Aarau power plant

Aarau power plant
The power plant seen from the underwater side. Engine house from 1912 with a new building from the 1960s
location
Coordinates	645090  /  249503
country	Switzerland  Aargau
place	Aarau
Waters	Aare
Height upstream	374  m above sea level M.
power plant
owner	Eniwa AG
Start of planning	1870s
construction time	1893–1894, expanded 1912–1913
Start of operation	August 15, 1894
technology
Bottleneck performance	16.08 megawatts
Average height of fall	6.4 m
Expansion flow	394 m³ / s
Standard work capacity	101.62 million kWh / year
Turbines	11 Kaplan and propeller turbines
Others
Associated weir	Day moss ▼
Website	www.eniwa.ch
was standing	2020

The Aarau power plant is a run-of-river power plant on the Aare in the Swiss city of Aarau . The power plant was commissioned in 1894 and is operated by Eniwa AG . It is to be fundamentally renewed in the 2020s.

history

At the beginning of the 1870s, on the initiative of the cement factory owner Albert Fleiner, a commercial sewer was created, but due to the crash of the founders, it was not equipped with a turbine until 1880 that drove the cement mill via a mechanical transmission .

In 1893, the municipality of Aarau bought the commercial sewer to use it to generate electricity. The cement factory retained the right to use a third of the available hydropower. She therefore installed a 200 HP Jonval turbine in the newly constructed nacelle on her own account to drive the transmission, while two Francis turbines from Rieter with generators from Brown, Boveri & Cie. (BBC) generated electricity for the city. The plant started operating on August 15, 1894. After the power plant started operating, a new weir was built at the inlet of the commercial sewer. The power station had an absorption capacity of 22 m³ / s. The cement factory sold its stake in the power station in 1903.

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  The first central building of the Aarau electricity works from 1894

Expansion in 1913

The power station was expanded in 1912 and 1913 by a second canal north of the existing commercial canal. The damming of the power plant begins 600 m below the Schönenwerd bridge , the water is returned 200 m above the chain bridge in Aarau. In total, 4.1 km of the Aare watercourse are used from the start of the backwater until the water is returned. Most of the damming lies on Solothurn soil, which is why this canton has a sovereign share of 82% and Aargau only one of 18%.

In the new machine house with a tower like a city gate , two triple vertical Francis turbines in a tiered design were initially installed, as well as an exciter turbine . The main turbines manufactured by Bell Maschinenfabrik each had an output of 1,600 hp, the exciter turbine had an output of 250 hp. It was single phase and Zweiphasenwechseltrom with a frequency generated by 40 Hz. The voltage was 6100 V for the single-phase current and 4000 to 4400 V for the two-phase current. Presumably in 1929 the company switched to three-phase alternating current .

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  Bell multi-deck turbine

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  Representation of the power plant on the Siegfried map. Data status 1913

After a renovation in the 1960s, nine Kaplan , one propeller and one Francis turbines were in operation in the two machine houses . As early as 1959, a propeller turbine with an output of 230 kW was put into operation, which processes the residual water at the weir in Tägermoos before it flows into the natural Aare bed.

Renewal in the 2020s

As part of the new concession, the existing machine house is to be demolished and replaced by a mostly underground power plant in which three bulb turbines will generate electricity. The new system should produce 20% more electricity compared to the old one. If the project is approved by the cantons, it could go online as early as 2024 as of 2019.

Web links

Commons : Aarau power station  - collection of images, videos and audio files

Individual evidence

1. ^ Competitions: Construction of a weir . In: Schweizerische Bauzeitung . tape 24 , October 13, 1894, pp. 109 ( e-periodica.ch ).
2. ↑ ^{a b} Federal Office for Water Management (Ed.): Statistics of the hydropower plants in Switzerland . January 1, 1973, p. 94-95 ( admin.ch ).
3. ↑ Statistics on hydropower plants in Switzerland . January 1, 1914, p. 270-271 ( admin.ch ).
4. ↑ Federal Office for Water Management (Ed.): Statistics on hydropower plants in Switzerland . January 1, 1928, p. 292–293 ( admin.ch ).
5. ^ Aarau power plant - Completely new plans for river power plant. In: Regional journal Aargau Solothurn. Swiss radio and television, January 11, 2019, accessed on June 21, 2020 . 

 Map with all coordinates: OSM | WikiMap