New failure on a transmission line leaves eastern Cuba without power

File photo. The outage of the Nuevitas-Las Tunas transmission line caused a partial disconnection of the National Electric System in eastern Cuba. /(Norlys Pérez)The outage of the Nuevitas-Las Tunas transmission line caused a partial disconnection of the National Electric System (SEN) in eastern Cuba this Saturday, at a time when the grid was already facing a projected deficit of 1,680 megawatts (MW) for peak demand hours. The Electric Union (UNE) reported at 12:46 that the 220 kV line, an infrastructure linking Nuevitas with Las Tunas, had tripped. The incident affected the interconnection of a region encompassing the provinces of Las Tunas, Holguín, Granma, Santiago de Cuba, and Guantánamo. As reported by CiberCuba, the system was already going through a day of restrictions before the failure. At 06:00, availability stood at 1,250 MW against an estimated demand of 2,900 MW, while the impact on service reached 1,222 MW. The UNE had anticipated a maximum of 1,680 MW without coverage during the evening peak. The outage occurred two days after another interruption in the same area of the country. An oscillation in the transmission grid took Unit 1 of the Lidio Ramón Pérez thermoelectric plant, in Felton, out of service and caused blackouts from Holguín to Guantánamo. The fragility of the transmission corridors causes the fragmentation of the system and the isolation of entire regions when a line fails. /(Illustrative image Infobae)This week's official reports listed units from the Renté, Felton, Santa Cruz, Nuevitas, and Antonio Guiteras thermoelectric plants, located in Matanzas, as broken down or under maintenance. That combination reduced the grid's capacity to respond to problems in the high-voltage lines. The situation also highlights the dependence on transmission corridors that connect the different regions of the island. When one of those lines goes out of service, the system can fragment and leave entire areas separated from the rest of the national grid. On August 27, another oscillation isolated the provinces from Las Tunas to Guantánamo, following the outage of units at Felton, Diez de Octubre, and Antonio Maceo. Reconnection was completed the following day, according to data compiled by CiberCuba. The country has recorded at least eight total disconnections of the SEN since January, according to the count published by the Cuban outlet. Two occurred in March, three in July, two in August, and one on September 18. The process to restore the power grid after the September 18 collapse took nearly 15 hours of work. /(AP Photo/Ramón Espinosa)The March 16 blackout lasted 29 hours and 29 minutes. The September 18 one originated after the tripping of two high-voltage lines in Matanzas, and the restoration process took 14 hours and 45 minutes, according to information released by CiberCuba. Reuters reported at the time that the September collapse was caused by a failure in high-voltage lines in the center of the island. The agency noted that Cuban generation has long suffered from infrastructure problems and fuel shortages. The blackouts are not limited to general disconnections. Between September 3 and October 2, 23 of the 28 days with comparable records exceeded 2,000 MW of maximum impact, according to an analysis of UNE reports published by CiberCuba. On October 1 and 2, the maximum impacts reached 2,059 MW and 2,130 MW, respectively. In several eastern localities, residents faced outages exceeding 20 hours a day, amid generation failures, plant maintenance, and a lack of fuel for distributed generation units.