Walchensee power plant
| Walchensee power plant | |||
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| Coordinates | 47 ° 37 '49 " N , 11 ° 20' 15" E | ||
| country | Germany | ||
| Waters | Walchensee , Isar | ||
| Data | |||
| Primary energy | Hydropower | ||
| power | 124 MW (4 × 18 MW, 4 × 13 MW) | ||
| owner | Uniper power plants | ||
| Start of operations | 1924 | ||
| turbine | 4 × Francis turbine 4 × Pelton turbine |
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| Website | www.uniper.energy | ||
| was standing | 2016 | ||
The Walchensee power plant is a high-pressure storage power plant that was commissioned in 1924 in Kochel am See in Bavaria . With an installed capacity of 124 MW, it is still one of the largest of its kind in Germany. It has been owned by Uniper Kraftwerke GmbH since 2016 .
description
The Walchensee power plant uses water power at a natural gradient of a good 200 m between the Walchensee ( 801 m above sea level ), which functions as the "upper basin" and the "lower basin" Kochelsee (600 m above sea level) to generate electricity. During the operation of the power plant, the water level of the Walchensee may be lowered by around 6 m, which corresponds to an available storage space of 110 million m³. It is therefore a storage power plant , but not a pumped storage power plant , as no water is pumped back into the Walchensee. It was originally built for the general power supply, but today it mainly serves as a peak load and, depending on the water supply, also as a medium load power plant .
Reservoirs and tributaries
The natural tributaries of the Walchensee are not sufficient to provide enough water for the storage power plant to operate continuously. The Walchensee power plant is therefore the central system of a spacious network of additional weirs, canals and tunnels with which the water flow to the Walchensee is increased. The Walchensee receives the additional water it needs with the Isar and Rißbach bridges. In order to also be able to use the energy of the gradient of these additional tributaries, additional power plants (Obernach- / Niedernachwerk) were built into these systems. The natural outflow of the Walchensee near Niedernach - over the Jachen to the Isar - is blocked by a weir . In order to keep the water level of the Kochelsee as stable as possible, its outflow is regulated in a lock channel near Kochel. In order to protect the flat Loisach Valley and Wolfratshausen from flooding by the water from the power plant, the Loisach-Isar Canal provides additional drainage into the Isar.
Due to the power plant operation and the resulting fluctuating water level, both lakes hardly freeze over in winter. That is why the ice surfaces in the individual bays are thin and must not be stepped on.
Isar transition
The amount of water coming from the Walchensee catchment area is not sufficient for the operation of the power plant. It was therefore planned from the start to channel the water from the Isar into the Walchensee. The Isar comes as a wild water river from the Austrian part of the Karwendel Mountains . It was dammed between Mittenwald and Krün at river kilometer 251.5 by the Krün weir by five meters to the Isar reservoir (870 m) and from there almost completely transferred to the Walchensee. Since 1990, however, a minimum amount of water has to remain in the original course of the river (between 3 and 4.8 m³ / s, depending on the season). A small run-of-river power plant was built there in 1990 in order to be able to use the 5 m gradient of the remaining water at the weir to generate electricity . The transferred Isar water first flows in an open canal through Krün to Wallgau. On this route, the water from the Kranzbach and Finzbach streams is fed into the canal in underground pipes . Before Wallgau crosses the canal in a culvert , the federal highway 11 and mostly dry bed of Finzbaches and is guided by Wallgau through a tunnel to Sachensee (867 m). The Sachensee is also slightly dammed and regulated by a weir. Originally the water flowed through the Obernach Canal over several steep steps (the so-called Isarfall) to the north, crossed the premises of the Research Institute for Hydraulic Engineering and Water Management of the Technical University of Munich and finally flowed into the Walchensee at Einsiedl . In the 1950s, it was decided to use the gradient between the Sachensee and Walchensee and built the Obernach power plant , which was commissioned in 1955. Since then, some of the available on Sachensee water is in a 3.9-kilometer-long pressure tunnel to the hidden in the mountain water tower and from there to the two turbines of the power plant Obernach headed whose outlet opens into the Walchensee. A maximum of 25 m³ / s of water can be conducted into the Walchensee through the Isar overpass.
Rissbach transition
The Rissbach comes from the northern part of the Karwendel Mountains , where the water from the smaller streams flows in the area of the maple soils . Below the border between Tyrol and Bavaria and immediately after the confluence of the Fermersbach , the water-rich creek is dammed at the Oswaldhütte on the road Vorderriß (Bavaria) - Hinterriß (Tyrol) (838 m above sea level) and into the almost 7 km long Rißbach tunnel initiated. The Rißbach tunnel is divided into the 3,647 m long Grasberg tunnel, into which the water of the Fischbach flowing to the Rißbach is introduced about halfway . The Grasberg tunnel leads to a culvert with which the river bed of the Isar and the toll road running next to it is crossed above Vorderriß and just above Ochsensitz . The subsequent 3,313 m long Hochkopf tunnel ends above Niedernach at the Alpenbachwehr (821 m above sea level), with which its water is also directed into the Walchensee. A nearly 150 m long tunnel and an approx. 215 m long canal lead from the Alpenbach weir to the intake structure, from which the water is directed through a pressure pipe over a gradient of 21 m to the Niedernach run-of-river power station at the southeast end of Lake Walchen. Excess water runs from the intake structure over a wide canal staircase next to the power plant into the lake. A maximum of 12 m³ / s of water can flow into the Walchensee through the Rißbach overpass. The power plant has been in operation since 1951.
Technical operation
The Walchensee power plant gets its water from the inlet structure near Urfeld am Walchensee, which is largely hidden in the rock behind a road bridge and a rake . Via a 1,200 m long, 4.80 m high and 4.60 m wide concrete pressure tunnel , the floor of which is 10 m below the normal water level of the lake, the water flows through the Kesselberg into the moated castle, which is visible from afar, high above the power station . Its huge, 10,000 m³ water basin, 10 m deep, compensates for the pressure fluctuations in the pressure pipes that arise when the turbines are started up, controlled or switched off. In order to withstand the water pressure in the basin, its outer wall is designed like a dam wall with a thickness of up to 15 m increasing downwards. The water lock also contains the gate valves for the pipes leading to the power plant, including an overhead crane for maintenance and repair work , in an upstream valve house .
Six 430 meter long pressure pipes allow the water to flow to the eight turbines in the machine house. The diameter of the pipes decreases from initially 2.25 m at the top to 1.85 m at the bottom of the nacelle. The wall thickness of the tubes is 10 mm at the top and 27 mm at the bottom. The machine house, which is over 100 m long, is arranged to the side of the pipe track, so that it is not damaged by the falling water if a pipe breaks.
Four pipes each feed the head water to one of the four Francis turbines , while the other two pipes each supply two Pelton turbines with two impellers. The Francis turbines run at a speed of 500 min −1 , the Pelton turbines with 250 min −1 . All the turbines together can pass up to 84 m³ / s of water. From idle, the Francis turbines can be ramped up to full load in around 30 seconds; if the turbine is not completely filled, the process takes around three minutes. Below the turbines is the outlet, which flows into a canal into the Kochelsee.
The Francis turbines are connected to three-phase generators with a maximum output of 18 MVA and 6.6 kV each at a mains frequency of 50 Hz. The Pelton turbines are connected to single-phase generators , which are designed for generating traction current with the originally usual 16 2/3 Hz (which is tolerated by today's system with 16.7 Hz). The total output generated is divided into 72 MW three-phase current and 52 MW traction current. The standard work per year is approx. 300 million kWh. When the power plant was built, the orders for the generators were evenly distributed among the manufacturers at the time, so that four manufacturers each supplied two generators.
The electricity is fed from the generators to the transformer house across the courtyard, where the generator voltage of 6.6 kV is transformed to the mains voltage of 110 kV. The electricity is then fed into the overhead lines via the switchgear in front of the transformer house.
In the courtyard between the machine hall and the transformer house, a dismantled wheel set of a Pelton turbine with two running wheels (each with 22 screwed-on buckets) is installed on a shaft that weighs around 30 t. The wheel set was replaced because a further developed shape of the blades resulted in a higher degree of efficiency.
history
planning
The first plans to use the height difference of 200 m between Walchensee and Kochelsee to generate electrical energy go back to 1897. Oskar von Miller was the pioneer and planner for the construction of the Walchensee power plant. He wanted to advance the electrification of the Bavarian railway (see also Mittenwaldbahn ) and the state of Bavaria. Already in autumn 1903 - disguised as a search and rescue operation of a missing family - the underground of the Walchensee was examined by divers. At the same time, the first plans to build a full line Tölz – Lenggries – Jachenau – Mittenwald – state border became known. A connection with the planning of the power plant is obvious from today's perspective, as a replacement for the flow-wise removal of the wood from the mountains had to be created. A second and third project became known independently of one another in 1904. In the third, from the Prussian officer Fedor Maria von Donat , an Isar lake from Isar and Rissbach with a transition to Walchensee was already planned. The State Building Administration also submitted a draft in 1907. This led to great uncertainty among residents of the Isar, Walchen and Kochelsee lakes, who feared environmental pollution and destruction. In 1908 the state government announced a seven-month competition in which 31 designs were submitted. A first, second and third as well as three fourth prizes were selected from these; The first prize went to the project entitled “Simple and Safe”, which, with its relatively low water extraction, conserved nature as much as possible and at the same time was financially profitable due to its sufficient performance. This design was essentially implemented later. In the early summer of 1911, state construction management was set up in Kochel, although at that time there was still no state approval. At the 267th session of the Bavarian Chamber of Deputies on April 25, 1914, the Walchensee power plant was discussed in detail "as a matter of honor for the Bavarian people". However, the question was asked whether enough customers would be found for the electricity generated. Strangely enough, the Bavarian Ministry of Transport, in contrast to the Bavarian Ministry of the Interior, did not push the Walchensee project because they had doubts about the profitability of the electric railway. However, the aforementioned Oskar von Miller succeeded in convincing the cabinet, so that in early 1914 the Chamber of Deputies and in June 1914 also the Chamber of Reichsräte approved. Although the First World War broke out a few weeks later , von Miller continued - encouraged by King Ludwig III. who wanted to demonstrate Bavaria's capabilities - continued the plans that had been completed by the end of 1916. In 1917 so-called negotiation trips were made to the affected towns from Wallgau to Wolfratshausen .
After much preparatory work, the Bavarian state parliament decided on June 21, 1918 (five months before the end of the First World War) to build the power plant.
construction
| time | Number of workers |
|---|---|
| January 1919 | 120 |
| Early April 1919 | 300 |
| July 1919 | 500 |
| January 1920 | 800 |
| 1921 | 2000 |
| November 1923 | 2100 |
| December 1923 | 700 |
| February 1924 | 110 |
The construction work of the overall project, which is divided into three construction phases, began in Urfeld in November 1918. After only a few workers initially responded to a public call, their number grew over time from 120 to 2000 at the time of the highest company. These included numerous soldiers who returned home from war zones looking for work. Construction phase 1 included the measures from Krün to Walchensee: the Isar weir, the transition to the Sachensee and the expansion of the Obernach to Walchensee. This work was done by the Friedrich Buchner company from Würzburg . Around 100 people were employed here.
Construction phase 2 included the actual Walchensee power plant from the inlet in Urfeld to the Kochelsee. From December 9, 1918, the wool construction company from Leipzig took over the construction work on the inlet structure in Urfeld, the Kesselberg tunnel, the moated castle and the downpipe. The measures in the lower area, namely the construction of the power station and transformer house, the underwater canal and all access roads were carried out by the construction companies Eduards & Hummel and Alfred Kunz from Munich .
Construction phase 3 comprised the measures on the Loisach, in particular the Schönmühl hydropower plant and the Loisach-Isar Canal . The Bavarian construction company Kallenbach from Munich and the Upper Rhine construction industry from Freiburg worked .
The Kesselbach power station was specially built in the vicinity of the construction site to operate the numerous electrically powered construction machines . However, it could only cover around a third of the demand, the other two thirds were generated with locomobiles , i.e. with steam-powered generators. A total of 17 workers died during the construction of the Walchensee power plant, a memorial plaque on the power plant house.
The cost of the construction was estimated at 14 million marks before the First World War , at the end of 1919 it was already estimated at over 100 million marks. Because of the inflation, however, they were already 439 million marks in the spring of 1922, the final construction costs cannot be determined.
business
On January 5, 1921, the state-owned Walchenseewerk Aktiengesellschaft was founded in Munich, which was to continue and complete the construction and to take over the operation of the power plant. The also state owned Bayernwerk AG , founded on April 5, 1921, was supposed to take over the extensive distribution of the electricity. One turbine first fed energy into the power grid on January 24, 1924, the other seven turbines followed in the next few months.
The Bayernwerk was finally taken over by Walchenseewerk AG in 1942/43. In 1994 it was privatized and, in turn, taken over by VIAG , which in turn merged into E.ON in 2000, whose subsidiary E.ON Wasserkraft GmbH operated the power plant. As a result of various conversions , it became Uniper Kraftwerke GmbH in April 2015 .
The Walchensee power plant has been a protected industrial monument since 1983 .
particularities
The federal road 11 runs from Walchensee to Urfeld along the steep slope from the Herzogstand on the north bank. The water of the Walchensee exerts pressure on the shore, which prevents the road from slipping. If the water level falls in winter due to consumption by the Walchensee power plant, the use of the road is restricted by a weight restriction for trucks. At a suitable time in spring, the operator is obliged, under threat of a contractual penalty, to raise the water level so that the traffic restriction - mainly due to tourism - can be lifted. Therefore, the energy company informs itself about the snow conditions in the water catchment area in winter in order to be able to calculate how much melt water is likely to be available to meet the requirement.
At the beginning of the power plant operation, due to subsidence of up to more than five meters in the lake, for the above-mentioned reason, there were sometimes enormous bank breaks in many bank areas. In the spring of 1926, fortification measures were therefore started, especially around the place Walchensee in the bank area. In the period after the Second World War , when there was a general lack of electricity, there were landslides, for example in April 1955 when a considerable part of the B 11 sank in the lake.
In March 2015, the Jago submersible, stationed at the Helmholtz Center for Ocean Research in Kiel , entered the 1200-meter-long Kesselberg tunnel of the Walchensee power plant to document the state of construction.
tourism
In 2001, the then power plant operator E.ON Wasserkraft opened a new visitor center - the industrial monument is visited by almost 100,000 visitors every year.
The moated castle and a downpipe are illuminated at night.
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See also
literature
- Peter Schwarz: The construction history of the Walchensee power plant from 1918 to 1924 . Part 1. In: Heimatverband Lech-Isar-Land eV (Ed.): Lech-Isar-Land, Heimatkundliches Jahrbuch 2017 . Mohrenweiser, Weilheim 2016, p. 267-316 . Part 2 in: Heimatverband Lech-Isar-Land eV (Hrsg.): Lech-Isar-Land, Heimatkundliches Jahrbuch 2018 . Mohrenweiser, Weilheim 2017, pp. 231–270.
- E. Mattern: Wasserkraftanlagen in Bayern, II. In: Zentralblatt der Bauverwaltung , 43rd year 1923, No. 39/40 (from May 16, 1923) ( urn : nbn: de: kobv: 109-opus-56759 ), p 229-240.
Web links
- Walchenseekraftwerk on the Uniper website
- The Walchenseekraftwerk , publisher: Eon Kraftwerke GmbH, Landshut 09/2013, on Wasserkraft-ja-bitte.com (PDF 2.5 MB)
- Walchensee power plant on the website of Touristinfo Walchensee .
- Christian Holzhammer: Storage power plant Walchensee power plant ( Memento from May 22, 2007 in the Internet Archive ) - Illustrated seminar paper, 1999
- Anja Keim: The Walchensee Power Plant - History and Functionality ( Memento from March 12, 2006 in the Internet Archive ) (PDF; 110 kB) Presentation, 2003
- The "Baraber vom Walchensee", a historic share
- Walchensee power plant - where does the Isar water actually come from? on the Oberland website
Individual evidence
- ↑ a b Das Walchenseekraftwerk , publisher: Eon Kraftwerke GmbH, Landshut 09/2013, on Wasserkraft-ja-bitte.com (PDF 2.5 MB)
- ↑ a b c d e f Peter Schwarz: The building history of the Walchensee power plant - 1918 to 1924 . In: Heimatverband Lech-Isar-Land eV (Ed.): Lech-Isar-Land. Local history yearbook 2017 . Mohrenweiser, Weilheim 2016, p. 267-316 .
- ↑ a b Jost Gudelius: The Jachenau . Jachenau 2008, ISBN 978-3-939751-97-7 , p. 166 f.
- ↑ a b c d e f g Peter Schwarz: The building history of the Walchensee power plant - 1918 to 1924 (part 2) . In: Heimatverband Lech-Isar-Land eV (Ed.): Lech-Isar-Land. Local history yearbook 2018 . Mohrenweiser, Weilheim 2017, p. 231-270 .
- ↑ The Walchensee power plant . Uniper Kraftwerke GmbH brochure. Retrieved December 4, 2016 (PDF; 871 KB).
- ↑ Veronika Ahn-Tauchnitz: Mission Kesselberg-Stollen: With the diving boat through the tunnel. March 20, 2015, accessed August 5, 2016 .
Upper Isar: Krün | Sylvenstein | Stain | Bad Toelz | Mühltal (Mühltalkanal)
Walchensee / Loisach: Obernach | Niedernach | Walchensee | Schönmühl | Beuerberg | Eurasburg | Wolfratshausen
Isar-Werkkanal: Höllriegelskreuth | Pullach | Isarwerk 1 | Isarwerk 2 | Isarwerk 3 | Stadtbachstufe
Auer Mühlbach: Kraemer's art mill | Baker's mill | Muffatwerk | Maxwerk
Middle Isar: Prater | Tivoli (Eisbach) | Oberföhring | Ludwigswehr | Gerlmühle | Maxwehr
Middle Isar Canal: Ismaning | New insing | Church up | Eitting | Pfrombach | Uppenborn 1 + 2
Lower Isar: Altheim | Niederaichbach | Gummering | Dingolfing | Gottfrieding | Landau | Ettling | Softly