Paraguay supplies 99% of Brazil's imported electricity in 2025

Brazil's reliance on a single partner for its imported electrical energy reached an extreme in 2025, with Paraguay supplying 98.9% of the total US$910.7 million flow. This level of concentration, reflected in a Herfindahl-Hirschman Index (HHI) of 0.978 out of a possible 1.0, transforms the trade relationship into a structural dependency. It’s a corridor defined not by market competition but by shared infrastructure and a foundational binational treaty.

Where the risk sits

The overwhelming dominance of Paraguay is the direct result of the Itaipu Dam, the world's #2 largest hydroelectric plant by installed capacity. The 1973 Itaipu Treaty is the bedrock of this relationship. It stipulates that the 14 GW of energy produced is split evenly between the two nations. Crucially, it also obligates Paraguay to sell any unused surplus exclusively to Brazil. Historically, Paraguay has consumed only a small fraction of its share, making Brazil the default and sole buyer of a massive volume of power. This arrangement has long been a pillar of Brazil's energy security, providing a stable and, for many years, cost-effective power source that fueled industrial expansion in the country's south and southeast.

However, this deep integration creates a pronounced single point of failure. The vulnerability is not just commercial but physical. The entire trade flows through a handful of high-voltage transmission lines originating from a single geographic point. Any disruption—whether a major technical failure at the plant, a coordinated cyberattack on the grid, or a political disagreement over treaty terms—has immediate and direct consequences for Brazil's National Interconnected System (SIN). Furthermore, climate change introduces another layer of risk. Severe droughts in the Paraná River basin, like those seen in recent years, can drastically reduce the dam's output, forcing Brazil to compensate with more expensive energy sources. With only two other partners appearing in the 2025 data, their combined volume is functionally zero and offers no meaningful buffer.

Alternative routes

If the flow from Paraguay were to be disrupted, Brazil's options for substitution are limited, slow, and expensive. The country maintains energy interconnections with Argentina and Uruguay, but the scale is mismatched. These connections are designed for managing peak demand and seasonal balancing, not for replacing the gigawatt-scale baseload power that Itaipu provides. Ramping up imports from these neighbors would require material infrastructure upgrades and would almost certainly come at a higher market price, as their energy matrices are not structured to produce a massive surplus for Brazil on short notice.

The most plausible immediate alternative would be to ramp up domestic generation. Brazil's primary tool for this is activating its fleet of thermoelectric plants. These facilities, which run on natural gas, coal, or diesel, are typically kept on standby precisely for such contingencies. However, their operating costs are far higher than Itaipu's hydropower, which would translate directly to increased electricity tariffs for industrial and residential consumers. A prolonged reliance on thermal plants would also jeopardize Brazil's climate commitments, given their carbon emissions. While Brazil is a global leader in renewables, the lead time for building new large-scale wind, solar, or hydroelectric capacity is measured in years, not months, making them solutions for long-term diversification, not for an acute crisis.

A trade relationship this concentrated is less a market and more a utility.

Source: MDIC ComexStat

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