Survey of Energy Resources 2007
Tidal Country Notes
Relatively few tidal power plants have been constructed in the modern era. Of these, the first and largest is the 240 MW barrage on the Rance estuary in northern Brittany. The 0.8 km long dam also serves as a highway bridge linking St. Malo and Dinard. The barrage was built as a full-scale demonstration scheme between 1961 and 1966 and has now completed 40 years of successful commercial operation. Annual generation is some 640 million kWh.
Originally the barrage was designed to generate on both flood and ebb tides; however, this mode of operation proved to be only partially successful. The barrage is now operated almost exclusively on ebb tides, although two-way generation is periodically instigated at high spring tides.
In 1988 the plant became fully automated, requiring the integration of complex operational cycles imposed by variable heads, and the necessity for continuous regulation of the turbines to optimise energy conversion. A 10 year programme for refurbishing its 24 turbines was begun in 1996, on the plant's 30th anniversary.
Despite its successful operation, no further tidal energy plants are planned for France, which is now dominated by generation from nuclear stations.