
Sistema Eléctrico Nacional
Cuba's National Electric System; collapsed entirely five times in 2026, including three times within eight days in July.
Cuba's national grid collapsed entirely for the sixth time in 2026, disconnecting completely on 2 August after a Havana substation fault; UNE blamed a 110kV fault while CNN and AP pointed to storm damage on a separate 220kV line.
Last refreshed: 4 August 2026 · Appears in 1 active topic
Cuba's grid has collapsed entirely five times in 2026; is the system now failing faster than it can recover?
Timeline for Sistema Eléctrico Nacional
Mentioned in: UNE blames a 110kV fault, not a storm
Cuba DispatchCollapsed a second time within the window after the Felton trip
Cuba Dispatch: Felton trips, and the grid falls againDisconnected entirely after the 220kV line failure
Cuba Dispatch: One 220kV line took the island darkSuffered its fourth total collapse of 2026
Cuba Dispatch: Nuevitas failure blacks out all CubaSEN splits east from centre at 06:09
Cuba DispatchBackground
The Sistema Eléctrico Nacional (SEN) is Cuba's national electric grid, operated by the state utility Unión Eléctrica (UNE). Its ageing thermal fleet, starved of fuel by the loss of Venezuelan and Russian crude imports and by US sanctions on Cuba's oil sector, runs with no reserve margin: when any single unit or transmission line fails, the whole grid can collapse rather than just the affected region.
That fragility has produced a recurring pattern since 2024: partial regional disconnections under UNE's load-shedding hierarchy, which prioritises Havana, punctuated by total national collapses that have now reached eleven since late 2024, six of them in 2026 alone. Restoration typically proceeds plant by plant, often through smaller microsystems first, and buys only weeks or months before the next failure because the fleet and fuel supply chain behind it remain structurally broken.
The grid failed a sixth time
The Sistema Eléctrico Nacional disconnected completely on 2 August, its sixth total collapse of the year and eleventh since late 2024, after a partial outage had already hit five provinces the day before. A reconnection attempt failed on 3 August.
UNE's load-dispatch director pointed to a 110kV Havana substation fault that set off a network oscillation and tripped the Felton plant in Holguín; CNN and AP instead attributed the collapse to storm damage on a 220kV line, and the two accounts have not been reconciled. Seven thermal units were already offline beforehand, leaving almost no spare capacity to absorb a single fault.
Three collapses struck within eight days
Before August's failure, the SEN had already suffered three total collapses in eight days: Unit 6 failed at Nuevitas on 6 July, leaving Matanzas dark for up to 87 hours, then a Santa Clara-Sancti Spíritus transmission line failed on 10 July, and the Felton plant tripped on 14 July, widening the deficit to 2,020 MW.
That cadence, roughly one collapse every few weeks through most of the year compressing to three within eight days, showed the grid running with no reserve margin: any single unit or line failure could take the whole system down rather than just the affected region.