Although the generation of hidroeltrica energy is classified with renewable energy, the plant construction hydroelectric plants leads great ambient liabilities, as for example, flooding of great areas, promoting alterations in ecosystems of the regions. An example is the plant hydroelectric plant of Tucuru, installed in the Amazonian forest with area of 2.430 km flooded, that it can compromise local biodiversity, extinguish some species, deprive of characteristics some communities quilombolas and aboriginal reserves. The elio-electric generation became enlarged in the world of form sped up throughout the last decade, reaching the scale of gigawatts. One of the factors that limit investments in aeolian enterprises has been the lack of consistent and trustworthy data. The majority of the available anemometric registers is masked for aerodynamic influences of obstacles, rugosidade and relief. The availability of representative data is important in the Brazilian case, that still it did not explore this abundant and renewable resource of expressive form. In function of the ambient impact brought by the conventional sources of generation of electric energy, one has searched to stimulate, the world-wide level, the use of sources you renewed of energy.
In the Brazilian energy matrix, one strong participation of the use of the energy generated for the great hydroelectric plants is observed that, although to be considered as sources you renewed of energy, need the overflow of vast areas, many times of native forests, for water storage. The alternative sources, as of the generation of aeolian energy, still little are used, although the great potential of maritime winds in Brazil, mainly in the coast of the State of the Rio Grande Do Sul, where if it intends to implant a unit of generation of energy with the use of this potential, more necessarily, in the Lagoon of the Ducks. An important geographic complementaridade between the potentials aeolian and hydraulical in Brazil: in general way, the best ones areas for aeolian exploitation place in the extremities of the electrical system, distant of the generation hydroelectric plant. In this situation, the insertion of aeolian energy in the electrical system improvement its performance, diminishing transmission lines. Investments in the order of R$ 200 MI, gifts in this study, considered high, require based economic feasibility studies in necessary information, with details of the initial investments, markets, processes of manufacture, place of implantation, forms of financings, costs of production, hand of workmanship, maintenance and taxation. These aspects had been analyzed in the present work and were concluded favorably to the implantation of the unit, which is sustainable economically. 1.2. OBJECTIVES This work has for purpose to carry through the evaluation of the economic viability of the implantation of a unit of generation of electric energy proceeding from the existing aeolian energy in the Lagoon of the Ducks, in state of the Rio Grande Do Sul.