Latvian power plant
| Latvian power plant | |||
|---|---|---|---|
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| location | |||
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| Coordinates | 682 632 / 249041 | ||
| country | Switzerland | ||
| Waters | Limmat | ||
| Data | |||
| Type | Canal power plant | ||
| Primary energy | Hydropower | ||
| power | 4.2 MW | ||
| owner | Electricity company of the city of Zurich | ||
| Project start | 1874 | ||
| Start of operations | 1878 | ||
| turbine | Two Kaplan turbines | ||
| Energy fed in per year | 21 GWh | ||
| Website | Lettenstrom | ||
The power station Letten is a hydroelectric power plant in the area Latvians the town of Zurich in canton Zurich . It is one of the first hydropower plants with a pumped storage pond in Switzerland and the oldest in the city of Zurich. This monument to industrial history belongs to the city of Zurich's power station (EWZ).
Waterworks
The municipal water supply, founded in 1868, decided to distribute drinking and service water via two independent pipe networks. There were over 100 sources on the Zürichberg, Uetliberg and Albis for the drinking water supply. From 1874, the water from the Limmat was used to drive pumps which, in addition to drinking water, transported filtered water from Lake Zurich as process water to various reservoirs on the Zurichberg.
As the heart of the new water supply, the longitudinal buildings on the right bank of the Limmat were built for the Letten waterworks from 1876 to 1878 to operate the pumps with the canalized water wheels.
The process water or "driving water" was conducted from Lake Zurich through a 90 cm wide cast iron pipe laid in the Schanzengraben to the filter system (sand filter) on Hafnerstrasse and on to the Letten pumping station. From there, five pump systems pumped the water in risers into the reservoirs at different heights (three pressure zone areas) and the "Resiweiher" (Resi von Reservoir) created in 1882 on the Zürichberg . The "driving water" from the reservoirs was fed to various commercial establishments for energy supply, where it drove water motors (similar to the spin dryer ). The "Resiweiher" was therefore also called "Triebwasserweiher".
The eight reaction turbines of the Letten waterworks, driven by the Limmat water, transmitted their energy to a common transmission shaft, which was used to drive the five pumps and, from 1878, to transmit mechanical energy to the industrial quarter.
The Lettenwerk included the 50 m long needle weir at Platzspitz with a water level of 2.5 m, the 700 m long upper water canal, the turbine system with pumping station and a 350 m long underwater canal. When the energy from hydropower was insufficient, steam engines powered by coal were also put into operation. On old photos you can see the two chimney chimneys.
From 1878, in addition to the water supply by means of wire rope transmission, mechanical energy was supplied to the industrial quarter for a silk twisting mill, mechanical workshops, a silk dyeing factory and the town mill, as well as the Hofmeister calico factory. A wire rope hoist carried the output of approx. 220 kW (300 PS ) from the turbines in the waterworks over a 1.2 km long transmission to drive rollers and gears in the industrial area on the left bank of the river via chains and belts. Of two of the six transmission towers that diverted the mechanical energy, the bases opposite the power station on the left side of the river have been preserved.
Machine hall 1881
Rope transmission 1883
Letten power plant with rope transmission 1892
KW Letten with high chimneys for steam dynamos, around 1900
Power station
The Letten waterworks, which was expanded into an electricity company in 1892, was able to supply electrical energy from 1893, which was supplemented by steam energy from coal in arid winters. The "Resiweiher" reservoir has now become a pumped storage lake. If the pumped storage power plant produced excess electricity, water was pumped into the pond. During the consumption peaks, the water from the "Resiweiher" was allowed to flow back down onto the turbines.
With the simultaneous incorporation of the suburbs, the need of households, factories and trams (instead of the Rösslitrams ) for electrical energy for motors, machines, heating and household appliances increased sharply. From 1898 onwards, steam engines were used alongside water power to bridge periods of low water.
The city of Zurich tried to cover the additional demand with hydropower outside the city and canton area: From 1904 with electricity from the Aare power station in Beznau. In 1906 the city had the Albula power plant built in Sils Domleschg.
In 1910 the Letten power plant (water and steam power plant) supplied 4.8%, the Beznau hydroelectric power plant 13% and the Albula power plant near Sils 82% of the electricity required in Zurich. Between 1909 and 1917, the electricity consumption of the people of Zurich rose from 77 kWh per capita per year to 143 kWh. The needle weir was replaced after 1935 by a new weir system, which was set up for an average water level of 406 m . In 1938 the transverse higher building was built.
With a total renovation of the power plant in Latvia in 1951/52, electricity production could be increased and the regulation of the lake water level improved with a hydraulic weir at Platzspitz.
A new fish ladder has existed since 2010 , which enabled the “nature star” certification. The catchment area of KW Letten is 1,829 km², the process water volume is 25–100 m³ / s and the gross gradient is 4.5–5.3 meters.
Today's production
The electricity generated on the Letten was previously offered as part of an electricity mix product. Since 2006, the people of Zurich have been able to obtain the more expensive, ecological electricity from the Letten power station, which is enough for almost 7,000 households. The EWZ offers guided tours at the former location for Lettenstrom customers.
See also
literature
- Daniel Kurz: Letten power plant. In: Calico printing works, dental gold for the whole world, dying shops. Wipkingen habitats-traffic areas. History of a Zurich City Quarter 1893–1993 . Quartierverein Wipkingen / GGW - Chronos Verlag, 1993.
- W. Wyssling: The development of the Swiss electricity works and their components . Swiss Electrotechnical Association , 1946.
Web links
Individual evidence
- ↑ Tagesanzeiger: When the Letten power plant was still pumping water on the Zürichberg
- ^ Daniel Kurz: Kraftwerk Letten . In: Calico printing works, dental gold for the whole world, dying shops. Wipkingen habitats-traffic areas. History of a Zurich city quarter 1893-1993 .
- ↑ Swiss construction newspaper of October 31, 1968: 75 years of the city of Zurich's electricity company
- ↑ Lettenstrom ( Memento of the original dated August 12, 2018 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ^ EWZ: Letten power plant
- ^ Quartierverein Wipkingen: Daniel Kurz: K attundruckereien, Zahngold for the whole world, shop dying .
