Delivering consistent and reliable electricity in the Amazon rainforest—one of Earth’s most isolated regions—goes far beyond installing solar panels or erecting transmission towers. Since wind and solar energy are intermittent, grid managers must constantly balance supply and demand to maintain stability. The new Azulão I thermal power plant in Brazil is designed specifically to meet this challenge. Utilizing GE Vernova’s advanced 7HA.02 gas turbine technology and custom-designed blocking filter systems, the facility rapidly responds to fluctuations in renewable generation, enhancing grid resilience and enabling Brazil to expand its clean energy capacity.

Brazil’s Ten-Year Energy Expansion Plan forecasts that renewable sources will supply over 85% of the nation’s electricity by 2035, driven largely by growth in wind and solar installations. As weather-dependent energy sources become more prevalent, grid operators require flexible, dispatchable power to balance supply during periods of low renewable output and meet peak demand. Azulão I is engineered to deliver exactly that.

Developed by Eneva, Brazil’s leading thermoelectric power producer, the 295-megawatt Azulão I gas power plant ensures dependable electricity delivery to the National Interconnected System, operating whenever needed—regardless of sunlight or wind conditions.

The plant’s location, however, introduced a significant engineering hurdle. Power from Azulão I flows into the Tucuruí–Macapá–Manaus transmission corridor, a nearly 1,200-mile route through one of Brazil’s most complex electrical networks. To ensure seamless integration, teams from three GE Vernova divisions—Gas Power, Electrification, and Consulting Services—collaborated closely. Their combined expertise in turbine technology, grid integration, and system modeling enabled them to anticipate and resolve potential interface risks, ensuring the plant and transmission system function as a unified entity.

Engineering for a Thousand-Mile Grid

Transmitting electricity efficiently over such vast distances requires series capacitors, which boost the power-carrying capacity of transmission lines. However, these devices can introduce harmful sub-synchronous oscillations—known as sub-synchronous resonance (SSR)—that may lead to widespread blackouts, equipment damage, or even catastrophic generator failure, including fractured shafts.

Early in the project, GE Vernova flagged SSR as a potential threat during discussions with Eneva. Power systems engineers conducted detailed simulations of the transmission network, analyzing capacitor setups, maintenance scenarios, and the interaction frequencies between the grid and the turbine-generator set.

The analysis revealed that standard capacitor configurations could not prevent SSR under all operating conditions. Given that the problematic frequencies depend on both the turbine-generator design and local grid characteristics, the team developed a custom blocking filter tailored specifically for Azulão I. Positioned in the generator’s output path, this device blocks dangerous oscillations by filtering out the precise frequencies that could destabilize the system.

“A generic filter wouldn’t account for site-specific resonance patterns,” says José Geraldo Barreto Monteiro de Andrade, managing director for Latin America at GE Vernova’s Consulting Services. “We needed a solution precisely tuned to the turbine-generator’s risk profile.” Typically, blocking filters are added after SSR issues emerge post-operation. At Azulão I, protection was integrated during the design phase—before the equipment faced any risk.

Engineering the Plant and Grid as One System

With the SSR risk clearly understood, GE Vernova applied these insights to the plant’s grid interconnection design. The engineering team optimized the coordination between the turbine-generator, protective systems, and the broader transmission network to function as a single, integrated system.

“Azulão I shows what’s possible when generation technology, grid stability solutions, and system-wide engineering are aligned from day one,” says Ivette Castillo, general manager of Grid Systems Integration for GE Vernova in Latin America. “By viewing the power plant and transmission corridor as a unified system, we identified critical interactions early, engineered targeted safeguards, and ultimately protected the entire infrastructure.”

GE Vernova’s local engineering team brought deep regional expertise, partnering closely with Eneva from the project’s inception. “Rather than reacting to SSR after commissioning, we proactively addressed it during the engineering phase—thanks to Eneva’s confidence in our technical capabilities,” notes Castillo.

Comprehensive grid studies also led to customized operational protocols. Since SSR risk varies with transmission system configurations, the team established special procedures to safeguard the turbine-generator during outages or maintenance on adjacent infrastructure.

These protocols were successfully implemented during the commissioning and testing of the first turbine-generator units. The same rigorous evaluation is now being applied to two additional units, incorporating insights from the initial deployment. This knowledge will continue to inform operations over the next 15 years, as GE Vernova supports Azulão I under a long-term service agreement covering engineering, installation, and ongoing maintenance.

Supporting a More Flexible Power System

“Reliable power during renewable variability makes flexible gas generation essential to low-carbon energy systems,” says Marco Vera, general director and VP of new units for GE Vernova’s Gas Power business in Latin America and the Caribbean. “This project illustrates how integrating flexible generation with advanced grid technologies creates a more stable and balanced energy future.”

Azulão I is just the first stage of a larger initiative. Combined with the nearby Azulão II facility, the full complex is expected to deliver up to 950 MW of capacity—enough to power approximately four million Brazilian homes—with full commercial operations anticipated by Q1 2027.

For Andrade, the project underscores a crucial shift in how remote energy projects are conceived. Long-distance transmission lines are not just passive conduits—they actively interact with power generation equipment.

At Azulão I, identifying this interaction early allowed engineers to embed protective measures during design, adapt operations to dynamic grid conditions, and successfully connect a major new power source to one of Brazil’s longest high-voltage transmission corridors.

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