A renewable, storable energy

Hydroelectric power plants produce electricity using water channelled through dams. The water activates turbines according to a flow rate that is regulated by a valve. Each turbine drives an alternator that converts the mechanical energy of the water to electricity.

Hydraulic energy has one major advantage: it can be stored and then brought on stream in just a few minutes. It is also a competitive form of energy, due to the long useful life and low cost of hydroelectric plants.

There are two different types of hydroelectric plants:

  • run-of-the-river power plants which use the continuous flow of the water and provide a constant supply of basic energy
  • pumped storage power plants which store the water in a reservoir, creating a guaranteed supply of energy available when needed during peak consumption periods

Marèges factory, Liginiac

The efficiency and mutual enhancement of GDF SUEZ’s subsidiaries

GDF SUEZ is a major player in hydroelectric power through the expertise of its subsidiaries.

  • Compagnie Nationale du Rhône (CNR), the second largest producer of electricity in France, develops and operates the river system and has three missions: electricity production, navigation and irrigation.


  • Tractebel Engineering, one of the leading European engineering firms and world leader in the area of dams, has been involved in the development of 30,000 MW hydroelectric plants.
  • Coyne et Bellier, a Tractebel Engineering subsidiary, is an engineering firm working in the area of major water, energy, transport and building infrastructures. The firm owns the largest number of references in major international hydraulic and hydro-electric dams.


  • Société Hydro Electrique du Midi (SHEM), is a leading player in the Great South West region of France, with a hundred years of experience in hydroelectric power. Its assets generate average annual output of 1,836 GWh, equal to the annual consumption of 1.2 million residents.

Over 700 dam engineering references worldwide


Hydraulic energy is the second largest source of electricity production in France.

GDF SUEZ produces 25% of the country’s hydroelectricity; it helps promote this renewable energy and is jointly involved in developing the territories for the benefit of local residents, in partnership with the local authorities and economic players.

Invitation to tender for hydroelectric concessions

France has nearly 400 hydroelectric concessions which account for over 95% of the installed power. Some of these concessions have come to an end and therefore need to be renewed and are being put out for competitive tender.

The key figures for this renewal by 2015:

  • 49 projects put out to tender,
  • 10 concessions renewed with total power of 5,300 MW,
  • 20% of the hydroelectric assets in France concerned, out of a total 25,300 MW.


GDF SUEZ is Brazil’s leading independent producer of electricity, operating 21 power stations, including 13 hydroelectric plants. These major sites are accompanied by initiatives and projects conducted in close cooperation with local associations and organizations.

  • The new Estreito hydroelectric plant was inaugurated in October 2012. With an installed capacity of 1,087 MW, it produces enough energy to supply four million residents.
  • The run-of-the-river Jirau dam, part of the Madeira river complex, has a 3,450 MW capacity. It will enable Brazil to meet its growing demand for energy, while ensuring a secure supply. This dam, with an architectural structure that will limit its environmental impact, will reach commercial operation of its first units in early 2013.



Jirau project and its social and environmental programs

GDF SUEZ is the leading private electricity producer in Brazil, by operating 21 power plants, 13 hydroelectric ones. Through the project company Energia do B...


In September 2009, GDF SUEZ began construction of a run-of-the-river hydroelectric power plant in Chile, on the lower section of the Laja River. A system of turbines installed at the foot of the dam avoids the need to divert the river and minimizes the dam's environmental impact. It's a one-of-a-kind project in Chile, which will save the equivalent of nearly 29,000 tons of oil.

The power plant, with its 34.4 MW capacity, is scheduled to become commercially operational in September 2013.

The United States

Through its subsidiary FirstLight Power Resources, the Group operates hydroelectric power plants on the Shetucket and Housatonic rivers in Connecticut and Massachusetts. These stations, which operate during periods of high electricity demand, play an important role in the conservation effort to protect marine wildlife thanks to the fish ladders installed in navigable waterways

GDF SUEZ also operates a 1,080 megawatt pump turbine plant in Northfield, Massachusetts and a 7 MW hydroelectric power plant in Winooski, Vermont..


Electrabel, a Group subsidiary in Belgium, operates the Coo-Trois-Ponts pumped storage hydroelectric plant. It is located in the Ardennes region near to the Coo waterfall and has an installed power of 1,164 MW.

The United Kingdom

First Hydro Company, a subsidiary of GDF SUEZ Energy International, is one of the most dynamic electricity producers in the United Kingdom with a 2,088 MW installed capacity. It manages and operates the pumped storage plants in Dinorwig and Festiniog, Snowdonia (Wales).


GDF SUEZ International also operates two hydro plants in Spain, Electrometalurgica del Ebro (36 MW) and Iberica de Energias (48 MW), and one in Laos, the Houay Ho Hydro plant (153 MW).

In pictures