Brauweiler substation
| Brauweiler substation | ||
|---|---|---|
 Entrance area of the Brauweiler substation |
||
| Data | ||
| place | Pulheim - Brauweiler | |
| Client | Rheinisch-Westfälisches Elektrizitätswerk | |
| Construction year | 1928 | |
| height | 57 m above sea level NN m | |
| Coordinates | 50 ° 58 '0.3 " N , 6 ° 48' 23.1" E | |
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| particularities | ||
| Control center system management networks , largest switchgear in the world at the time of construction, northern end point of the north-south line | ||
The Umspannanlage Brauweiler (also Umspannwerk Brauweiler or Station Brauweiler ) is a substation and switchgear in the Pulheim district of Brauweiler in the German state of North Rhine-Westphalia . The plant, built by RWE in the 1920s, served as the central load distributor in the transmission network and was the largest of its kind in the world when it was built. It played an important role in the development of the interconnected system between Alpine hydropower and Rhenish lignite ( north-south pipeline ), from which the German and pan-European power grid later developed.
The substation is still one of the largest in Germany today and is of national importance thanks to the network management system located on the site (formerly the main control center in Brauweiler ).
Location and connection
The substation is located in the area of the city of Pulheim , east of the Brauweiler district . The Cologne city center is around 10 km south-east. To the west of the switchgear are the main control center buildings in the southern part and the logistics center area in the northern part. A business park has been established around the facility.
There is a siding from the Rheydt – Cologne-Ehrenfeld railway line to transport the power transformers . A road connection leads in the western part of the complex via Von-Werth-Straße .
history
The construction of the Brauweiler substation is closely linked to the network development of RWE, which formed the basis of the plan to operate its own lignite power plants with their consumers in the Rhineland and hydropower plants in southern Germany and in the Alps in conjunction with one another. From this, a busbar developed first, which took its northern end in Brauweiler and took up the energy from the surrounding power plants, later Brauweiler then became the central control center of the further expanding transmission network.
Development of the RWE transmission network
The entry into the supraregional energy supply began for the Rheinisch-Westfälische Elektrizitätswerk (RWE), which was founded in 1898 and originally supplied the city of Essen via an electricity company , in 1905 with the acquisition of the Rhenish Berggeist lignite mine near Brühl . Since the lignite reserves there quickly ran out, a supply contract was concluded with the Roddergrube mine near Hürth in 1913, which guaranteed RWE the lignite from there. At the same time, Bernhard Goldenberg , Technical Director of RWE, developed a thermal power plant based on Georg Klingenberg's concept that generates energy from the lignite in the Roddergrube. The 1,914 put into operation Vorgebirgszentrale , 1920 in honor of the late 1917 Bernard Goldberg's in Gold Mine renamed, has been steadily expanded and was shortly after the First World War, the most powerful power plant in Europe.
The power plant was connected to consumers in the surrounding area via an overhead line network. To operate these lines, the experience gained with the test route between Lauchhammer and Riesa , which had been put into operation two years earlier, was used and operated with 110 kV voltage. In addition to the Erftwerk , an aluminum works near Grevenbroich that went into operation in 1917 , there were connections to other RWE plants, such as the Reisholz power plant . Since the golden mine had to be expanded again and again at short intervals due to the expansion of the area, the annual report of the RWE stated as early as 1912/13 that “it is right to build power stations with even greater capacities under favorable electricity generation conditions and with even larger supply areas by using higher transmission voltages than has been the norm up to now. "Finally," neighboring plants [...] must also come to an understanding [...] about the location of their power stations and the layout of their transmission systems, if not a lot of capital is to be wasted unnecessarily. "
The network topology corresponded to that of a star with the power plant switchgear as the central point, despite a few mesh connections between the more distant areas, which made it necessary to guarantee the power generation in the power plant. In fact, until the mid-1920s, all of the RWE's power plants were connected to one another via 110 kV lines, but they were only used to cover peak loads. The golden mine itself took care of the distribution of base and peak loads.
Expansion to the integrated network
The electricity distribution situation in the Rhineland sparked interest in coupling energy generation with lignite with other energy sources. This plan became concrete from 1923, when the RWE established the Elektrizitäts-Actien-Gesellschaft. W. Lahmeyer from Frankfurt am Main and managed it as a subsidiary. Numerous energy supply companies in southern Germany were connected to Lahmeyer AG.
In March 1923 Arthur Koepchen (technical director at RWE since 1917), Ernst Henke (legal director) and Bernhard Salomon (general director Lahmeyer AG) visited the hydropower plants of Lechwerke AG near Augsburg and the steam power plant of Kraftwerk Altwürttemberg AG (KAWAG), their surpluses each in Summer and winter were highest. Inspired by this, a line connection was initially designed between Augsburg and Heilbronn , later a continuation via Höchst am Main (facilities of the Lahmeyer subsidiary Mainkraftwerke ) to the Goldenbergwerk was planned.
With the entry of the Lahmeyer subsidiary Württembergische Collector Rails AG (WÜSAG) into the use of water power in the Austrian Vorarlberg in November 1923 and the establishment of the Vorarlberger Illwerke the following year, the final design was finally created, the busbar from Bludenz through Upper Swabia to the Stuttgart area and via the Rhine-Main area into the Rhineland .
Since it was feared that the 110 kV voltage previously used for the operation of an overhead line several hundred kilometers long would not be economical due to the transmission losses, a 40 km long test track was built in 1923 from Ronsdorf to Iserlohn - Genna and visited the Southern California Edison and the Pacific Gas and Electric , which has been operating lines at this voltage level since 1921. After the RWE board of directors was convinced of the feasibility of a transmission with higher voltage, concerns arose that this would not be sufficient for the 600 km long connection itself. Masts and lines were therefore designed - for the first time worldwide at that time - for operation with 380 kV.
Construction of the Brauweiler substation
Construction of the southern line from Bludenz to Brauweiler began in 1924, initially in the Rheinau - Kelsterbach - Koblenz - Neuenahr section , which was put into operation in 1926 for a test with 110 kV. The entire line was completed in stages by 1929. Despite the expansion for 380 kV, the line was only put into operation with 220 kV; a voltage increase was planned for a later date. The rest of the RWE transmission network was also designed for 220 kV at that time.
Instead of expanding the power station switchgear of the Golden Mine, the decision was made to build a completely new substation, which, in addition to the link between the pipeline network of the lignite power stations and the supraregional network, should also serve as the central switching point for the RWE network. The first expansion stage comprised 36 switchgear panels for 110 kV and was put into operation on October 28, 1928. At the same time, the southern line to Hoheneck near Stuttgart was in operation with 110 kV. The control room moved here from the Golden Mine was still housed in a makeshift barrack at that time, but was already able to regulate the operation of the 110 kV network.
The construction of the 220 kV switchgear, the control room and the administration building began in 1929. The control room, now known as the Brauweiler main control center , went into operation for the first time on October 12, 1929 with the 220 kV system. In January 1930, Brauweiler built a northern line with this voltage across Wesel to the Nike power station in Ibbenbüren , which was taken over by RWE in 1924. Among other things, the Rhine crossing at Voerde with its 138 m high masts belonged to it. With the overall commissioning of the southern pipeline to Bludenz on April 17, 1930, interconnected operation between the hydropower plants in Vorarlberg and in the southern Black Forest - RWE participated in the construction of the Schluchsee plant from 1928 onwards . The network system controlled from Brauweiler at that time comprised 4,300 km of three-phase power lines, 49 substations (12 of which had a 220 kV switchgear) and a total output of 1,140 MW power plants.
Since the Siemens-Schuckertwerke were commissioned with the technical equipment of all seven substations along the route during the construction of the south line and they carried this out according to a uniform switching scheme, the technical structure of the systems in Brauweiler basically corresponded to that of the other substations. The outdoor switchgear extended over an area of 40 ha, was 1 km long and 400 m wide. 40 switch panels and five busbars for 110 kV as well as 13 switch panels and three busbars for 220 kV, which were supplied by six 220 kV and 19 110 kV circuits, were now in operation. Between the two voltage levels, two 9 m high and 180 t heavy oil-cooled power transformers with an output of 60 MVA, which were manufactured in Berlin and transported by rail to Brauweiler, were used to convert. A third such transformer was installed in 1932 and served as a reserve.
For reactive power compensation in Brauweiler, as in the other RWE substations, six choke coils with an output of 6000 kVA were installed in order to prevent load drops in the 220 kV network. Since the Koepchenwerk , a hydropower plant on the Hengsteysee , was still under construction when the Brauweiler substation went into operation, it was assumed that there would also be an increase in output on the southern line, so phase shifters were installed. When the Koepchenwerk went into operation, the electricity generated there was fed into a ring-shaped 220 kV network, which, in addition to the northern line, included a connection from Ibbenbüren via Osnabrück , Paderborn and the Koepchenwerk back to Brauweiler. For this purpose, the Ronsdorf – Genna test route, built in 1923, was included, the route of which had been designed for a connection between Rhineland and Westphalia .
There were two lines with a total of four 220 kV circuits between the Goldenbergwerk and Brauweiler. In addition, the three 110 kV lines in the direction of Reisholz, Bergische and Erftwerk, which had existed since 1917, were looped into the switchgear.
A voltage of 5 or 25 kV could be stepped down from the system to supply the control room itself. A high-frequency telephone system was always connected to other substations, including those of other network operators, such as the Bayernwerk in Karlsfeld near Munich . The task of the main control center was now to control and evenly distribute the energy that was now generated in thermal power plants in the Rhineland, the Ruhr area , in Ibbenbüren and in Paderborn and fed into the 220 kV line ring. It also included the Koepchenwerk pumped storage power plant near Dortmund and the power plants in southern Germany and Austria connected via the southern pipeline. In addition to the Vorarlberg hydropower plants ( Vermuntwerk ) and the steps of the Schluchseewerke, the coal-fired power plants in Heilbronn, Mannheim , Höchst and Dettingen were among them . The largest high-voltage transmission network in the world at the time was controlled from Brauweiler.
Under its first director, Fritz Kretzschmar, 70 people were employed in the main control room in Brauweiler in 1931. RWE had thus become the largest employer in the community. Eight residential buildings with a total of 24 company apartments were built for part of the workforce directly on the factory premises.
Inspired by the interconnected operation of RWE, the electricity pioneer Oskar von Miller (initiator of the International Electrotechnical Exhibition in Munich in 1891 ) presented plans for an all-German high-voltage network with a ring topology in 1930. The entrepreneur Oskar Oliven even drafted a general plan for a pan-European 400 kV transmission network that would combine the hydropower plants in Scandinavia and the Alps with the coal-fired areas in northern France , Belgium , western Germany, Upper Silesia and southern Russia.
Due to the political conditions at the time, realization was considered impossible. In addition, the Aktiengesellschaft für Deutsche Elektrizitätswirtschaft (Aktiengesellschaft für Deutsche Elektrizitätswirtschaft) was founded in 1928 around Elektrowerke AG , Bayernwerk and PreussenElektra , which was followed in 1929 as a competing company by Westdeutsche Elektrizitätswirtschaft AG as a voluntary amalgamation around Vereinigte Elektrizitätswerke Westfalen , RWE, Badenwerk and some smaller West German supply companies.
Role of the facility in the Nazi era
With the seizure of power of the Nazis in 1933, the conditions for the German electricity industry changed rapidly - with the adopted on 13 December 1935 law to promote energy decentralized energy supply was also with regard to military aspects, regulated, at the same time under the supervision of the State ( Ministry of Economic Affairs ) posed. The power supply for companies considered to be important to the war effort (aluminum plant in Grevenbroich, nitrogen fertilizer plant in Knapsack ) led to an increased demand for electricity, which was compensated for in 1936 by another expansion of the golden mine and the acquisition of Niederrheinische Braunkohlewerke AG with the Frimmersdorf power plant . After the Essen - Karnap coal-fired power station went into operation in 1939 and the Schluchseewerke Witznau power station , the Rodundwerk and the Illwerke Obervermuntwerk until 1943 , electricity sales, regulated by the RWE's 220 kV network, increased significantly.
With the establishment of the Reichsstelle für die Elektrizitätswirtschaft (also known as Reichslastverteiler ), a central office was set up for the regulation of the entire German network beyond the energy suppliers. The main control Brauweiler became the kingdom dispatcher directly below the district dispatcher was responsible, the b for the energy District VI. If the amount of electricity available in the energy district was insufficient , shutdowns were carried out from Brauweiler - on the instructions of the Reichslastverteiler and the planning office of the Reich Minister for Armaments and War Production . From the spring of 1944, large parts of the German network were interconnected to provide additional energy coverage for the production plants, which resulted in two frequency blocks. In addition to a block in central and northern Germany (PreussenElektra, Elektrowerke AG), another block was managed from Brauweiler, which included the network area of RWE to the south as well as the United Electricity Works Westphalia (VEW), which is managed as energy district VI a .
After the outbreak of World War II , the Nazi regime attempted to transport electricity from the occupied countries of the Netherlands , Belgium , Luxembourg and France . Arthur Koepchen, who joined the NSDAP with the entire RWE board on May 1, 1933, submitted a plan on May 25, 1940 that regulated the connection of the Western European networks with that of the RWE. The electricity from these countries was to be integrated into the RWE network via Brauweiler. Initially, numerous lines were planned for removal (five between the Netherlands and Germany alone), but three connections were implemented in the 1940s:
- A 220 kV line from Jupille near Liège via Lutterade in South Limburg and the Zukunft power plant near Weisweiler to Brauweiler
- A 220 kV line from Landres in Lorraine to Brauweiler
- A 220 kV line from the Provinciale Geldersche Electriciteits-Maatschappij (PGEM) power plant in Nijmegen to Kleve
The 220 kV line from Jupille to Brauweiler was largely completed in autumn 1941, but did not go into operation until 1944 due to a lack of material due to the war. Originally intended to transport the Belgian and Dutch electricity production to Germany, the supply of German war production in Belgium and France was now managed from Brauweiler via this line. In addition, the Heimbach power plant in Weisweiler was connected via a 110 kV line.
Despite the destruction of numerous RWE power plants during the Allied air raids from summer 1943, most of the network remained in operation until the end of 1944. Bales of peat were stacked around the transformers in order to protect the Brauweiler substation from breakdowns caused by bomb fragments. Only when the fighting shifted further west were parts of the network destroyed. At the beginning of 1945 the US Army occupied the main control center, which reported on March 5, 1945:
“We have just been occupied by Allied troops. [...] The pipelines on the left bank of the Rhine are mostly on the ground. We no longer have any connection with the south. We are also separating from the area on the right bank of the Rhine. "
post war period
Shortly after the end of the war, most of the damage in the network was repaired and operations were managed from Brauweiler. As a reparation payment, initiated by the Allies, the transport of electricity from Brauweiler to Lutterade / Jupille was started in October 1945 and to Landres in March 1946. The latter was implemented using a provisional 220 kV line on wooden masts between Landres and Mettlach , from where a 220 kV line from the RWE has led to the Koblenz substation since 1928. The network operation between Brauweiler and Vorarlberg was able to continue in the summer of 1945 until the entire network was free of interruptions and makeshifts, it took until 1948.
In order to provide the power supply in the war-torn country, the central load distributor for electricity in Bad Homburg was founded in 1946 by the state governments in the British and French zones . This was responsible for the main load distributors, to which the main control center Brauweiler had been declared for the western network area. With the improved supply situation through the construction of new power plants, the central load distributor was dissolved in the 1950s.
With the founding of the Deutsche Verbundgesellschaft (DVG) in 1948, the UCPTE in 1951 and economic growth in Germany and other Western European countries, the amount of electricity to be provided increased. Numerous power plants in the Rhenish lignite mining district were newly built or expanded, so that some new 220 kV lines were built and it was soon feared that this voltage level would no longer be sufficient. A necessary increase in capacity in the power grid was carried out in 1952 on the north-south line, which was already dimensioned for higher voltages: a circuit between Brauweiler and Rheinau was increased to 300 kV by extending the insulator chains. For this, new transformers and switchgear panels had to be installed in Brauweiler and Rheinau.
At the same time, the DVG carried out first tests for a transmission with 380 kV voltage on a test site near Mannheim, especially since a line of this voltage level was already in operation in Sweden . The knowledge gained was used in particular by RWE for a planned high-voltage network above the voltage level currently in use. In order to be able to operate the power grid more clearly, it was decided not to expand the facility in Brauweiler, but to build a completely new substation. Under the working title Brauweiler II , a 380/220 kV system was built north-west of Brauweiler in Rheidt-Hüchelhoven by 1954 , which was later named after the nearby community of Rommerskirchen . From there to Hoheneck, Germany's first 380 kV line went into operation in 1957 , which also runs past Brauweiler. In 1955, the group control center south was set up in Hoheneck as a subordinate service to the main control center in Brauweiler. Further group switching lines were created in Essen, Uchtelfangen and Rommerskirchen.
Because of the larger amounts of electricity, plans were also made to build a new network control room in Brauweiler from 1953, which should serve exclusively to regulate the network, instead of the previous control room together with the switchgear control. The network control room, which was very modern at the time, went into service in 1955, was staffed by two engineers at all times and was able to establish connections with all power plants and substations in the RWE network at any time. From 1953 radio links existed between Brauweiler and Essen and later to Hoheneck , for which a radio tower was set up.
Since the pipeline network in Germany grew strongly up to the 1970s due to the addition of numerous power plants and the entry into nuclear power (growth fivefold from 1955 to 1970), a new, larger network control room was set up in Brauweiler from 1971 to 1975, which was electronic for the first time could be controlled. At that time, the RWE operated a network consisting of 8,450 km of circuits and 132 stations in the high voltage network. A total of 688 employees worked for the main control center in twelve departments.
Recent developments
The electronic network management was renewed for the first time in 1992. In the course of EU directives relating to the liberalization of the electricity market , the load distribution in Brauweiler was ended when they came into force in 1999; instead, the focus is on ensuring trouble-free electricity transport by the network operator, since the network, which was previously operated by a single company, is now open to many electricity suppliers .
Since October 1, 2000, the main control center in Brauweiler has been under RWE Net AG , which was created through the merger of RWE with VEW. In the course of this, it was renamed System Management Networks . After the restructuring of the RWE Group in October 2003, the transmission network of RWE Net AG is now owned by RWE Transportnetz GmbH, which has been called Amprion since September 1, 2009 .
technology
technical structure
Today's substation consists of a 220 kV and a 110 kV switchgear, which is designed as an open-air station. Two transformers span between the two voltage levels. There are three busbars in the 220 kV system and four busbars in the 110 kV system. In the southern area of the system there is a radio tower for radio link connections. With an area of around 40 hectares, the substation is one of the largest in Germany.
At the beginning of the 2000s, the 110 kV system section was reduced by around half. Smaller parts of the 220 kV system have also been dismantled.
Overhead lines
All circuits leading to the substation are designed as overhead lines . The table below lists all the compounds that exist from Brauweiler. Lines that no longer exist today are marked in italics .
| Network operator | Route | Voltage, circuit name |
Destination / station | Year of construction of the route |
Dismantling | Cardinal direction |
Remarks |
|---|---|---|---|---|---|---|---|
 Amprion |
P. 2305 | 220 kV Pulheim Süd | Opladen | 1930 | North | ||
| F. 2357 | 220 kV Niederaussem 4d | Niederaussem power plant | 1930 | since 2017 | Previously continuous to Wesel , masts are being replaced by 380 kV | ||
| F. 2385 | 220 kV Niederaussem 1a | 1960s | |||||
| 220 kV Niederaussem 2b | |||||||
| 220 kV Niederaussem 3c | |||||||
| 220 kV Rommerskirchen Ost | Rommerskirchen | ||||||
| P. 2321 | 220 kV Fortuna Nord | Fortuna power plant | 1950s | today carries 110 kV systems | |||
| 220 kV Fortuna South | |||||||
| 220 kV future north | Future / Weisweiler | 1941 | 2003 | to Oberaussem replaced by a parallel line, previously via Weisweiler to Jupille (B) | |||
| 220 kV future south | |||||||
 RWE Deutschland AG ( Westnetz ) |
P. 2321 | 110 kV Grefrath Ost | Oberaußem → Ichendorf → Wachtberg Briquettes → Frechen | 1950s | System isolated for 220 kV | ||
| 110 kV Glesch South | Oberaussem → Paffendorf | ||||||
| Page 2483 | 110 kV Dormagen West | Dormagen | 1960s | System for 220 kV insulated, underground cable section on station premises (the line used to lead into the 220 kV system) | |||
| 110 kV Dormagen East | |||||||
| Page 0006 | 2 × 110 kV | Osterath | 1917 | 1970s | largely replaced by a parallel 380/220/110 kV line | ||
| Page 0012 | 2 × 110 kV | Reisholz power plant | 1914 | Last section of the Rhine overhead line crossing Reisholz dismantled in 2016 | |||
| F. 1064 | 110 kV Gohr West | Pulheim → Anstel → Gohrpunkt | 1950s | since 2017 | Masts will be replaced by 380 kV | ||
| 110 kV Gohr Ost | |||||||
|
Amprion |
P. 2351 | 220 kV Troisdorf West | Siegburg | 1928 | south | Between Brauweiler and Knapsack today 110 kV, from Frechen via Goldenbergwerk to Siegburg built in the 1950s | |
| 220 kV Troisdorf Ost | |||||||
| Bl. 4501 | 220 kV Olefin West | Bollenacker → Sechtem | 1929 | planned | North-south line , has been replaced in sections by a 380 kV line since 2018, before being integrated into the Sechtem substation, 220 kV Berggeist West and 220 kV Berggeist East | ||
| 220 kV Godorf Ost | |||||||
| P. 4511 | 220 kV Godorf West | Real | 1957 | System for 380 kV insulated, runs on the oldest 380 kV line in Germany | |||
| 220 kV Golden Mine West | Golden mine | 1928 | around 1990 | replaced by a 380 kV line | |||
| 220 kV Olefin Nord | |||||||
| Page 2416 | 220 kV Bocklemünd North | Bocklemünd | 1960s | ||||
| 220 kV Bocklemünd Süd | |||||||
|
RWE Deutschland AG ( Westnetz ) |
P. 2351 | 110 kV Gleuel West | Kalscheuren → Knapsack | 1928 | planned | System for 220 kV insulated, same masts as north-south line | |
| 110 kV Gleuel East | |||||||
| 2 × 110 kV | Golden mine | 1914 | around 1990 | replaced by a 380 kV line | |||
| 2 × 110 kV | 1917 | ||||||
| 2 × 110 kV | 1917 | ||||||
| Page 0082 | 110 kV Frechen West | Cheeky | 1941 | originally through to the United Ville mine , this line still exists for almost its entire length | |||
| 110 kV Frechen Ost |
System management networks
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Amprion's network system management is located on the area of the Brauweiler substation . Large parts of the German extra-high voltage network are remotely monitored and remotely switched from it, and the network operation of the power supply, i.e. the cooperation between the individual transmission system operators, is coordinated and balanced for the whole of Germany and the northern part of the European electricity transmission network at the voltage levels 380 kV and 220 kV (see UCTE ). . This includes the power grids of Belgium, Bulgaria, Germany, the Netherlands, Austria, Poland, Romania, Slovakia, the Czech Republic and Hungary.
To achieve this, Amprion and RWE also use microwave links . Therefore, on the area of the Brauweiler substation (as with all large substations) there is a radio relay tower designed as a free-standing steel framework construction.
The RWE logistics center is also located on the site.
literature
- Theo Horstmann and Klaus Kleinekorte: Electricity for Europe. Klartextverlag Essen 2003, ISBN 3-89861-255-4
Web links
Individual evidence
- ^ Hürth - Goldenberg-Werk. In: rheinische-industriekultur.de. Retrieved September 17, 2018 .
- ↑ T. Horstmann, K. Kleinekorte: electricity for Europe - 75 years RWE main control Brauweiler 1928-2003 . Klartext-Verlag, Essen 2003, p. 16.
- ↑ T. Horstmann, K. Kleinekorte: electricity for Europe - 75 years RWE main control Brauweiler 1928-2003 . Klartext-Verlag, Essen 2003, p. 35
- ↑ T. Horstmann, K. Kleinekorte: electricity for Europe - 75 years RWE main control Brauweiler 1928-2003 . Klartext-Verlag, Essen 2003, p. 50
- ↑ T. Horstmann, K. Kleinekorte: electricity for Europe - 75 years RWE main control Brauweiler 1928-2003 . Klartext-Verlag, Essen 2003, p. 57f
- ↑ T. Horstmann, K. Kleinekorte: electricity for Europe - 75 years RWE main control Brauweiler 1928-2003 . Klartext-Verlag, Essen 2003, p. 59f
- ↑ a b Arjen W. Kuiken: HOOGSPANNINGSLIJN NIJMEGEN-Kleef 1940-1944. Retrieved September 19, 2018 .
- ↑ Technische Universiteit Eindhoven: Electrifying Europe, p. 118. Retrieved on March 11, 2017 .
- ↑ T. Horstmann, K. Kleinekorte: electricity for Europe - 75 years RWE main control Brauweiler 1928-2003 . Klartext-Verlag, Essen 2003, pp. 60–62
- ^ H. Kirchhoff: Company form and sales policy of the power supply . Published by Julius Springer, Berlin 1933, p. 131
- ↑ T. Horstmann, K. Kleinekorte: electricity for Europe - 75 years RWE main control Brauweiler 1928-2003 . Klartext-Verlag, Essen 2003, p. 63
- ↑ T. Horstmann, K. Kleinekorte: electricity for Europe - 75 years RWE main control Brauweiler 1928-2003 . Klartext-Verlag, Essen 2003, p. 65ff
- ↑ T. Horstmann, K. Kleinekorte: electricity for Europe - 75 years RWE main control Brauweiler 1928-2003 . Klartext-Verlag, Essen 2003, p. 73
- ↑ T. Horstmann, K. Kleinekorte: electricity for Europe - 75 years RWE main control Brauweiler 1928-2003 . Klartext-Verlag, Essen 2003, p. 85
- ↑ T. Horstmann, K. Kleinekorte: electricity for Europe - 75 years RWE main control Brauweiler 1928-2003 . Klartext-Verlag, Essen 2003, pp. 95ff
- ↑ T. Horstmann, K. Kleinekorte: electricity for Europe - 75 years RWE main control Brauweiler 1928-2003 . Klartext-Verlag, Essen 2003, p. 101