevelopment And Operation | ENGIE presents the Coo pumped-storage station and its extension programme within its Belgian generation portfolio. | |
| Evacuation substation upgrade contractorSubstation Electrical | GE Grid Solutions was awarded the turnkey upgrade of key equipment in the Coo evacuation substation in April 2021. | |
| Reservoir extension civil works partnerEpc Balance Of Plant | Jan De Nul partnered with eloy on the Coo reservoir extension civil works. | |
| Reservoir extension engineering consultantEngineering And Design | Tractebel was the engineering consultant for the Coo reservoir extension described by the civil works contractor. | |
| Coo I generating-unit upgrade contractorEquipment Supply | Voith Hydro was commissioned in 2021 to upgrade three Coo I power units, following its earlier automation work on all six units. |
Supplier registration
Contact page onlyHow suppliers get onto this project's radar: its standing register, supplier portal or contact route.
Enquiries can use the general contact route published for the station’s extension programme. Supplier purchasing terms are available through the operator’s Belgian website.
The Coo extension page provides a general project enquiry route. Supplier’s Place publishes Belgian purchasing terms and support for existing suppliers; it does not constitute an open Coo supplier register.
SourceChecked 28 Oct 2026
Capacity history
Recorded project capacity figures. Future-dated changes are shown but are not used as current capacity.
| Effective | Capacity type | Capacity | Source |
|---|---|---|---|
| Current | Declared capacity | 1,159 MW | ENGIE: proposed expanded station power announced in May 2021 |