|Fig. 1: Itaipu Dam. (Source: Wikimedia Commons).|
Hydroelectric power plants (like the Itaipu Dam shown in Fig. 1, the second largest hydroelectric power station in the world) produce around 80% of the electrical energy consumed in Brazil. In 2013, over 40% of all primary energy produced in Brazil came from renewable resources, a figure that is very significant when compared to the world average of about 13%. 16.5% of Brazil's renewable sources come from sugarcane products, 12.5% from hydropower and 8.3% from other biomass.  Solar, wind, and other renewable resources still play a role in energy production, making up a little under 5% of the total primary energy produced in Brazil. 
Brazil has the third highest potential for hydroelectricity, following China and Russia. Currently the major source of electricity production in the country, hydropower is projected to remain crucial in meeting the nations electricity demands over the coming decades. 
Hydropower is an attractive way to source power for multiple reasons. Primarily, this method of energy production is cheaper than thermoelectric power, along with most other renewable forms of electricity. Hydropower can also provide energy at scale with greater feasibility and fewer disruptions than solar or wind power. In addition, hydropower has the potential of providing electric energy with lower levels of greenhouse gas emissions than thermoelectric energy. 
Energy consumption in developing countries is projected to increase 69% (from 2010) by 2030, and account for 65% of total consumption around the world, compared to 54% in 2010 (an increase of 11%). In order to meet the growing demand for electricity in upcoming years, Brazilian authorities are expanding hydropower generation in the Amazon, with plans to implement a large number of hydroelectric plants in that area. The new plants to be built by 2022 are said to generate 32.882 MW. 
Following the energy crisis the nation faced in 2001, which resulted in severe rationing, Brazil's energy production has increased from 330.4 TW h to 513.3 TW h between 2001 and 2012. In order to prevent a crisis like the one in 2001, Brazilian policy makers have devised mechanisms to generate adequate power supply, including establishing target levels for reservoirs, and devising risk-aversion and impact-minimization strategies.  This, in turn, has sparked the nations ambitious expansion goals in terms of hydropower.
As with any energy source currently available, hydropower comes with significant social and ecological costs. Reservoir establishment, usually implies dam construction and flooding, which have the potential of negatively affecting the lives of local residents by resulting in displacement, forced migration, and the destruction of and ancestral lands.  Hydropower dams can severely impact river ecosystems and lead to the flooding of adjacent terrestrial ecosystems, outbreak of diseases among the inhabitants and result in an influx of laborers who are left seeking for jobs upon the completion of the dams.  Not only do hydropower plants have the potential of affecting local communities, but they can also have severe effects on wildlife and fish populations. Dams are usually built in areas that can boost hydropower potential, areas with rapids, waterfalls and fast-moving waters. Unfortunately, these high-gradient waters are home to many unique fish populations.  Thus, the construction of large dams will invariably decimate fish populations, blocking movements that connect populations and enable migratory species to complete their life cycles. This can be particularly damaging for fisheries in tropical rivers, where many highly-priced species partake in lengthy migrations. 
Balancing energy supply and economic growth while still prioritizing environmental protection has become a major challenge for Brazilian authorities. Officials must concern themselves with the effective and conscientious planning of their electric sectors, keeping energy security requirements, economic growth projections and climate change impacts in mind when making such decisions. 
Policies that include integrated approaches to energy growth and supply, land use, and environmental safekeeping are needed to minimize the costs associated with the implementation of hydroelectric power plants and other major infrastructures that pose threats to the surrounding tropical ecosystems.
© Camila Camacho. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
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