Thun power plant

AAREwerk62 and AAREwerk94
Left AAREwerk62, right AAREwerk94
location
Coordinates	613 953  /  178960 coordinates: 46 ° 45 '42 "  N , 7 ° 37' 17"  O ; CH1903:  613953  /  178960
country	Switzerland  Bern
place	Tuna
Waters	Aare
Height upstream	556.14  m above sea level M.
power plant
owner	Energy Thun
Start of operation	1. Electricity company: 1896 2. Electricity company: 1917 AAREwerk62: 1962 AAREwerk94: 1994
Shutdown	1st power station: around 1960 2nd power station: around 1992
technology
Bottleneck performance	1. Electricity plant: 0.45 MW 2. Electricity plant: 1.75 MW AAREwerk62: 6.2 MW AAREwerk94: 2.8 megawatts
Average height of fall	6.5 m
Expansion flow	AAREwerk62: 70 m³ / s AAREwerk94: 50 m³ / s
Standard work capacity	AAREwerk62 + AAREwerk94: 38 million kWh / year
Turbines	AAREwerk62: 2 × vertical Kaplan turbines AAREwerk94: 1 × S turbine
Others
Website	Energy Thun
was standing	2018

The Thun power plant consists of two run-of-river power plants on the Aare , which Energie Thun uses to supply the city of Thun with local electricity . They are referred to as AAREwerk62 and AAREwerk94 after the year they went into operation , and together they emit 38 GWh into the public grid each year, which corresponds to roughly a fifth of the city of Thun's electricity needs. The previous systems from 1896 and 1917 are more in operation and have been dismantled.

history

The hydropower of the Aare was used in Thun even before electricity was introduced. Thun already had water wheels in the Middle Ages. The Lanzrein mill installed turbines for the mechanical drive of the painting works in the 1880s. Later, a 100 hp generator was used in the mill to generate electricity for its own use.

In 1883, Thun built a commercial canal with a turbine that mechanically powered the city's groundwater pumping station. In 1891 a direct current generator was installed in the pumping station. In 1896 the pumping station was converted to electrical operation. The first power plant in the city of Thun, then still called the Thun municipal power station , used the water from the commercial canal. The electricity was not only used to drive the pumping station, but also for electrical city lighting. In 1906 the facility was expanded and a steam power plant was built so that enough electricity could be produced even when there was a lack of water.

The existing power plant was no longer sufficient for the growing energy demand, so that a new power plant had to be built in 1917, which was still operated with water from the commercial sewer. The facilities from 1896 continued to be used for the time being and only had to give way to the new building decided in 1958, which was later called AAREwerk62. This power plant was no longer built as a diversion power plant, but integrated into the weir on the Aare. It was supplemented in 1994 by the AAREwerk94, to which the power plant from 1917 had to give way.

technology

Municipal power station 1896

In the power plant on Scheibenstrasse, there were turbines that were supplied by Bell Maschinenfabrik . According to the hydropower statistics of 1928, four turbines were installed. A 180 horsepower and 75 horsepower turbine supplied current to the Swiss Metallwerke Selve & Co . , two 180 HP turbines were used for general electricity supply as a reserve and for power generation during the night. The system was in operation until the AAREwerk62 was built.

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  Municipal power station 1896

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  Extended power station from 1896 during the construction of the power station in 1917

Electric power station in 1917

The power plant, which went into operation in 1917, was equipped with two vertical Francis turbines from Escher Wyss AG in Zurich . Each turbine had an output of 715 hp at a nominal speed of 150 min ⁻¹ and drove a 650 kVA generator from Maschinenfabrik Oerlikon . In 1935 an additional Kaplan turbine with an output of 1430 hp was installed. The system was in operation until the AAREwerk94 was built.

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  The power station in 1917 on the right bank, in the river the AAREwerk62. Photo from 1991

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  Machine room in 1991

AAREwerk62

The power plant stands across the river bed, and the Aare is dammed by a damper weir. Two vertical Kaplan turbines that were renewed between 2010 and 2012 are installed in the machine house. The diameter of the running wheels is 3.5 m. The generators have a speed of 107 min ⁻¹ and a nominal output of 4.2 MVA. In winter 2017/2018 the first turbine and in winter 2018/2019 the second turbine was converted to PEEK- coated support bearings, which cause lower friction losses and are more temperature- resistant than white metal-coated bearings.

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  Kaplan turbine in the AAREwerk62

AAREwerk94

The power plant replaced the system from 1917. It consists of a single S-turbine with an impeller 2.8 m in diameter that rotates at 144 min ⁻¹ . The generator is connected to the turbine via a gearbox and has an output of 3.75 MVA at a speed of 1000 min ⁻¹ .

Individual evidence

1. ↑ ^{a b} Jungfrau Zeitung: A world first in the Aare works. 17th February 2019 . 
2. ↑ ^{a b} Anna Bähler: Tamed and used: The city of Thun and the water in the last 300 years . In: Bern journal for history . tape 69 , no. 03 , 2007, p. 170, 174, 175 ( bezg.ch [PDF]).
3. ↑ Federal Office of Energy (Ed.): Statistics of the hydropower plants in Switzerland . 1914 (Appendix No. 15).
4. ↑ Thun electricity works . In: Illustrated Swiss craft newspaper . tape 11 , no. 36 , 1895, pp. 587 .
5. ↑ Federal Office of Energy (Ed.): Statistics of the hydropower plants in Switzerland . 1928 (Appendix No. 14a and 14b).
6. ↑ Federal Office of Energy (Ed.): Statistics of the hydropower plants in Switzerland . 1947 (Appendix No. 4).
7. ↑ Energie Thun (ed.): Thuner AAREstrom. Homemade and fish friendly. S. 10 ( energiethun.ch [PDF]).