Rance tidal power plant
Encyclopedia
The Rance Tidal Power Station is the world's first tidal
power station and also the world's second biggest tidal power station. The facility is located on the estuary of the Rance River
, in Brittany
, France
. Opened on the 26th November 1966, it is currently operated by Électricité de France
, and is the second largest tidal power station in the world, in terms of installed capacity. With a peak rating of 240 Megawatts, generated by its 24 turbines, it supplies 0.012% of the power demand of France. With a capacity factor
of approximately 40%, it supplies an average 96 Megawatts, giving an annual output of approximately 600 GWh. The barrage
is 750 m (2,461 ft) long, from Brebis point in the west to Briantais point in the east. The power plant portion of the dam is 332.5 m (1,091 ft) long. The tidal basin measures 22.5 square kilometre.
An early attempt to build a tidal power plant was made at Aber Wrac'h
in the Finistère
in 1925, but due to insufficient finance, it was abandoned in 1930. Plans for this plant served as the draft for follow-on work. Use of tidal energy is not an entirely new concept, since tidal mills
have long existed in areas exposed to tide
s, particularly 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 of the wide average-range between low and high tide levels, 8 m (26 ft) with a maximum perigean spring tide range of 13.5 m (44.3 ft). The first studies which envisaged a tidal plant on the Rance were done by the Society for the Study of Utilization of the Tides in 1943. Nevertheless, work did not actually commence until 1961. Albert Caquot
, 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 commenced on the 20th of July 1963, while the Rance was entirely blocked by the two dams.
Construction took three years and was completed in 1966. Charles de Gaulle
, then President of France, inaugurated the plant on the 26th of November of the same year. Inauguration of the route crossing the plant took place on the 1st of July 1967, and connection of the plant to the French National Power Grid was carried out on the 4th of December 1967. In total, the plant cost
₣
620 million (approximately €
94.5 million).
generation (1.8c per kWh, versus 2.5c per kWh for nuclear).
have disappeared, though sea bass
and cuttlefish
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.
and the Rance
. Departmental highway 168 crosses the dam and allows vehicles to travel between Dinard
and Saint-Malo
. There is a drawbridge
where the road crosses the lock which may be raised to allow larger vessels to pass.
Tidal power
Tidal power, also called tidal energy, is a form of hydropower that converts the energy of tides into useful forms of power - mainly electricity....
power station and also the world's second biggest tidal power station. The facility is located on the estuary of the Rance River
Rance River
The 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 Brittany
Brittany
Brittany is a cultural and administrative region in the north-west of France. Previously a kingdom and then a duchy, Brittany was united to the Kingdom of France in 1532 as a province. Brittany has also been referred to as Less, Lesser or Little Britain...
, France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
. Opened on the 26th November 1966, it is currently operated by Électricité de France
Électricité de France
Électricité de France S.A. is the second largest French utility company. Headquartered in Paris, France, with €65.2 billion in revenues in 2010, EDF operates a diverse portfolio of 120,000+ megawatts of generation capacity in Europe, Latin America, Asia, the Middle East and Africa.EDF is one of...
, and is the second largest tidal power station in the world, in terms of installed capacity. With a peak rating of 240 Megawatts, generated by its 24 turbines, it supplies 0.012% of the power demand of France. With a capacity factor
Capacity factor
The net capacity factor or load factor of a power plant is the ratio of the actual output of a power plant over a period of time and its potential output if it had operated at full nameplate capacity the entire time...
of approximately 40%, it supplies an average 96 Megawatts, giving an annual output of approximately 600 GWh. The barrage
Tidal barrage
A tidal barrage is a dam-like structure used to capture the energy from masses of water moving in and out of a bay or river due to tidal forces....
is 750 m (2,461 ft) long, from Brebis point in the west to Briantais point in the east. The power plant portion of the dam is 332.5 m (1,091 ft) long. The tidal basin measures 22.5 square kilometre.
History
Aber Wrac'h
The Aber Wrac'h is a small village and port located on the Wrac'h river in the commune of Landéda in the department of Finistère in France, located in Brittany.The Wrac'h river source is Trémaouézan...
in the Finistère
Finistère
Finistère is a département of France, in the extreme west of 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...
in 1925, but due to insufficient finance, it was abandoned in 1930. Plans for this plant served as the draft for follow-on work. Use of tidal energy is not an entirely new concept, since tidal mills
Tide mill
A tide mill is a 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 automatically when the tide...
have long existed in areas exposed to tide
Tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the moon and the sun and the rotation of the Earth....
s, particularly along the Rance
Rance River
The 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....
.
The idea of constructing a tidal power plant on the Rance dates to Gerard Boisnoer in 1921. The site was attractive because of the wide average-range between low and high tide levels, 8 m (26 ft) with a maximum perigean spring tide range of 13.5 m (44.3 ft). The first studies which envisaged a tidal plant on the Rance were done by the Society for the Study of Utilization of the Tides in 1943. Nevertheless, work did not actually commence until 1961. Albert Caquot
Albert Caquot
Albert 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 commenced on the 20th of July 1963, while the Rance was entirely blocked by the two dams.
Construction took three years and was completed in 1966. Charles de Gaulle
Charles de Gaulle
Charles André Joseph Marie de Gaulle was a French general and statesman who led the Free French Forces during World War II. He later founded the French Fifth Republic in 1958 and served as its first President from 1959 to 1969....
, then President of France, inaugurated the plant on the 26th of November of the same year. Inauguration of the route crossing the plant took place on the 1st of July 1967, and connection of the plant to the French National Power Grid was carried out on the 4th of December 1967. In total, the plant cost
₣
French franc
The franc was a currency of France. Along with the Spanish peseta, it was also a de facto currency used in Andorra . Between 1360 and 1641, it was the name of coins worth 1 livre tournois and it remained in common parlance as a term for this amount of money...
620 million (approximately €
Euro
The euro is the official currency of the eurozone: 17 of the 27 member states of the European Union. It is also the currency used by the Institutions of the European Union. The eurozone consists of Austria, Belgium, Cyprus, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg,...
94.5 million).
Assessments
In spite of the high development cost of the project, the costs have now been recovered, and electricity production costs are lower than that of nuclear powerNuclear power
Nuclear power is the use of sustained nuclear fission to generate heat and electricity. Nuclear power plants provide about 6% of the world's energy and 13–14% of the world's electricity, with the U.S., France, and Japan together accounting for about 50% of nuclear generated electricity...
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
Plaice is the common name of four species of flatfishes.Plaice or PLAICE may also refer to:* USS Plaice , a Balao-class submarine* PLAICE, an open source hardware FLASH programmer, memory emulator, and logic analyzer...
have disappeared, though sea bass
European seabass
The European seabass, Dicentrarchus labrax, also known as Morone labrax, is a primarily ocean-going fish that sometimes enters brackish and fresh waters. It is also known as the sea dace...
and cuttlefish
Cuttlefish
Cuttlefish are marine animals of the order Sepiida. They belong to the class Cephalopoda . Despite their name, cuttlefish are not fish but molluscs....
have returned to the river. By definition, tides still flow in the estuary and the operators, EDF
Électricité de France
Électricité de France S.A. is the second largest French utility company. Headquartered in Paris, France, with €65.2 billion in revenues in 2010, EDF operates a diverse portfolio of 120,000+ megawatts of generation capacity in Europe, Latin America, Asia, the Middle East and Africa.EDF is one of...
endeavours to adjust their level to minimize the biological impact.
Tourist attraction
The facility attracts approximately 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 ChannelEnglish Channel
The English Channel , often referred to simply as the Channel, is an arm of the Atlantic Ocean that separates southern 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 in the Strait of Dover...
and the Rance
Rance River
The 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 Dinard
Dinard
Dinard is a commune in the Ille-et-Vilaine department in Brittany 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 this has resulted in the town having a variety of famous visitors and residents...
and Saint-Malo
Saint-Malo
Saint-Malo is a walled port city in Brittany in northwestern France on the English Channel. It is a sub-prefecture of the Ille-et-Vilaine.-Demographics:The population can increase to up to 200,000 in the summer tourist season...
. There is a drawbridge
Drawbridge
A 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.