Tuilières power station
| Tuilières power station | |||||||||||
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| Coordinates | 44 ° 50 '42 " N , 0 ° 37' 59" E | ||||||||||
| Data on the structure | |||||||||||
| Lock type: | Run-of-river power plant | ||||||||||
| Height above valley floor: | 31 m | ||||||||||
| Crown length: | 105 m | ||||||||||
| Power plant output: | 32 MW | ||||||||||
| Data on the reservoir | |||||||||||
| Water surface | 0.75 km² | ||||||||||
| Storage space | 7200000 m³ | ||||||||||
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The Tuilières power plant is a French dam in the Dordogne department ( Nouvelle-Aquitaine region ). The structure dams and regulates the central reaches of the Dordogne . It is located in the municipality of Saint-Capraise-de-Lalinde (on the right) and Saint-Agne (on the left).
etymology
The power station Tuilières, French Barrage de Tuilières , was named after the hamlet of Tuilières , which lies immediately downstream and belongs to the municipality of Mouleydier .
geography
The Tuilières power station, sometimes just called the Tuilière power station, is located in a section of steep incline and strong rapids. These are bypassed by the Canal de Lalinde , built in 1844 , which makes it easier for the Gabarren to sail on the Dordogne.
The power plant is operated by EDF and is under the supervision of DREAL Aquitaine .
History from 1905 to 2005
The Tuilières power station was built from concrete between June 1905 and December 1908, with Albert Claveille as the supervising engineer . The dam has a total length of 105 meters. The turbine house currently houses 8 Kaplan turbines with a total output of 32 MW. They generate 148 GWh of electricity a year. At the time of its commissioning in 1909, the power station not only supplied Bergerac and Périgueux with electricity, but also Bordeaux and Angoulême .
In February 1944, underground fighters, French maquisards , blew up several turbines, whereby electricity production came to a complete standstill and thus paralyzed the explosives factory in Bergerac, which was working for the German occupation forces.
The accident of January 29, 2006
On January 29, 2006 at around 3 a.m. there was a serious accident at the power plant. Both counterweights on one of the eight locks had come loose and fell on the contactor below, which was destroyed as a result. As a result, the dam emptied completely - within a few hours 5 million cubic meters of water had leaked. Down the valley there was a drastic increase in the flow rate, which grew from 140 to 480 cubic meters per second. The water level rose in Mouleydier two kilometers downstream by 1.50 meters and was still 0.9 meters higher even in Bergerac, 13 kilometers away. The damage was limited, however, as the water level in the Dordogne was relatively low at the time.
In the following days, four more closures were opened in order to create an unhindered flow and at the same time to allow the fish a free passage.
Upstream the Dordogne found its old profile course of the 19th century and the rapids became visible again. The lacustrine ecosystem was now fundamentally disturbed. The bank lines of the backwater were 10 meters above the river bed, which is why leaks from the nearby Canal de Lalinde and sewage from private households and industrial plants suddenly became visible.
The prefecture then banned fishing and water sports in the area of the former reservoir.
technical description
The run-of-river power plant was fitted with eight metal weir locks to take account of the very variable flow rates of the Dordogne . The locks can be raised to a final height of 17.76 meters and thus exceed the highest known water level in the Dordogne of 15 meters - measured in 1783. Each lock can be controlled individually. This is done using two counterweights, each weighing 80 tons, which are located a maximum of 30 meters above the retracted lock.
Complementary to the turbines driven by water power, the power plant has been equipped with a conventional thermal coal heating system since its commissioning, the two turbines of which also step in when the water levels are low in summer or during major floods. These additional turbines were in service until 1950, but were then dismantled.
Redesign
After the accident, the power plant was repaired to improve its stability against earthquakes and thousand-year floods. For this reason, the dam was raised by four meters. The system of counterweights was abandoned. All metal structures were renewed by the Joseph Paris company from Nantes.
In order to guarantee better fish migration - especially of the salmon - the turbines were provided with masks so that the schools can be directed to the actual passages. The turbines are now switched off temporarily to allow the young eels to pass through .
The cost of the reconstruction of the dam and turbine house totaled 35 million euros, with 5 million euros being spent on improving fish migration alone. On January 20, 2009, the new build began and the resumption of power generation was planned for the period May 18 to 29, 2009.
geology
At Saint-Capraise-de-Lalinde, the Dordogne, which flows in a westerly direction, cut by almost 100 meters into the Mesozoic and Cenozoic layers of the Aquitaine basin . Upcoming are limestone from the Campanian and continental sands from the Eocene .
The sequence includes in detail Upper Campan (Campanium 5) and Middle Eocene. The upper campan begins with 20 meters thick, yellow to white colored bioclastic limestone. Above it follow 50 meters of reddish colored sandy limestone, rich in cavities, small sloping layers and synsedimentary landslides. Against the hanging wall bioclastic limestones with scattered reappear rudists -Biostromen. The fluvial and discordant overlying Middle Eocene is 20 to 40 meters thick and consists of gravels with gray quartz or quartzite pebbles at the base, followed by gray to green, feldspar-containing sands and green-marbled clays.
The Dordogne river valley is filled by an alluvial terrace from the last Ice Age ( Würm ), 6 in places up to 12 meters thick , which has recently been eroded by the river. Remains of even older terraces have been preserved on the slopes ( Riss and even Old Pleistocene ).
ecology
In order not to prevent fish migration on the Dordogne, a fish ladder was installed from the start. However, the original design was wrongly designed so that the fish could not overcome the obstacle. An amendment in 1910 brought no improvement. A lift was therefore added in 1989 and a new staircase in 1997. However, a free passage is still not guaranteed.
Photo gallery
View from Saint-Agne towards the power station
Complete complex of turbine house and dam
Downstream side of the turbine house
The backwater 2 kilometers above the dam
Newly installed fish elevator
.JPG)
literature
- J.-P. Platel: Bergerac . In: Carte géologique de la France at 1/50 000 . BRGM, 1999.
