A massive failure in the National Electric System (SEN) caused a total blackout in Eastern Cuba this Sunday, leaving several provinces in the region without electricity and also affecting the western part of the country, particularly Unit 6 of the Mariel thermoelectric plant.
According to by the Electric Union (UNE), the outage occurred at 7:37 p.m. on September 7, when the 220 kV Nuevitas-Tunas line tripped, completely disconnecting the system from Las Tunas to Guantánamo.
The state entity indicated that the causes were under investigation; however, later the official journalist Lázaro Manuel Alonso reported on his that the disconnection was caused by “adverse weather conditions” and a very low generation in the eastern region at the time of the event.
Moreover, the blackout had repercussions in the western region: unit 6 of the Mariel thermoelectric plant went offline and its return to service is scheduled for this Monday, according to the same report.
After the collapse, recovery efforts began. In the evening hours, the UNE reported on that Las Tunas was the first province to be reconnected, and from there, a gradual re-energization process started.
Shortly thereafter, the current reached Camagüey, Holguín, and the main substations of those provinces.
The company also confirmed that energy had been reached in Santiago de Cuba, and that the goal was to continue advancing towards the easternmost part of the country.
In that regard, the strategy was proposed to reach the engines in Moa and then the Renté plant in Santiago, with the aim of starting up its unit 6 and strengthening local generation.
In the early hours of Monday, the Ministry of Energy and Mines officially announced that Guantánamo had been reconnected. “Power has been restored to Guantánamo. The restoration of the Electric System in eastern Cuba is ongoing,” the entity reported on .
Despite these announcements, the situation remains critical. The generation deficit in the country is very high, which keeps prolonged blackouts in effect, as acknowledged by UNE itself and official media such as Canal Caribe.
The frequent collapses of the SEN reflect the structural deterioration of the energy infrastructure in Cuba, as well as the inefficiency in the planning and maintenance of the system. Meanwhile, millions of Cubans continue to face daily power outages with no definitive solution in sight.
Cuba in Darkness: Timeline of an Endless Energy Crisis
The collapse of the National Electric System (SEN) that occurred on September 7th in the eastern part of the country is not an exception, but rather part of an ongoing chain of massive blackouts that reflect the deep and structural deterioration of the Cuban energy system.
Despite the repeated official announcements and contingency strategies, the situation is not only not improving but is actually worsening over time.
During the first days of September, the population was already living under constant alerts. The Electric Union warned that demand was greatly exceeding generation capacity, that key units were out of service, and that the system was operating under conditions of critical instability.
The national deficit was around 1,900 MW, practically half of the total demand, with several thermal power plants shut down, including Mariel 6, Felton 2, Diez de Octubre 5, and Guiteras.
This new blackout, which left the entire eastern part of the country without electricity and impacted the western region, adds to a series of similar events that have shaken the Island in recent years.
In August, Havana and other cities experienced prolonged power outages due to a deficit of nearly 1,800 MW, while another collapse of the national electrical system was reported in June, with higher figures of impact.
The Cuban electrical system has been operating under precarious conditions for years. Many of its thermal power plants have been in operation for over 40 years, there is a chronic shortage of fuel, a lack of spare parts, and a demotivated or emigrated technical staff.
The solutions proposed by the regime, such as the installation of mobile generators or the segmentation of the system by regions, have failed to provide lasting stability.
This is compounded by the public perception of a prioritization of tourism and economically significant areas, while households face daily blackouts ranging from 8 to 16 hours. During one of the most recent outages, hotels remained illuminated while entire cities were left in the dark.
The situation has caused social unrest, protests in several eastern provinces and a deep deterioration in the quality of life, impacting the water supply, food preservation, access to healthcare, education, and work life.
Chronology of Recent Massive Blackouts and SEN Collapses in Cuba
- 7th of September, 2025
- Total disconnection of the electrical system in the east following the triggering of the Nuevitas-Tunas line. Services are interrupted from Las Tunas to Guantánamo. Mariel 6 is also taken out of service.
- August 4, 2025
- Record deficit of 1,799 MW. Blackouts are reported in Havana, the west, and the center of the country.
- June 26, 2025
- The deficit exceeds 1,800 MW. Reports from all provinces confirm prolonged blackouts lasting more than 10 hours.
- 22 de mayo de 2025
- Massive blackouts spark protests in Santiago and Holguín. Se mantiene un déficit superior a los 1,700 MW. El viceministro de Energía y Minas, Argelio Jesús Abad Vigoa, aseguró que los apagones que afectan a millones de cubanos they were not the result of internal errors, but rather of the "criminal American blockade against Cuba".
- 15 de marzo de 2025
- Nationwide blackout. Las principales ciudades y zonas rurales quedan sin servicio. Se reporta que solo los hoteles mantienen la electricidad.
- 16th of March, 2025
- A survey reveals that 72% of Cubans were still without electricity following the blackout the previous day. In Santiago, only less than a third of customers were partially reconnected.
- 22 de octubre de 2024
- Apagón total en Santiago de Cuba. Residents report only 3 hours of electricity daily.
- 8 de noviembre de 2023
- Se registra un general blackout in several provinces of the east.
- 19th of October, 2024
- The Guiteras thermoelectric plant is offline. A nationwide blackout occurs. Airports operate in darkness.
This timeline clearly shows that the collapses of the National Electric System are not isolated incidents, but symptoms of a systemic energy crisis. While the government continues to blame external factors, the national infrastructure keeps failing, leaving millions of Cubans literally in the dark.
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