The addition of two new units to the Itaipu hydropower plant in Brazil in 2004 will be a watershed for the project. Building on its reputation for high availability and record-setting output, Itaipu will be able to continue its central role in the electricity markets of Brazil and Paraguay for many years to come.
In early 2001, work started on the construction of two new power generating units at the Itaipu hydropower plant on the border of Brazil and Paraguay. By mid 2004, these two new units will be operational, increasing the capacity of the plant by 1400 MW and cementing the importance of Itaipu to Brazil’s and Paraguay’s power systems.
The two new units will increase Itaipu’s capacity by 1400 MW by 2004
For nearly 20 years, the Itaipu hydropower plant has been generating electricity for both Brazil and Paraguay. Located on the Paranàƒ¡ River on the Brazil-Paraguay border, its output accounts for some 95 per cent of Paraguay’s electricity demand and roughly one-quarter of Brazil’s. According to its owner, Itaipu Binacional, every year the plant surpasses its own world record of electricity production.
The two new generator units at Itaipu will be installed at a cost of $184m
Itaipu’s outstanding operational performance is well documented: its indexes of availability, forced unavailability and the low failure rates of its generator units are international reference points. In 2000, it reached its highest production levels since becoming operational in 1984, generating
93 427 598 MWh of electricity ” a new world record and equivalent to 24 per cent of Brazil’s electricity demand. Production in 2001 fell 15 per cent due to the drought and electricity rationing programme in Brazil. Scheduled availability in 2000 reached 95.6 per cent.
Due to increasing electricity demand in both Brazil and Paraguay, Itaipu Binacional decided to install two additional generators at the Itaipu plant. The addition of these will increase the number of generating units to 20 and generating capacity of the plant from 12 600 MW to 14 000 MW. The first unit (9A) will be commissioned in January 2004, while the second (18A) will start up in May 2004.
Leading the way
With the two new units on-line, Itaipu will be able to generate enough electricity to supply a city of more than 3 million inhabitants. The additional units will also give Itaipu Binacional more operating flexibility; with the plant’s current 18 units, 16 units usually operate simultaneously. This occasionally rises to 17 units when needed. When expanded to 20 units, Itaipu Binacional will keep 18 units operating simultaneously.
Since the last of its 18 generating units was commissioned in 1991, Itaipu has been the largest hydropower plant in the world, and it will remain so until the
18 200 MW, Three Gorges hydropower plant in China becomes fully operational in 2009. However, Itaipu Binacional is keen to point out that in spite of having fewer units and a lower installed capacity than the Three Gorges project, the expanded Itaipu plant will, in theory, be able to generate more electricity than the Three Gorges plant.
The Three Gorges project is forecast to generate 84 TWh/year from its 26 installed units. However, Itaipu’s records show that for the last five years, generation has averaged 90 TWh/year. This, says Itaipu Binacional, could reach 95 TWh when the plant’s capacity is increased in 2004, and even 100 TWh if hydrological conditions permit. Brazil’s federal generating company, Eletrobras, has predicted that in ten years’ time, Itaipu will generate the equivalent of 16 per cent of Brazil’s electricity consumption.
On November 13 of 2000, then-president of Brazil, Fernando Henrique Cardoso, and that of Paraguay, Luis Gonzàƒ¡les Macchi, met in Itaipu for the signature of the contract for the installation of the two new units.
The two new generator units will be installed at a cost of $184 million. This compares to an installed cost of $1000 per MW for the original Itaipu power plant. The debt for this now rests entirely with Eletrobras, which receives payment in energy from Itaipu.
In mid-2000, Itaipu Binacional, the binational company formed by Brazil and Paraguay to operate Itaipu, awarded the contract to expand the capacity of the plant to an international consortium called Consorcio Empresarial Itaipu (CEItaipu). The $186 million contract involves the design, development, installation and commissioning of two complete hydroelectric power generating units, each with a rated output of 700 MW.
Alstom is the leader of the consortium, and is responsible for the general management and coordination of the project. The contract involves the execution of the project, the manufacture, in-factory trials and tests, packing, transport, storage, installation, electro-mechanical erection, the civil construction works, anti-corrosive treatment, trial for placement in service, commissioning and manuals for electromechanical erection, operation and maintenance.
Other companies involved in the project include Voith Siemens Hydro Power Generation, Siemens, Bardella, CIE and ABB, which are principally responsible for equipment manufacturing; Ivai, CESBE and Conempa, which are involved in the project’s civil construction works; UTC EBE and CIE, which are responsible for electro-mechanical erection; and Themag, Promon, Technipar and Inconpar (engineering).
Together with Voith Siemens and the other manufacturing companies, Alstom is responsible for manufacturing the two 700 MW turbines, the 750 MVA, 18 kV generators together with the turbine speed governor system and the supervision and control system. Voith points out that it supplied 50 per cent of the original equipment at Itaipu, and is again responsible for 50 per cent of the equipment supply part of the contract ” equivalent to 38 per cent of the total turnkey scope of the contract.
Given the successful operation of the existing 18 units installed at Itaipu, and for reasons of standardization, Itaipu Binacional decided that the new units should be of the same design as the existing ones. The new units will therefore be Francis units ” one 50 Hz unit and one 60 Hz unit ” but will include some technical improvements in terms of materials and components, such as a modernized supervisory control system.
Operation and maintenance at Itaipu is carried out by Itaipu Binacional, which will also carry out operation and maintenance of the two new units.
Itaipu: a world leader in hydropower
The first of Itaipu’s existing 18 generating units entered operation in May 1984; the last in April 1991. Construction of the vast project started in 1975 following the signing of the Treaty of Itaipu by Paraguay and Brazil, and the creation of Itaipu Binacional. Located on the Paranàƒ¡ River on the border of Brazil and Paraguay, the plant has for nearly 20 years played a key role in the electricity systems of both countries.
The plant consists of a 612 m-long, 196 m-high hollow gravity dam and a reservoir with a surface area of 1350 km2. The structure generates a rated head of just over 118 m as water flows through the powerhouse ” itself nearly 1 km in length. The powerhouse houses 18 Francis generating units ” 9 of 50 Hz and 9 of 60 Hz to accommodate the demands of the Paraguayan and Brazilian electricity systems respectively. Each turbine unit weighs over 3000 t.
Power from the plant is transmitted to both Paraguay and Brazil via high voltage transmission lines and substations on the right bank (Paraguay) and left bank (Brazil). Converter stations on the Brazilian side can transform the 50 Hz power not required by Paraguay into 60 Hz energy for use in Brazil.
According to Itaipu Binacional, the total volume of concrete used in the construction of Itaipu would be sufficient to build 210 football stadiums like the Maracanàƒ£ in Rio de Janeiro, Brazil, while the iron and steel employed would permit the building of 380 Eiffel Towers. In addition, the volume of earth and rock excavations at Itaipu is 8.5 times greater than that of the Eurotunnel linking France and England under the English Channel, and the volume of concrete is 15 times greater. Crucially, Brazil would have to burn 434 000 barrels of petroleum a day to obtain from thermoelectric plants the same amount of energy it obtains from Itaipu.