EDF, hydroelectricity supplier: one-of-a-kind expertise serving innovative projects

EDF has been designing, building and operating one of Europe’s largest hydroelectric fleets for the past 70 years. During this time it has acquired project design and management capabilities that have resulted in contracts throughout the world. The Group builds on its expertise to develop new ways to tap the kinetic energy in water flow, such as marine energy.

EDF’s hydro engineers: technical and environmental expertise

EDF’s two hydroelectric engineering units cover the entire generation chain:

• upstream, the Hydro Engineering Centre (CIH) provides consultancy services at all stages of project development, from feasibility studies to construction and refurbishment;
• downstream, the General Engineering Division (DTG) provides the full range of services for operation, from facility monitoring to hydro-meteorological forecasting.

To control the impact of its facilities on water quality, plants and animals, EDF set up the National Hydraulic and Environment Laboratory (LNHE). It employs about a hundred specialists in hydrology, sedimentology, river pollution and aquatic life. Their job is to assess the environmental aspects of a project as it is developed and to define offsets and/or support measures.
This comprehensive expertise applies to projects that explain why French hydro facilities are among the European leaders:

• Romanche-Gavet, in the south-eastern Isère department, where six power plants are currently being replaced by a single underground plant that will generate 30% more electricity than the six combined
• La Coche, in the south-eastern Savoie department, where a 240 MW generator set will be built alongside the four 80 MW existing generator sets to boost the power plant’s availability and capacity.

EDF also signs some 50 contracts outside France every year. The contract to build the Sinop dam in Brazil, signed in 2014, is an example. Some projects, such as the construction and operation of the Nam Theun hydroelectric plant in Laos, have become benchmarks. Commissioned in 2010, the project includes South-East Asia’s largest dam and a 1,079 MW power plant. Some 95% of the electricity generated is exported to Thailand and the remaining 5% covers 20% of the annual electricity consumption in Laos.

Fostering the emergence of new technologies

To meet growing energy demand and limit the greenhouse gas effect, EDF’s Hydropower Engineering and Generation Division (DPIH) is developing new renewable marine energy technologies. The most ambitious project is the world’s first tidal farm, set up in 2015 in Paimpol-Bréhat off the coast of northern Brittany.

The project, launched in 2008, involves developing “tidal turbines”: huge 16 metre diameter, 850 tonne submerged wheels connected to an offshore converter. These turbines use the energy of marine currents to generate electricity, which is fed into the grid via a 15 km submarine cable.

Paimpol-Bréhat is part of the effort to develop an ocean-based renewable power generation industry. Research is under way to exploit other sources of energy in the sea, including wave energy, thermal energy derived from the temperature difference between surface and deep water, and osmotic energy from contact between saltwater and freshwater in estuaries and marine biomass.

Innovation in hydroelectric generation also involves existing plants. To strengthen the safety of dams at risk of sudden flooding of the “thousand-year flood” category, EDF engineers have invented a flood control system shaped like the keys of a piano. The device increases the length of the spillway over which the water will flow. The Malarce dam in the southern French Ardèche department, one of six dams to be fitted with the system, can now release up to 4,600 cubic metres per second of water compared with 4,000 previously.

This drive for technological leadership is also reflected in recruitment and the emergence of new job profiles.