The difficult choice
Isaías Macedo lists alternative sources and hopes that the crisis will generate
permanent habits, common sense and awareness of waste

CARLOS TIDEI

There is no single and easy answer to the current Brazilian energy crisis. All studies must consider several alternative energy sources in the medium and long term. In the short term (until the end of 2001) the only solution is to reduce consumption, as has been occurring in recent weeks. It must generate more permanent habits, where common sense and awareness of waste will prevail. The causes of the current crisis are widely known: there was a reduction in the volume of rainfall, investment in the hydroelectric sector and a delay in the implementation of gas thermoelectric plants.

The opinion is that of Professor Isaías Macedo, advisor to the Rector of Unicamp, who has a solid academic base and experience from many years of services provided to Copersucar's technology development. It lists the possible alternatives in Brazil today: 1) actions to optimize, improve and expand the use of available hydraulic energy; 2) installation of gas thermoelectric plants, as a permanent complement to the Brazilian energy matrix; 3) investments in biomass energy generation with commercial technology; and 4) complementary actions in wind and solar energy.

According to Macedo, Brazil is currently experiencing a movement similar to that which occurred during the oil crisis in the 70s, in search of alternative energy sources. “In 74, Unicamp began a large energy program, initially set up with the Institute of Physics and the Faculty of Engineering, also covering Food Engineering and later other departments. The program had 70 people working in the area of ​​alternative energy and grew a lot due to the oil crisis. Today it is dispersed among some groups and we are trying to reunite these researchers. It would be very important to have activities involving specialists from various areas, maintaining the characteristics of existing groups. Problems of energy generation and use are multidisciplinary”, says Macedo. The costs of “new” hydroelectric energy, when considered broadly and without including some externalities, are still very attractive, but alternatives such as those mentioned are already viable.

Thermoelectric – What happened with the gas thermoelectric installation program, recalls Isaías Macedo, is similar to what happened with alcohol in the 80s. Pro-Álcool was established with quotas per producer and a guarantee of government purchase of these volumes, the price defined based on cost audit by an independent body (in this case, Fundação Getúlio Vargas). When this commitment was no longer fulfilled, producers chose not to produce quotas and export sugar, leading to a shortage of alcohol. In the case of gas, the problem occurred even before the installation of the plants: the purchase of gas and energy supply at prices defined before the devaluation of the real made investments unfeasible (and paralyzed).

The capital investment in a gas plant is relatively lower and the installation of thermoelectric plants is faster, compared to new hydroelectric plants. The problem currently (once the impasse between gas prices and electricity rates is resolved) would be the supply of equipment. We will compete with the American market, which should quickly move in the same direction. “But from the moment you start investing in the sector, suppliers appear. It is a tremendous market for energy companies around the world”, believes Macedo.

To be continued ...

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Solar energy has a guaranteed market
For Ivan Chambouleyron, technology will contribute
for the integration of the national territory

Photovoltaic energy (electricity generated with sunlight) is viable for supplying regions very far from conventional energy generating centers and transmission lines, and its future is guaranteed by some characteristics: it is clean energy, from an inexhaustible source, and the industrial growth can lower its cost. The equipment to generate photovoltaic energy is still expensive when compared to other production systems, such as hydroelectric and thermoelectric plants, but currently this industrial activity is among the fastest growing in the world, at around 30% per year, with the gain in scale should reduce its cost in the coming years.

“Today it is not a solution to the energy crisis. But for some applications, such as telecommunications, photovoltaic generation is widely used. This technology is important for Brazil, because by bringing energy to distant regions in the interior of the country, it will contribute to the integration of the national territory”, assesses professor Ivan Emílio Chambouleyron (photo on the right), pro-rector of Research at Unicamp and specialist in energy alternatives.

According to him, one of the best applications of photovoltaic energy is its use in water pumping systems for irrigation in regions where there is no electricity. “It would allow a huge leap in agricultural productivity”, he believes. “In the future, we could also use it in this way in 'dry river' hydroelectric systems, where during the day the sun's energy would be partially used to pump the water that has already passed through the turbines back to the dam, keeping it always full”, explains the teacher. This would be an alternative to the type of crisis currently experienced by Brazil.

Although apparently similar, the photovoltaic energy production system is not the same as that used in homes to heat water. The solar heater (which can also provide savings by deactivating the electric shower, responsible for around 6% of all electrical energy consumed in Brazil) simply uses the sun's heat to heat the water used in showers and taps.

Sophistication – The production of solar cells, basic elements of photovoltaic energy, requires relatively sophisticated technology. Currently, electricity from solar sources is used in the electrical distribution network in some developed countries, such as the United States, to complement conventional generation at peak times. In very distant places, such as the interior of the Amazon, on offshore platforms, sailboats and, above all, artificial satellites, it is an ideal source of energy.

Another example of the advancement of this technology is the vehicle race held periodically in the Australian desert, the “World Solar Challenge”, with cars powered exclusively with photovoltaic energy. “It is a technology that has been developed for many years. At first it was financed by government agencies, but currently it is a very profitable private industrial activity. Within twenty years, many countries, mainly in Europe, as well as the USA and Japan, will be using this source to complement the electrical distribution system”, predicts Chambouleyron. (CT)