Bannwil power plant

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Bannwil power plant
Power plant in 1983
Power plant in 1983
location
Bannwil power plant (Canton of Bern)
Bannwil power plant
Coordinates 622261  /  230940
country Switzerland
place Bannwil
Waters Aare
Height upstream 410  m above sea level M.
power plant
owner BKW energy
operator dito
construction time 1966-1970
Start of operation 1970
technology
Bottleneck performance 26.8 megawatts
Average
height of fall 		7.2-9.0 m
Expansion flow 435 m³ / s
Turbines 3 × tube turbine
Others
Energy fed in since commissioning 149 GWh
Website BKW
was standing 2020
Wangen power station (1904–1969)
Machine house in Bannwil
Machine house in Bannwil
location
Coordinates 622525  /  231574
country Switzerland
place Bannwil
Waters Aare
f1
power plant
owner until 1916: Wangen electricity works
from 1916: BKW
Start of planning Concession 1898
construction time 1900-1905
Start of operation 1904
Shutdown 1969
technology
Bottleneck performance 7.7 megawatts
Average
height of fall 		7–9 m
Expansion flow 120 m³ / s
Turbines 7 × quadruple Francis turbine
Others
Energy fed in since commissioning 3385 GWh
was standing 1926

The Bannwil hydropower plant is a run-of-river power plant near Bannwil that went into operation in 1970. It replaced the Wangen an der Aare power station , which was commissioned as a diversion power station in 1904 .

history

Wangen an der Aare power station (1904–1969)

The concession for the first power station in Bannwil was granted to the communities of Wangen , Wiedlisbach , Walliswil bei Wangen , Walliswil bei Niederbipp , Berken , Bannwil and Graben on July 6, 1898. However, the construction of the plant exceeded the financial possibilities of the municipalities with a total of almost 5,000 inhabitants, which is why the concession was sold to the German Society for Electrotechnical Companies from Frankfurt am Main in July 1899 . The company, which previously operated under the name W. Lahmeyer & Cie , began building the power plant in 1900. It supplied all the electrical equipment and the high-voltage lines except for two generators, which came from Maschinenfabrik Oerlikon (MFO). The turbines were supplied by Escher Wyss from Zurich .

While the power plant was being built, the company Elektrizitätswerk Wangen was founded for its operation , whose place of business was in Wangen an der Aare , according to its name . The power plant went into operation in 1904 after a five-year construction period. The construction costs amounted to 11.2 million SFr ., Which is a monetary value of 100 million SFr. in 2020.

In the Fahrhöfli ⊙ area, the canal wall broke at least twice. In this area, the canal runs right next to the Aare and was only separated from it by a wall. In August 1905, when the water level in the Aare was high, the foundation of the wall gave way in the difficult terrain there, causing the entire amount of water to escape from the canal. The power plant was out of operation for several months and the damage amounted to between CHF 250,000 and CHF 300,000.

In 1912, on July 26th, an oil switch explosion occurred in the machine house. The large fire that broke out caused severe damage to the high-voltage system, the machine sets and the building, so that the power plant was inactive for a year.

In 1916, the share capital of Elektrizitätswerk Wangen was taken over by the Bernische Kraftwerke (BKW), in 1919 BKW also took over the staff of the electricity company and finally bought the power station in 1941.

The plant remained in operation until 1969, producing 3.385 TWh during the sixty years of operation. After the opening of the new power plant, the canal to the old power plant was filled in, except for the part of the canal that passed north of the Stadtfeld and was preserved as the arm of the Aaren. Behind the filled-channel formed on the site of the parade ground a wetland, ⊙ was placed under protection.

technology

For the power plant, a 8.4 km long headrace channel is created, the above cheeks by the river through a 120 meter long dam at Weiler Hohfuren ⊙ was discharged and the Aar followed on the north side. The weir dammed the Aare around 1.7 km to the border with the canton of Solothurn .

The machine house stood south of Bannwil on the banks of the Aaren ⊙ ; the underwater channel back into the river was only 84 meters long. By 1908 six horizontal-axis quadruple Francis turbines were installed, which directly drove the three-phase generators . The seventh turbine chamber was not occupied with another turbine until the summer of 1909. Each turbine had an output of 1500 HP at 150 revolutions per minute and drove a three-phase generator. Two small Girard turbines were used to drive the oil pressure pumps for the turbine governors.

Picture gallery

  • Weir at the hamlet of Hohfuren

  • Engine house with upper water canal.jpg

  • Broken canal wall in Fahrhöfli 1905

  • Central fire in 1912

  • Control wall in the old power plant

  • The seven machine groups in the machine house. The two Oerlikon generators are machines 2 and 3.

  • Quadruple Francis turbine (Escher Wyss plant)

New power plant from 1970

In 1970 the new power plant was put into operation. It was built as a block power plant with three frontally arranged power plant inlets, each with a bulb turbine. The installed capacity is 28.5  MW and the average annual production 150 GWh. The water of the Aare is turbined in three Kaplan bulb turbines, whereby a gradient between 5.5 m and 8.5 m can be used depending on the water level. The turbines process a usable volume of up to 450 m³ / s.

The Bannwil hydropower plant is operated by BKW .

The island Vogelraupfi , which is under nature protection, is located in the dam of the power plant .

Picture gallery

  • Folding apron during the construction period of the new power plant

  • The folding aprons during the construction period of the new power plant

  • Underwater side of the power plant under construction

  • Upper water side of the power plant's machine house under construction

  • The open folding aprons

See also

literature

  • L Zodel: Large modern turbine systems . In: Schweizerische Bauzeitung . tape 47 , 1906, 8. The Wangen ad Aare power station.
  • Hubert Rohner: The Wangen electricity company . In: Neujahrsblatt Wangen an der Aare .
    • Part 1 . 2000, p. 35–44 ( unibe.ch [PDF]).
    • Part 2 . 2001, p. 25–32 ( unibe.ch [PDF]).
    • Part 3 . 2002, p. 15–20 ( unibe.ch [PDF]).

Web links

Commons : Kraftwerk Bannwil  - Collection of images, videos and audio files

Individual evidence

  1. ↑ a b Kathrin Holzer: When the power plant was still on the canal. In: Langenthaler Tagblatt. May 26, 2017, accessed May 19, 2020 .
  2. ↑ Wangen electricity works . In: EDI, Department for Water Management (Ed.): The water forces of Switzerland . January 1, 1914, p. 39 ( admin.ch ).
  3. ^ Robert Thomann: The water turbines . 2012, ISBN 978-5-87934-430-1 ( limited preview in Google book search [accessed on May 19, 2020]): "two water eruptions"
  4. ^ Miscellanea . Wangen an der Aare power station. In: Schweizerische Bauzeitung . tape 45 , August 19, 1905, p. 103 ( e-periodica.ch ).
  5. ↑ Hubert Rohner, Part 3 , p. 26
  6. ↑ Karl Ludwig Schmalz: A nature reserve on the arms place Wangen . In: Yearbook of the Oberaargau . 1977, p. 29–31 ( unibe.ch [PDF]).
  7. ↑ Electricity works Wangen of A.-G. Electricity Wangen . In: Schweizerischer Wasserwirtschaftsverband (Ed.): Guide through the Swiss water management . tape 1 , 1926, pp. 535-538 .
  8. ↑ Yearbook of Oberaargau 1959
  9. ^ Anne-Marie Dubler : Bannwil. In: Historical Lexicon of Switzerland . September 15, 2009 , accessed July 7, 2019 .
  10. ↑ Bannwil hydropower plant. In: BKW. BKW, accessed on May 18, 2016 .