Peixe Angical Plant - 498.8 MW


Construction of the Peixe Angical hydroelectric power plant began in April 2002 and was interrupted for about a year before resuming in October 2003, after FURNAS joined the Enerpeixe Specific Purpose Company, currently made up of Energias do Brasil (EDP / Energias de Portugal Group), with a 60% share and FURNAS, with 40%, and total investment of R$ 1.6 billion.

Located on the Tocantins River in southern Tocantins, between the cities of Peixe, São Salvador do Tocantins and Paranã, the plant came online on September 16, 2006. The plant’s three turbines have a total installed capacity of 498.8 MW, generating guaranteed 2,374 GWh annually, enough to supply a city of about 4 million inhabitants, equivalent to double of Brasilia’s energy consumption. The energy is transferred to the Brazilian Electric System via a 500 kV transmission line through the FURNAS substation in Gurupi (TO).

To overcome the challenge of building a dam in a short period of time and in a region with high average temperatures, FURNAS developed specific thermal studies that highlighted the fact the concrete would have to be cooled with ice in order to reduce the structure’s maximum temperature, since the hotter the concrete gets, the higher its thermal shrinkage, which can lead to cracking. An ice factory capable of producing 10 tons of flake ice per hour was built on site. The ice was added into the concrete and water mixture.

The Peixe Angical dam has RCC (roller-compacted concrete) on the riverbed and on river banks, is 6.2 km long and 39 meters high, has a reservoir with a flooded area of 294 km² and an accumulated water volume of 2.7 billion m³. The plant also has a 213 meter spillway that can drain 37,044 m³/s. The project was concluded in record time and at its peak, employed over 5,000 people.

The environment was a major factor during each phase of construction. The project included 30 environmental programs related to the physical, biotic and socioeconomic environments, which accounted for 14% of the project’s overall investment. During the reservoir filling stage, teams of biologists, veterinarians and environmental technicians monitored possible environmental disruptions that could affect the lake, rescuing more than 55 thousand animals that were then identified, registered and transferred to other areas near their original habitat.


Technical Data


Dam

  • Dam: Roller-compacted concrete (RCC) on the riverbed
  • Maximum Height: 41.35 m
  • Total concrete volume: 893,439 m³
  • Soil dam: right and left banks with homogeneous segments with compacted embankments, vertical and horizontal sand filters and riprap
  • Maximum left bank height: 39 m
  • Maximum right bank height: 30.5 m
  • Volume of compacted soil/filter/riprap at the left bank: 6,217.066 m³
  • Volume of compacted soil/filter/riprap at the right bank: 884,164 m³


Reservoir

  • Maximum storage level: 263 m
  • Maximum flood level: 263.2 m
  • Minimum operating level: 261 m
  • Flooded area: 294.1 km²
  • Total volume: 2.74 billion m³
  • Usable volume: 528.3 billion m³


Water Intake

  • Gates: 9
  • Type: gravity
  • Water height on sill: 40.90 m
  • Width: 7.73 m
  • Height: 17.03 m
  • Manufacturers: Bardella


Spillway

  • Maximum Discharge: 37,044 m³/s
  • Gates: 9
  • Type: segment
  • Width: 17 m
  • Height: 23.18 m
  • Radius: 25 m
  • Manufacturers: Bardella


Powerhouse

  • Type: sheltered
  • Size: 98.1 m x 53.65 m
  • Generator units: 3
  • Rated capacity per unit: 153.12 MW
  • Total generating capacity: 498.8 MW


Turbines

  • Type: Kaplan
  • Kaplan rotor diameter: 8.6 m


Generators

  • Frequency: 60 Hz
  • Terminal voltage: 13.8 kV
  • Transformers: 3 (operating)
  • Type: three-phase
  • Total operating capacity: 1,525 MVA
  • Transformation ratio: 13.8/138 kV
  • Manufacturer: Siemens