The Estreito Hydroelectric Power Plant (Estreito UHE), an undertaking of the Consórcio Estreito Energia (Ceste) [Estreito Power Consortium] on the Tocantins River, on the border between the states of Tocantins and Maranhão, generates 1087 MW of power. At the peak of the construction work the investment generated approximately 11,000 direct jobs and 16,000 indirect jobs, a total of 27,000 jobs.

Alcoa has a 25.49% share in the Estreito Power Consortium. The other shareholders are Tractebel Energia (40.07%), Vale (30%) and Camargo Corrêa Energia S.A (4.44%). The use concession for exploring the power plant was acquired at an auction arranged by the National Electricity Agency (Aneel) on July 12, 2002, in the Rio de Janeiro Stock Exchange.

The development is following a timetable that is divided into three stages. The Zero Phase comprised the installation of the construction site, with lodgings for the workers, a canteen, a leisure area and offices. The construction work for the Estreito dam, which started in February 2007, is concentrated on a 1300 hectare site.

Phase 1, which has been finalized, covered the excavation and earth-moving services for construction of the coffer-dams and the spillway, which enabled concreting (Phase 2) to begin, which comprises construction of the actual dam and the power plant.

Phase 2, which is currently underway, includes the electro-mechanical assembly and commissioning of the turbines and the all of the power plant’s final installations. In April 2011, the first turbine started generating commercial electricity. All of the power plant’s installation construction work should be finished by September, 2012.rgia da primeira turbina. Até setembro de 2012 todas as obras de instalação da usina devem ser concluídas.

While work on the construction site was proceeding, properties situated in the area of the future reservoir of the Estreito power plant were being acquired, the local population was being resettled and infrastructure relocated. Among other demands this included the construction of bridges and the raising of existing ones, the relocation of power transmission lines, the building of roads and mooring points, as well as service aimed at tackling the various environmental variables.

Several public hearings were held between 2001 and 2004 at which the Estreito Project was presented and widely discussed in all the local communities in those municipalities surrounding the Estreito power plant and its reservoir. As a result, the public hearings indicated a series of improvements and elicited commitments that were incorporated into the Environmental Impact Study, resulting in the Preliminary License being granted in April 2005, a document that warrants the environmental viability of the project.

At the end of 2006, the Brazilian Institute of the Environment and Natural renewable Resources (Ibama), an agency linked to the Environment Ministry, approved the basic Environmental Project. This led to the Installation License being granted for construction of the Estreito power plant.

The reservoir filling process began on December 1, after Ibama granted the Operating License for the Estreito Hydroelectric Power Plant on December 24, 2010. In April 2011 the power plant began operating the first of its eight power turbines. The Estreito UHE should be fully operational by September 2012.

The electricity produced by the Estreito UHE will be incorporated into the North/Northeast and North/South/Southeast power transmission systems and can be distributed throughout Brazil to both industrial and residential consumers, including to those living in the region where the power plant is being built.

With the shareholding it also has in the Serra do Facão power plant in Goiás and with Estreito (in which it has a 25.49% shareholding) going operational, Alcoa will be 70% self-sufficient in energy in Brazil. This supplies the needs of the Poços de Caldas unit and part of the consumption of Alumar. The rest comes from a contract with Eletronorte.