Expanding and modernising the hydroelectric fleet

EDF wants to increase the performance of its existing power plants by investing heavily in their modernisation. It has defined an industrial plan designed to boost their capacity and improve operating quality. The Group is also continuing its capacity expansion projects in France and other countries.

Boosting capacity and availability

EDF is constantly modernising the hydroelectric fleet for which it holds the concession by replacing or expanding – i.e. adding further – turbines. All projects have the same purpose: to increase the efficiency and availability of the sites.

Launched in 2011, the Romanche-Gavet project near Grenoble is the largest hydro expansion project in France. It will replace six power plants and five dams with a single underground run-of-river plant, which will operate without a reservoir.

Romanche-Gavet, La Bâthie and La Rance are examples of EDF projects designed to improve its hydroelectric assets, which make up Europe’s largest hydropower fleet.

At Romanch-Gavet, two 47 MW generating sets are being installed to raise output at the site to 560 GWh a year. The 155 GWh gain is the equivalent of the consumption of a city with a population of 60,000. The project is also designed to comply with sustainable development principles, including upgrade of the existing buildings and the local ecosystem. The International Hydropower Association has given Romanche-Gavet a “very high performance” sustainability score.

Improving hydro operations to guarantee security of supply

Upgrading industrial assets also includes improvement of operation and monitoring methods to meet abrupt fluctuations in electricity demand.

In the Savoie department, the three dams at the La Bâthie complex store more than 200 million cubic metres of water. The complex is a strategic facility helping to ensure stable power supply for the whole of France. EDF invested €50 million to raise the power plant’s capacity to 600 MW by increasing each of the six generating sets from 92 MW to 100 MW. A 48,000 cubic metre buffer reservoir was also built. It captures the water discharged at high speed from the power plant and will limit high water in the Isère River. La Bâthie will therefore be able to start up very quickly if necessary without danger to river users.

The most recent major hydropower investment project is designed to keep the La Rance tidal power plant in Brittany operating at the highest efficiency level. The plant has been generating electricity from tidal energy for 50 years. The La Rance Project is a 10-year EDF investment programme at the site, which includes:

• renovation of the 24 bulb turbines, the gates and the automatic control systems (gantry cranes, lifts)
• replacement of the extra high voltage (245 kV) outgoing transmission cables.

The objective is to ensure the long-term generation of clean, predictable and renewable power over coming decades. The La Rance tidal plant will continue to generate electricity while work is carried out.