Environmental impact of power generation: a review

The increasing worldwide concern about the planet health is reflected in the willing-to-pay behavior in face of environmentally sound products (the case of American unleaded gasoline) and also in the recently approved international standards as ISO-14000. Considering this, a comparison between major energy sources, like Hydro, Thermal and Nuclear electricity, strictly in terms of environmental impact, becomes relevant. this paper intends to trace a critical analysis of the actual environmental impact occurred in the last 20 years, comparing it with the imagined impact that was foreseen 20 years ago, and making some comments about the future. What one sees nowadays is quite a different situation as it was seen by the environmentalists in Brazil at that time (1976). The cost of land around rivers has increased significantly; social problem with flooding land is even critical in several areas; forests are given higher value than ever; the CO2 yield has become a world concern, as SOx and NOx as well; C H4 released from flooded forests is a powerful greenhouse gas; the safety of Nuclear Power Plants are still questioned, as well whether or not the uranium reserves are going to support an increasing demand for more 20 years; new standards in public acceptance of pollution has been established. A greater dose of rationale should be put into this discussion. (author)