Itaipú Simulates Up to 1,000 MW of Solar to Damp Oscillations in Paraguay

The binational entity Itaipú is studying the addition of photovoltaic plants of between 100 MW and 1,000 MW to Paraguay's electricity system, according to research presented on October 27, 2026 by pv magazine Latam. The work, presented by engineer Manuel Sosa Ríos of Itaipú's Technical Directorate at the Cigre Energy Forum 2026 held in Calgary, Canada, pursues a dual objective: meeting growing demand and improving grid stability.

The starting point is the arithmetic of supply. Paraguay has 8,800 MW of hydropower, distributed among Itaipú (7,000 MW in its 50 Hz system), Yacyretá (1,600 MW) and Acaray (200 MW). The planning studies cited by the researcher indicate that this capacity would fall short around 2029. The country records an average annual global horizontal irradiation of 5.08 kWh/m² per day, a figure that supports the evaluation of photovoltaics among the alternatives.

The work also addresses the interconnection with Argentina, which has operated in its current configuration since December 2022 and exhibits inter-area electromechanical oscillations of between 0.33 and 0.41 Hz. Today Itaipú's power system stabilizer (PSS) is the main damping mechanism, with limited response under certain underfrequency conditions. The researchers added a power oscillation damping (POD) controller to the solar plant models, tuned with the damped Nyquist method, and simulated three connection points: the Villa Hayes 500 kV, Villa Hayes 220 kV and Acaray 220 kV substations. Without Itaipú's PSS, the model showed an unstable 0.4 Hz inter-area mode with negative damping of 4.96%; with photovoltaic generation and the POD controller, the system was stabilized at all three points. The study also recommends battery energy storage systems (BESS) alongside the solar plants and proposes evaluating other locations and control signals.

The results come from simulations with generic models in the Anatem program, not from an approved project. For systems with high renewable penetration such as Mexico's, the case offers a reference on how the control of a solar plant can support grid stability. The next technical step is extending the study to more nodes.

This article was drafted with the assistance of artificial intelligence from verified sources and reviewed by a human editor before publication.