World's largest dam helps Brazil cut oil bill

Question: Where is the world's largest hydroelectric facility?

Answer: In Brazil, of course.

In Brazil, of course?

Yes. For this is a nation that deals in superlatives.

But even for Brazil, the Itaipu Dam on the Parana River bordering Paraguay was a huge undertaking. The biggest construction project in Brazil's history, it eventually will produce 12.6 million kilowatts, or the equivalent of about a dozen nuclear reactors.

Some Brazilians worried that the $12 billion project, which officially opened this month, might flounder. Yet most agreed it was necessary. Brazil's petroleum imports alone gobble up $10 billion a year worth of export earnings.

Itaipu's 18 massive turbines eventually will take care of the electrical energy needs of Brazil's industrial southland - the states of Sao Paulo, Parana, Santa Catarina, and Rio Grande do Sul - at least until the end of the century. Energy for the southland is critical because two-thirds of Brazil's gross domestic product comes from these states. Neighboring Paraguay is an equal partner with Brazil in building the dam.

When Itaipu is fully operational in 1988, those 12.6 million kilowatts of energy (also equal to 600,000 barrels of oil daily) will be more than enough for Brazil's southland and for Paraguay.

Some of the power conceivably could be exported, perhaps to Uruguay or Bolivia. But other Latin American countries are in their own races to overcome an energy shortage - except, of course, for oil-rich Mexico. Hydroelectric facilities now in operation, under construction, and on the drawing boards of half a dozen Latin American countries aim to double or triple energy generation during the next decade to provide for the region's exploding population, urbanization, and industrial expansion.

Although there is a world oil glut, most Latin American governments do not feel assured that petroleum will remain abundant and that the price will remain even.

Itaipu will cost upward of $20 billion when transmission wires, transformer stations, and other facilities are included, but Jose Cavalcanti Costa, head of the Itaipu construction consortium, says, ''This is cheap when you look at the $ 10 billion it is costing Brazil a year to import petroleum.''

Other Latin American nations reason the same way.

There are a number of strong rivers in Latin America - and therefore large hydroelectric potential. Estimates made available by international agencies suggest that less than 10 percent of the region's hydroelectric capacity is being tapped.

Even here in Brazil - where four projects on the Parana and half a dozen on the Sao Francisco are either in operation or about to be - only about 11 percent of the potential has been harnessed. The following is a rundown on other countries.

Venezuela: This nation is oil rich but is tapping hydro power, too. The huge Guri project in the eastern Guayana region drums out 9 million kilowatts of power. The Guri Dam and several smaller ones in the western mountains are seen as a safeguard against any diminution in Venezuela's oil potential.

Colombia: Hydroelectricity provides 27 percent of this country's energy and may provide close to 40 percent by the end of the decade. Domestic petroleum fields also provide some fuel.

Peru: The country has some 70 small hydroelectric facilities that supply regional needs but is far behind in big dam projects. The small projects provide an estimated 12 percent of energy needs and are expected to supply 22 percent by 1990.

Chile: A series of big hydroelectric facilities are under construction. These dams are expected to take care of 25 percent of national energy needs by 1990. At the moment, a number of smaller dams provide about 6 percent of the national need.

Argentina: Like Venezuela, this country has sufficient petroleum for its own needs. But Argentina has joined Paraguay to build hydroelectric projects at Corpus and Yacireta on the Parana River. Domestic economic problems have forced slowdowns on both facilities, and it is not clear when the Argentines plan to complete construction.

Uruguay: With facilities at Salto Grande and Palmar, which are shared with Argentina, Uruguay is more 50 percent covered with hydroelectric power.

Central American nations have limited hydroelectric potential, but they are planning to build 22 small dams and hydroelectric facilities.

Mexico: This is the only nation that is confident its vast petroleum resources will be sufficient to meet needs for decades to come. But heavy dependence on oil is also partially responsible for the nation's economic crisis. Mexico has vast potential in its rivers, too.

Brazil was looking for more water even as it opened the gates on the Itaipu project. Surplus energy from Itaipu will soften the need for new construction in the immediate future, but more will be needed for in long run. Brazil may not be able to afford huge new dams for a while, though. The foreign debt chalks up to about $80 billion.