A fault at Felton, the eastern thermal power station, disconnected the provinces from Holguín through Guantánamo on 27 August, taking units at Nuevitas, Santa Cruz del Norte and Renté down with it 1. Unión Eléctrica (UNE), the state operator of Cuba's national grid, had forecast a 2,060 megawatt (MW) deficit against 3,200 MW of demand that day, better than the 2,240 MW it forecast in mid-July and still enough to darken most of the island at the evening peak.
Felton took the whole national system down on 14 July , and the grid collapsed completely between 1 and 3 August . UNE's thermal fleet keeps no spare capacity turning behind it, so a sudden loss drags the system frequency down until protection relays disconnect whatever is nearest, and the fault travels outward instead of staying where it started. That is why a single plant's problem in Holguín reaches Renté, and why the useful question about any Cuban outage is not what broke but what was already offline when it did.
No one has published a fuel-arrival count for this window. A House of Commons Library briefing of 17 August, citing the International Crisis Group, reports that Venezuelan shipments to Cuba ceased after January and that Mexican shipments paused 2, and both changes predate the period covered here. Searches found no dated cargo arrival at Matanzas, Santiago de Cuba or Havana between 4 August and 8 September. An absent record is not a record of absence, so the supply position is unquantified rather than proven empty.
