The
Rance tidal power plant (
Usine marémotrice de la Rance in French,
Stankell vordredan ar Renk in Breton) was opened on the 26th November 1966 and is the world's first
electrical generatingElectricity generation is the process of creating electricity from other forms of energy.The fundamental principles of electricity generation were discovered during the 1820s and early 1830s by the British scientist Michael Faraday...
station powered by
tidal energyTidal power, sometimes called tidal energy, is a form of hydropower that converts the energy of tides into electricity or other useful forms of power....
. It is located on the estuary of the
Rance RiverThe Rance is a river of northwestern France. It flows into the English Channel between Dinard and Saint-Malo.Before reaching the Channel, its waters are barred by a 750 metre long dam forming the Rance tidal power plant....
, in
BretagneBrittany is one of the 26 regions of France. It occupies a large peninsula in the northwest of the country, lying between the English Channel to the north and the Bay of Biscay to the south. Its capital is Rennes.-Territory:...
,
FranceFrance , officially the French Republic , is a country located in Western Europe, with several overseas islands and territories located on other continents. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean...
. It is operated by
Électricité de FranceÉlectricité de France is the world’s largest utility company with $95.5 billion in revenues last year, operating a diverse portfolio of 120,000+ megawatts of generation capacity in Europe, Latin America, Asia, the Middle-East and Africa...
(EDF).
This may be one of the very few places in the world where this scheme can work because the power of the tides and the river Rance are used to pump water up into a basin during the times when the water levels are changing.
The
Rance tidal power plant (
Usine marémotrice de la Rance in French,
Stankell vordredan ar Renk in Breton) was opened on the 26th November 1966 and is the world's first
electrical generatingElectricity generation is the process of creating electricity from other forms of energy.The fundamental principles of electricity generation were discovered during the 1820s and early 1830s by the British scientist Michael Faraday...
station powered by
tidal energyTidal power, sometimes called tidal energy, is a form of hydropower that converts the energy of tides into electricity or other useful forms of power....
. It is located on the estuary of the
Rance RiverThe Rance is a river of northwestern France. It flows into the English Channel between Dinard and Saint-Malo.Before reaching the Channel, its waters are barred by a 750 metre long dam forming the Rance tidal power plant....
, in
BretagneBrittany is one of the 26 regions of France. It occupies a large peninsula in the northwest of the country, lying between the English Channel to the north and the Bay of Biscay to the south. Its capital is Rennes.-Territory:...
,
FranceFrance , officially the French Republic , is a country located in Western Europe, with several overseas islands and territories located on other continents. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean...
. It is operated by
Électricité de FranceÉlectricité de France is the world’s largest utility company with $95.5 billion in revenues last year, operating a diverse portfolio of 120,000+ megawatts of generation capacity in Europe, Latin America, Asia, the Middle-East and Africa...
(EDF).
This may be one of the very few places in the world where this scheme can work because the power of the tides and the river Rance are used to pump water up into a basin during the times when the water levels are changing. The electricity is generated by a system identical to a hydro power installation where the water in the basin is sluiced down through the generators 24 hours a day to feed the EDF power grid. So, without a basin at an elevation higher than the barrage, it would not be feasible.
History
An early attempt to build a tidal power plant took place at Aber-Wrac'h in the
FinistèreFinistère is a département of France, located in Brittany .-History:The name Finistère derives from the Latin Finis Terræ, meaning end of the earth, and may be compared with Land's End on the opposite side of the English Channel. Interestingly, the Breton Penn ar Bed translates as Head of the World...
in 1925, but due to financial problems, it was abandoned in 1930. The plans for this plant served as the draft for follow-on work. Use of tidal energy is not an entirely new concept;
Tidal millsA tide mill is a specialist type of water mill driven by tidal rise and fall.A dam with a sluice is created across a suitable tidal inlet, or a section of river estuary is made into a reservoir. As the tide comes in, it enters the mill pond through a one way gate, and this gate closes...
have long existed in areas affected by tides, in particular along the Rance.
The idea of constructing a tidal power plant on the Rance dates to Gerard Boisnoer in 1921. The site was attractive because there is a large average range between low and high tide levels (8 metres, with a maximum equinoctial range of 13.5 metres). The first studies which envisaged a tidal plant on the Rance were done by the Society for the Study of Utilization of the Tides (
Société d'étude pour l'utilisation des marées [SEUM]) in 1943. Nevertheless, work did not actually commence until 1961.
Albert CaquotAlbert Caquot was considered as the "best living French engineer" during half a century. He received the “Croix de guerre 1914-1918” and was Grand-croix of the Légion d’Honneur...
, the visionary engineer, was instrumental in the construction of the dam, designing an enclosure in order to protect the construction site from the ocean tides and the strong streams.
Construction necessitated draining the area where the plant was to be built, which required construction of two dams; an effort which took two years. Construction of the plant proper commenced 20 July 1963, while the Rance was entirely blocked by the two dams.
Construction took three years and was completed in 1966.
Charles de GaulleCharles André Joseph Marie de Gaulle was a French general and statesman who led the Free French Forces during World War II...
, then President of France, inaugurated the plant on 26 November of the same year. Inauguration of the route crossing the plant took place 1 July 1967, and connection of the plant to the French national power grid (EDF)occurred on 4 December 1967.
In total, the plant cost 620 million
FrancThe franc is the name of several currency units, most notably the French franc, the currency of France until it adopted the euro in 1999 , and the Swiss franc, still a major world currency today due to the prominence of Swiss financial institutions...
s - roughly 94.5 Million
EuroThe euro is the official currency of 16 of the 27 Member States of the European Union . The states, known collectively as the Eurozone, are Austria, Belgium, Cyprus, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, Malta, the Netherlands, Portugal, Slovakia, Slovenia and Spain...
s.
The plant produces 0.012% of the power consumed by France, with a peak rating of 240 Megawatts for its 24 turbines. Annual output is about 600 million kWh, or about 68MW average power.
Description
The barrage is 750
metreThe metre or meter is the basic unit of length in the International System of Units . Historically, the metre was defined by the French Academy of Sciences as the length between two marks on a platinum-iridium bar, which was designed to represent one ten-millionth of the distance from the Equator...
s long, from Brebis point in the west to Briantais point in the east. It is located south of
DinardDinard is a commune in the Ille-et-Vilaine department in Bretagne in north-western France.Dinard is on the Côte d'Émeraude of Brittany. Its beaches and mild climate make it a popular holiday destination, and has resulted in the town having a variety of famous visitors and residents...
and Saint Malo, at the mouth of the river.
The power plant portion of the dam is 332.5 metres long. The tidal basin measures 22.5 km².
Turbines
The plant's turbines utilise the energy of the tides and the river current in turn; and as such are bi-directional.
Assessment
In spite of the high cost of the project, the plant's costs have now been recovered, and electricity production costs are lower than for nuclear power generation. (1.8c per kWh, versus 2.5c per kWh for nuclear)
Environmental Impact
The barrage has caused progressive silting of the Rance ecosystem. Sand-eels and
plaicePlaice is the common name of four species of flatfishes:* Alaska plaice, Pleuronectes quadrituberculatus* American plaice, Hippoglossoides platessoides* European plaice, Pleuronectes platessa* Scale-eye plaice, Acanthopsetta nadeshnyi...
have disappeared, though
Sea bass-Fish:Many fish species of various families, including:* Black sea bass , whose range is the eastern coast of the United States...
and
cuttlefishCuttlefish are marine animals of the order Sepiida belonging to the Cephalopoda class . Despite their common name, cuttlefish are not fish but mollusks...
have returned to the river. By definition, tides still flow in the estuary and the operators, EDF endeavours to adjust their level to minimize the biological impact.
Tourist attraction and a bridge
The tidal power plant is of itself a tourist attraction which attracts 200,000 visitors per year. A canal lock in the west end of the dam permits the passage of 16,000 vessels between the
English ChannelThe English Channel is an arm of the Atlantic Ocean that separates England from northern France, and joins the North Sea to the Atlantic. It is about long and varies in width from at its widest, to only in the Strait of Dover...
and the
RanceThe Rance is a river of northwestern France. It flows into the English Channel between Dinard and Saint-Malo.Before reaching the Channel, its waters are barred by a 750 metre long dam forming the Rance tidal power plant....
.
Departmental highway 168 crosses the dam and allows vehicles to travel between
DinardDinard is a commune in the Ille-et-Vilaine department in Bretagne in north-western France.Dinard is on the Côte d'Émeraude of Brittany. Its beaches and mild climate make it a popular holiday destination, and has resulted in the town having a variety of famous visitors and residents...
and
Saint-MaloSaint-Malo is a walled port city in Brittany in north-western France on the English Channel. It is a sub-prefecture of the Ille-et-Vilaine department.-Demographics:...
. There is a
drawbridgeA drawbridge is a type of movable bridge typically associated with the entrance of a castle surrounded by a moat. The term is often used to describe all different types of movable bridges, like bascule bridges and lift bridges.-Castle drawbridges:...
where the road crosses the lock which may be raised to allow larger vessels to pass.
External links