at about 9: 30 p. m. on Sunday, the state power department announced that the state power system (SEN) had been interconnected from pinar del rio province to guantanamo province, marking the completion of uninterrupted repair work lasting more than 30 hours. A day earlier, a new round of blackouts plunged Cuba into darkness again, the second such accident this week. The announcement marked the end of a day that started with an uncertain outlook but added the necessary pieces to the nation's energy puzzle step by step.
"Microgrid" Maintains Basic Operation Since noon, official reports paint a picture of steady but sustained progress. The Ministry of Energy and Mines (MINEM) reported at 6 p.m. that unit 1 of the Santa Cruz thermal power plant, units 3 and 4 of the Carlos Manuel de Cespedes plant, the Engas Bokard de Haruko and Varadero plants, and the Antonio Gillera thermal power plant in Matanzas province were connected to the grid. These complement the microgrids that maintain critical services in western and central Cuba during the day, creating the necessary conditions for expanding connectivity to the eastern region, which is most affected by prolonged power outages.
At 7: 42 p. m., the national power department announced that the system had been interconnected from pinar del rio to Santiago de Cuba and that it was working on connecting Granma and Guantanamo provinces. Less than 20 minutes later, at 7.59 p. m., confirmation came that the province of Granma had been integrated into the national electricity system. The complete interconnection, including Guantanamo Province, was finalized shortly before 9: 30 p. m.
As the country moves towards interconnection, the province of Las Thunas is undergoing its own recovery within the confines of the eastern region. As of Sunday morning, the province maintained an energy microgrid with a steady generating capacity of 15 megawatts (MW). Among them, 10 MW came from the distributed generation points in the provincial capital cities-that is, the same batch of stations that started power generation in the early morning, and the remaining 5 MW were provided by photovoltaic power generation parks. Experts explained that the limited use of solar energy is due to safety concerns: these parks still have no storage systems to stabilize frequency and power. As a result, only a portion of the capacity is used to support microsystem stability without compromising operation. With this capacity, medical services in the cities of Las Tunas and Puertopadre, as well as the water supply from the capital, were maintained as the agreement established by the State Electricity Department continued to be implemented.
In the evening, the existing distributed generation points in Pueto Padre are connected to the grid to replace the power supply of the solar park and maintain the stability of the system. One piece of good news today comes from the Lidio Ramon Perez power plant in Mayari, Olguin, Orente. Unit 1 of the Felton power plant was not damaged during the shutdown of the national power system. Its technicians have conducted a comprehensive evaluation of all systems. Once the external power of 110 kilovolts (kV) and 22 kV is received, the technical conditions for start-up can be met, which is a key step before synchronization. By contrast, the timetable for the 10 October reentry of the power plant in Nova Villiers, Camaguey province, is not yet clear. The output of the plant, together with the Felton plant and the Lent plant in Santiago de Cuba, is essential for the establishment of an independent microgrid in eastern Cuba and eventual access to the national grid.
Recovery is not easy The recovery process is not without obstacles. In the central region, a failure of the 110 kV line in La Lima, Manikar Agua, caused the Hanabanira hydropower station to go offline and weakened the microgrid in Biaclala province that was started the day before. The facility is crucial for frequency regulation, as thermal power plants in the western and central regions are being connected to the grid, a reminder that infrastructure remains fragile even as we move towards normalisation.
In Matanzas province, the Antonio Gillera power plant continued its start-up process on Sunday. After the boiler was filled with water, the process took six to eight hours and no major damage was reported, although the final result was, as usual, known only after ignition. The addition of the Gillera power plant is essential to reach the critical scale of power generation capacity, which makes interconnection with the eastern region possible.
As part of the recovery process, the Department of Education announced that schools would resume classes on Monday, adopting flexible measures applicable to general power outages. Students are allowed to wear casual clothes to school and the double shift schedule will be adjusted according to the capacity of each school. This measure, aimed at minimizing the disruption of the school calendar, reflects the desire to return to normal daily life at a time when the power system is still struggling to restore full stability.
Three power outages in less than a month To understand the scale of what happened, it's important to remember that Saturday's outage was the third this month. The first occurred on Wednesday, March 4; the second on Monday, March 16; and the third on Saturday, March 21. Each time, the emergency plan was triggered, the response ability of the power team was tested, and the people experienced several days of uncertainty and hardship.
The authorities have consistently stated that these power outages due to system vulnerability are caused by a combination of structural and external factors. The former includes ageing infrastructure and lack of sustained investment; in the latter, the decisive factor is the increasing economic, commercial and financial embargo imposed by the United States Government. The shortage of diesel and heavy oil is a direct consequence of regulations restricting Cuba's access to fuel on the international market, which limits access to distributed power generation technology and is a major obstacle to accelerating recovery from emergencies.
Under normal circumstances, the spread of the ancient generator group could have supplied part of the gap, thereby shortening the recovery time. However, the lack of oil has forced the country to rely almost entirely on thermal power plants, whose start-up process is inherently slow and requires stable conditions, while the status quo remains fragile. This is no small matter. This explains why in the case of an undamaged outage, recovery takes days. This also explains why PV solar parks, despite the huge potential of the Caribbean midday sun, can only contribute part of the capacity due to the lack of energy storage systems, and the blockade also makes it difficult to obtain the system.
The system is in a state of extreme vulnerability. The state's power sector warned when announcing full interconnection that the national power system (SEN) is still in a state of extreme vulnerability. This is not rhetoric; it reflects the reality of a system that, although rebuilt, is operating at the limit of its capacity, has minimal reserves, and relies on each operating unit to remain stable.
Power authorities continued to work throughout Monday morning to consolidate interconnections, consolidate remaining units, and strengthen system reserves. At the same time, the public is called on to maintain the greatest degree of rationality in consumption, realizing that every saving of electricity contributes to the stability of a system that is still walking a tightrope.