A preliminary inspection conducted this Saturday confirmed that the latest breakdown at the Termoeléctrica Antonio Guiteras, the largest power plant in Cuba, is located in the economizer of its boiler, according to the plant's own Facebook page.
The failure occurred during the eighth total blackout of the National Electroenergy System (SEN) so far in 2026, which took place on Friday at 1:57 PM following the successive tripping of two transmission lines of 220 kV originating from Matanzas— the Matanzas-Cienfuegos and Matanzas-Santa Clara lines. The mechanical stresses generated by that total disconnection may have exacerbated or triggered the malfunction at the Matanzas power plant.
The SEN was restored across the country at 04:42 hours this Saturday, but the Guiteras remained out of service due to a fault confirmed in that component.
The official report from the central indicated that, taking advantage of the mandatory downtime, the maintenance crews are also carrying out other tasks: "cleaning and adjustments of all the components of the burner nozzles and washing of the CAR (Regenerative Air Heaters)."
The economizer is a heat exchanger that preheats the feed water for the boiler using the waste heat from the flue gases, thereby improving the thermal efficiency of the plant. When it fails, it leads to steam losses that necessitate a complete shutdown of the unit.
This component has been the Achilles' heel of Guiteras throughout 2026. The plant recorded at least 17 unplanned outages from the SEN this year, with the economizer accounting for about half of them, according to reports on the state of Cuba's largest thermoelectric plant.
The component consists of 136 elements, each with three tubes, and failures have appeared in various locations, indicating widespread deterioration. In June, the plant director, Román Pérez Castañeda, explained that more than 100 defective weld seams would be replaced and that a failed seam had damaged three additional tubes.
The definitive solution would require replacing about 500 tubes and between 1,000 and 1,200 weld cords during a downtime of approximately 180 days, a capital maintenance task that the authorities have acknowledged they cannot execute at this time. Partial repairs —spot tube replacements and reworking of welds— create a repetitive cycle of shutdowns, brief reconnections, and new breakdowns within a few days.
La Guiteras, located in Matanzas, has an installed capacity of 320 MW, has been in continuous operation for approximately 38 years, and has accumulated 16 years without receiving a complete capital maintenance, a situation that the Cuban regime has acknowledged but has been unable to reverse due to a lack of resources.
The cooling of the boiler following a disconnection takes nearly 72 hours before the teams can inspect and make safe repairs, which means that the plant could not return to the SEN for several days, extending the impact on an electrical system that on Friday recorded an estimated disruption of 1,400 MW during peak hours.
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