Itaipú

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Itaipu Binacional
Dam wall with hydroelectric power station
Dam wall with hydroelectric power station
Location: Paraguay and Brazil
Tributaries: Paraná
Drain: Paraná
Itaipu Binacional (Brazil)
Itaipu Binacional
Coordinates 25 ° 24 '26 "  S , 54 ° 35' 20"  W Coordinates: 25 ° 24 '26 "  S , 54 ° 35' 20"  W
Data on the structure
Construction time: 1975-1982
Height of the barrier structure : 196 m
Building volume: 12.57 million m³
Crown length: 7760 m
Power plant output: 20 × 700 = 14,000 MW
Data on the reservoir
Water surface 1350 km²dep1
Reservoir length 170 kmdep1
Reservoir width 7-12 kmdep1
Storage space 29,000 million m³
Design flood : 62,200 m³ / s
logo

Itaipu ( Guaraní Itá 'rock', 'stone'; i 'the', 'which', pú 'sounds', coll. 'Sings'; Spanish Itaipú ; also Itaipu Binacional because of the participation of two nations) is the name of a hydroelectric power station and the associated Itaipu dam and the Itaipu reservoir at Paraná on the border between Paraguay and Brazil .

Until the completion of the Three Gorges Dam in the People's Republic of China in 2006, Itaipu was the largest power plant on earth in terms of output . Due to the high utilization of the turbines , Itaipu usually remains in first place in terms of annual energy production even after 2006.

Construction work

Construction work on one of the downspouts

The power plant is a joint project of Paraguay and Brazil, which was contractually fixed on April 26, 1973 by the then President of Brazil, Emílio Garrastazu Médici , and Paraguay, Alfredo Stroessner , in Brasília . Construction began in 1974 and was completed in 1982 (structure) and 1991 (18th turbine). Around 34,000 workers were employed on the large construction site. Since May 1984, two to three of the turbines have been connected to the grid every year until completion . In 2007, the Brazilian President Luiz Inácio Lula da Silva announced the completion of the project in a ceremony after the expansion by two turbines. 145 people were killed during the construction work.

power

By 2004, the nominal output of the total of 18 Francis turbines was 12,600  megawatts . From the beginning of 2004 the plant was expanded by two turbines; the total capacity of the power plant since the end of October 2005 is 14,000 megawatts. The two additional turbines, supplied and installed by Voith Hydro from Heidenheim , primarily serve to keep the amount of energy generated constant when other turbines are shut down for maintenance work.

The standard work capacity with a water flow of an average of 10,500 m 3 / s is 95  terawatt hours per year, which corresponds to an average of 10,800 megawatts. The stator diameter of the synchronous generators is 16 meters. In 2008, with a yield of 94.68 terawatt hours, the highest real generation of a hydropower plant worldwide was achieved. In 2012 it was already 98.287 terawatt hours. In 2013, a new record was reached with 98.63 terawatt hours. In 2013, Itaipu covered 75 percent of Paraguay's electricity needs, and Brazil 's 16.9 percent. Since commissioning in 1984 and up to and including 2013, Itaipu has generated 2,135 terawatt hours of electricity. In 2016, a new record was set for the generation of electrical energy with just over 103 terawatt hours.

At full capacity, two of the 20 turbines already have almost the same water flow as the imposing Iguazú waterfalls nearby , at 700 m 3 / s each .

For comparison, Isar 2 delivered 12.40 terawatt hours in 2006, as the nuclear reactor with the highest annual production worldwide.

use

Central control room

The generators located on the Paraguayan side generate three-phase current with a frequency of 50  Hz . The Brazilian network works with 60 Hz. Since the majority of the electrical energy generated in Paraguay is exported to Brazil, the electricity from Paraguay is first converted into direct current and then transported 850 km to São Paulo via a high-voltage direct current transmission (HVDC) where it is converted to 60 Hz.

For Brazil, which financed the entire facility in accordance with the contract, the construction led to a significantly higher level of foreign debt. However, Brazil, which received around a quarter of its electricity consumption from Itaipú after commissioning, is dependent on the power plant. Paraguay could not have financed and organized this huge project itself. Due to the country's increased electricity consumption (approx. 6.8 billion kWh in 2010 according to the CIA Factbook), the proportion is now only around one sixth. Paraguay pays its share of the construction costs by exporting the unneeded electricity to Brazil so that the country can use the income to pay off its debts. A part of the financial surpluses of the power plant is given to the neighboring communities on both sides of the border as compensation for the use of the Paraná .

Construction costs

There are various specifications for the construction costs, e.g. B. $ 19.6 billion or up to $ 60 billion. They are stated by the operator Itaipu Binacional as follows: USD 11.9 billion (direct investments without financing costs), USD 17.4 billion (fixed assets in the 2014 balance sheet) and USD 27 billion (loans taken out including rescheduling).

Workforce

In 2016, 3,038 people were employed at the dam, 1,371 on the Brazilian side and 1,667 on the Paraguayan side.

Reservoir and dam wall

View of the dam towards Brazil
Close-up of the downspouts; the bus conveys the standard

At normal storage height, the Paraná in the Itaipu reservoir is dammed over an area of ​​1,350 km² and a length of around 170 km. With its maximum storage volume of around 29 billion  m³ , its area even reaches 1,460 km². This makes the lake two and a half times the size of Lake Constance . The associated dam - the Itaipu dam - is 7,760 m long and 196 m high.

Further downstream in the south of Paraguay, on the border with Argentina , there is another huge hydropower plant on Paraná called Yacyretá with a capacity of 4,000 megawatts , which was pre-financed by Argentina according to a similar pattern as an Argentine-Paraguayan joint venture.

consequences

Particularly with a view to changing the environment, the costs and benefits of the dam are still controversial today:

There are also negative aspects to clean energy generation through hydropower . Even if the relation between the intervention in nature and the benefit due to the amount of energy produced at Itaipu is more favorable compared to other hydropower plants, its construction has changed the environment. Several thousand indigenous people lost their home, a total of around 40,000 people - mainly Guarani Indians - had to be resettled. For the construction of the dam , subtropical rainforest was cut down, areas of the rainforest in the area of ​​the reservoir, as well as the Sete Quedas waterfalls near Guaíra , were permanently flooded.

Visits

On the Brazilian side there is a visitor center on the edge of Foz do Iguaçu , in which an information film about the construction and operation of the plant is shown and from which bus tours to the power plant start several times a day. On the Paraguayan side there is a comparable visitor center at Hernandarias north of Ciudad del Este. There are tours or guided tours with different scope and focus. From the Paraguayan side the visits are free, on the Brazilian side an entrance fee has to be paid.

On Fridays and Saturdays, a light show accompanied by music is organized in which the dam is illuminated with 519 spotlights. A total output of 1 MW (light and music) is  used for this. A shuttle bus service will take place from both sides for this event.

During the construction phase, architects, engineers and students had the opportunity to visit the inside of the structure and the turbines.

Since 2005, “technical” tours have also been offered on the Brazilian side, during which tourists can visit the inside of the dam and the turbines.

Philip Glass , one of the most famous contemporary American composers, wrote the work "Itaipu" in 1989 after visiting the dam .

Technical specifications

Generator hall
  • Type of construction: hollow gravity dam (in the area of ​​the former river bed), massive gravity dam (in the area of ​​the former diversion canal), pier dam (adjoining the central part on both sides), rock embankment and earth embankment dam
  • Construction period: 1975 to 1982 (connection of the first turbines; the last turbines were put into operation in 2005)
  • Crown length (dam and wall): 7,760 m
  • Height of the dam wall: 196 m
  • Highest congestion destination : 190 m
  • Normal water level: 100 m (deepest point)
  • Storage capacity for floods: 29,000,000 m³
  • Total storage space : 29 billion m³ (for comparison: Lake Constance : 48.5 billion m³)
  • Water surface: minimum 1,305 km²; normal 1,350 km²; maximum 1,460 km² (for comparison: Lake Constance : 539 km²)
  • Reservoir length: 170 km
  • HWE rated water volume: 62,200 m³ / s (HWE = flood relief )
  • Nominal output : 12,600 megawatts (until 2004); 14,000 megawatts (since the end of 2005)
  • Generators used: salient pole generators with 824 MVA each
  • Turbine used: Francis turbine
  • Standard energy capacity : 95 terawatt hours per year
  • Reservoir width: 7–12 km
  • People to be relocated: 40,000 people

Build volume:

  • Removal of earth and rocks: 63.85 million m³
  • Filling of earth and rocks: 15 million m³
  • Concrete: 12.57 million m³

(Details: Itaipu Binacional)

Power lines

Electricity is transported to the greater São Paulo area via 765 kV high-voltage lines (for generation on the Brazilian side) and two bipolar 600-kV high-voltage direct current transmissions with a length of 785 and 805 kilometers (for the electricity generated on the Paraguayan side ). An HVDC solution was necessary because the generators on the Paraguayan side deliver three-phase alternating current at 50 Hz, while Brazil requires 60 Hz. The converter stations are located in Foz do Iguaçu and in Sao Roque near São Paulo, Brazil.

See also

Web links

Commons : Itaipú  - collection of images, videos and audio files

Individual evidence

  1. ↑ Record power production - Itaipu surpasses competition , n-tv.de report, Jan. 3, 2009 , accessed on March 27, 2010
  2. ↑ Blackboard in the power plant, seen on May 30, 2013 and information on itaipu.gov.py annual energy production
  3. ↑ “Consumption increases and Itaipu beats 2012 record”, message from Itaipu Binacional, Jan. 8, 2014 , accessed on February 9, 2014
  4. ^ Itaipu Hydroelectric Dam, Brazil. Power Technology, accessed July 28, 2016 .
  5. ↑ Itaipú terminará costando más de US $ 60,000 million. www.abc.com.py, April 19, 2013, accessed July 28, 2016 (Spanish).
  6. ↑ FAQ. www.itaipu.gov.br, accessed on July 28, 2016 (English).
  7. ↑ Itaipu Binacional: Number of employees , notification from December 2016, accessed on February 17, 2017
  8. ^ Hans Tanner: South America. Westermann Verlag 1980. Volume 2, p. 95.
  9. ↑ Official website