The greatest medium-term answer to Brazil’s energy crisis lies in Tucuruí, in Pará, says the sector’s technocracy. With such emphasis that the work to double the hydroelectric plant’s capacity has been accelerated to the maximum. By the end of next year, the first of the 11 new turbines (12 have already been installed) could start generating enough to supply a market equivalent to half of Pará, which has six million inhabitants. A new machine would be commissioned every three months.
At the end of the complete motorization, the plant would have added 4.2 million kilowatts to its current power, or 8% of national energy consumption. When completed in 2004, Tucuruí’s installed capacity would jump to more than 8 million kW, just a little below the 12 million kW of Itaipu, the binational power plant of which only half is Brazilian. The other half is Paraguayan.
The investment needed to double the hydroelectric plant’s engine room is not small, in nominal terms: 1.4 billion reais. But in terms of the R$/kw ratio, the proportional value is insignificant. A new plant with a capacity of 4.2 million kw would, at best, require four times that amount. And it couldn’t come into operation in less than twice the time. The duplication of Tucuruí would be a manna from heaven in the country’s lean times.
In theory, yes. When it comes to checking, not so much. Technocrats fill their mouths and inflate their lungs to emphasize the 4.2 million kW that will be added to the 4.1 million that Tucuruí already produces. They fail to highlight one circumstance: only four of the plant’s 11 additional machines could operate at full load during the Tocantins River’s dry season. The other seven turbines would lack water. Between the possible record in winter and the maximum decrease in summer, the flow of the Tocantins could decrease 60 times.
In order not to be victimized by such depletion, the huge hydroelectric plant needs to accumulate as much water as possible in the six-month period of heaviest rainfall, using it as a reserve when the machines start demanding much more water than the amount reaching the reservoir. Generating at full load, the plant currently swallows six million liters of water per second. With the 11 new machines, which demand a little more water, this need will be 12.5 million liters per second – or 2.5 billion liters per minute.
The hydroelectric plant’s reservoir stores 55 trillion liters in an area of 2,850 square kilometers, later revised to 3,100 km2, which constitutes the second largest artificial lake in the country. With the pressure of energy consumption, Eletronorte decided to raise the maximum operational level of the reservoir by another two meters, which was at 72 meters. The impact of this measure is being assessed before it can be implemented, but the increase in generation will only be 110,000 kW, less than 3% of the plant’s production capacity.
The contrast between a water reservoir that has reached its peak and the doubling of its use for power generation explains the difference between the plant’s nominal power and its firm power. While it can generate 4.1 million kW today, Tucuruí only guarantees an average of 2.1 million during the Tocantins dry season, a “capacity factor” of 50%. This difference makes it difficult to convince the people of Pará that, during the critical rainy season, the hydroelectric plant will have to receive additional supplies from the Northeast to meet the needs of its customers.
The situation will get worse with the expansion of the plant: of the new 4.2 million kw that it will be able to generate at the peak of the rains, the firm capacity will drop to a mere 1.1 million kw at the height of the summer. So, while Tucuruí will have machines to produce a total of 8.3 million kw, in the dry season it will only be able to generate 3.3 million. The capacity factor will be well below the minimum international standard of 50%.
What is the solution to this problem? Increase the supply of water from the river. Naturally, this solution is beyond the possibilities of the Tucuruí reservoir, whose new maximum operating level will coincide with the crest of the dam, at just over 74 meters. A little more water, after the two-meter rise to be completed later this year, and the Tocantins would cover the dam.
Of course, this is not a hypothesis to consider. It would be a disaster. The only alternative would be to dam the river further upstream, using dams built for the simple purpose of regularization. A joint operation would make it possible to hold back more water and supplement Tucuruí’s shortfall.
But would it be plausible to build huge, expensive dams without adding power generation machines? Especially with the privatization of the energy sector, this is as implausible a hypothesis as the growth of the hydroelectric reservoir. Tucuruí will only reach a mature economic size if one or more dams are built upstream, either the Tocantins itself or its main tributary, the Araguaia, in Pará itself or in the neighboring states of Tocantins and Maranhão.
This is the contingency – unwanted but inevitable – of the superficial view that has defined the use of the Amazon’s mighty rivers for large-scale energy projects. The region’s rivers have two basic characteristics: a marked imbalance of flows between winter and summer, and a low gradient.
To compensate for the discreet natural gradient of the Tocantins, the dam builders had to raise an enormous 74-meter concrete wall in its bed to create an artificial drop with which to generate energy on a large scale. The new barrier caused the water to flow back over its course, full-bodied, for a length of almost 200 kilometers, spreading out to the sides, drowning land, trees and animals, as well as displacing people who lived on its banks.
It created an artificial lake with a perimeter of more than seven thousand kilometers, almost four times the length of the Belém-Brasília highway (or 17 times the Rio-São Paulo highway). But now other similar lakes have to be formed so that the energy paroxysm fits into economic feasibility calculations, which will certainly become even more rigorous if (and when) the privatization of the energy sector is completed.
The bitter conclusion of this reasoning is that Brazil, proud of its tradition as an expert builder of dams, particularly for the purpose of making hydroelectricity possible, is a country that is tremendously behind in its scientific approach to these works, in making these engineering achievements compatible with the conditions of nature.
This anachronism will take an even greater toll because, without correcting the design, Tucuruí will be surpassed in size by a new major energy project with the same characteristics: the Belo Monte plant, designed for 11 million kW on the Xingu, a river that is perhaps even more complicated than the Tocantins. The Xingu flows into what is perhaps the only inland delta on the planet, an intricate water system that will be below the future dam, suffering its effects.
What happened on the Araguaia-Tocantins with Tucuruí will be repeated on the Xingu with Belo Monte: the first hydroelectric dam will be started without a defined utilization plan for the entire basin. In the first case, the mistake was justified by its pioneering spirit: little was known about the Amazon, much less than was necessary to ensure the safety of a project the size of a large hydroelectric plant.
But the current situation is quite different. So much so that two of the projects initially planned by Eletronorte for the Araguaia-Tocantins, the Marabá and Santa Isabel dams, had been discarded due to their enormous ecological cost. The state-owned company itself accepted this condemnation. The problem is that at the time it was thought that Tucuruí had no dependence on the two new hydroelectric dams. Today, it is impossible to deny that increasing the capacity factor of the first plant will only be possible with upstream regularizations.
Can’t the same be said for Belo Monte? Eletronorte canceled the disastrous set of complementary dams, Babaquara and Juruá, which would have flooded more than 7,000 square kilometers. But when the big Xingu dam starts operating, having to be completely inactive for a quarter of the year due to lack of water, won’t the pressure game to build dams upstream begin?
Reflecting on the racial problem in his country in the 1960s, the American writer James Baldwin predicted that the next conflict would result in fire, referring to the racial issue in the United States. In the Amazon, in the face of the unbridled search for energy in the rivers, it will be a flood.
