22OCT

UNE blames line trip for Cuba blackout

3 min read

17:12UTC

Cuba's whole grid went down at 1:57pm on 18 September after, by the grid operator's account, a line out of Matanzas tripped and split the island.

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Key takeaway

Cuba's grid collapsed completely on 18 September, its first total failure since August.

Cuba's national grid disconnected completely on Friday 18 September; the US Embassy in Havana timed the failure at 1:57pm and reported mobile and internet outages⁠¹. UNE (Unión Eléctrica), the state grid operator, said the 220 kV line from Matanzas to Cienfuegos tripped first, then the line to Santa Clara, splitting the island before the whole system fell⁠². It cited unstable weather. That evening UNE gave no timeline for full restoration⁠³.

On Lowdown's count it was the seventh total collapse of 2026 and the first since 2 August; that count leaves out the failed reconnection attempt of 3 August. A 220 kV line failure had also brought the national grid down on 10 July, so twice in ten weeks a fault on one high-voltage line has started a national collapse.

Deep Analysis

In plain English

Cuba has one national power grid that links its power stations to homes and businesses across the island. On 18 September two big power lines in the middle of the island switched off one after the other. The grid split in two, and then the whole system shut down, leaving the island without electricity. Phones and the internet failed in many places too. The state power company blamed bad weather and gave no timeline for full repairs that evening. It was Cuba's seventh complete blackout this year by Lowdown's count.

Deep Analysis

Root Causes

Cuba's largest thermal plants sit in the west and centre, while demand spreads along the whole length of the island. Power travels long distances on a few 220 kV lines, so the loss of one corridor leaves whole regions without their main supply.

The Matanzas-Cienfuegos and Matanzas-Santa Clara lines failed in the same order in the 1-3 August collapse sequence, so the 18 September event repeats a known weak point rather than a new one.

Old thermal units take hours to restart after a blackout and often fail on the way back up, which is why restoration after each collapse runs into days.

Escalation

Persistent. Total collapses have recurred through 2026, and UNE reported 740 MW available on 16 October against 990 MW on 16 July.

What could happen next?

Risk
A further trip on the Matanzas corridor during the hurricane season could bring another total collapse.
Consequence
Each restart wears ageing thermal units further, feeding the breakdowns that deepen the deficit.

Source Landscape

This story draws on neutral-leaning sources

Primary parallel: On 21 September 2016 a fire at the Aguirre plant's switching yard in Puerto Rico took down the whole island grid, leaving about 1.5 million customers without power for up to three days. Like Cuba, Puerto Rico runs an island system with no interconnector, so a single fault on a main corridor can bring down everything.

Counter-parallel: Sri Lanka, short of fuel in 2022, imposed scheduled power cuts of up to 13 hours a day. It avoided repeated total collapses by cutting load on a timetable, showing that a deficit grid can stay up if the operator sheds load before frequency falls.

Each total collapse halts water pumping, refrigeration and mobile and internet service; the US Embassy reported phone and internet outages on 18 September. Food spoilage in homes and shops, and lost working hours in private firms, carry costs no official series measures.

The Empresa de Gas Manufacturado said gas volumes lacked the pressure to restore piped-gas service, so households lost cooking fuel as well as power. Repeated restarts also wear thermal units, raising the chance of the breakdowns that cause the next deficit.

Consensus view: Independent Cuban outlets 14ymedio and Diario de Cuba, which log every national blackout, describe a grid built as a long east-west chain with the Matanzas corridor at its waist. When the 220 kV line to Cienfuegos and then the line to Santa Clara tripped, the island split into halves whose generation no longer matched their load, and with almost no spinning reserve neither half could hold its frequency.

Counter-view: Unión Eléctrica (UNE), the state grid operator, attributed the trip to unstable weather, a transmission event rather than a generation failure. On that account the plants were not the trigger, and a stronger line or faster protection would have kept the halves apart without a total fall.

Key tension: Whether weather is the cause of these collapses or only the trigger on a system that has no reserve margin to absorb any single line loss.

Sources:US Embassy in Havana·14ymedio·CiberCuba

Mentions:UNE →Matanzas →Cuba →Puerto Rico →Havana →Sri Lanka →Santa Clara, Cuba →US Embassy in Havana →Empresa de Gas Manufacturado →

First Reported In

Update #15 · Cuba opens oilfields, US cuts dollar routes

US Embassy in Havana· 22 Oct 2026

Read original →

Causes and effects

Caused by

UNE blames a 110kV fault, not a storm

The 18 September collapse was the first total disconnection since the 2 August collapse.

Occurred 2 Aug 2026

Read story →

This Event

UNE blames line trip for Cuba blackout

A single trunk-line failure can still take down Cuba's entire grid; 18 September was the second such collapse in ten weeks.

Different Perspectives

UN General Assembly

The Assembly passed last year's resolution against the US embargo by 165 votes to 7, with 12 abstentions, and votes again on 28 October. That count is the baseline against which Havana's lobbying claims and Washington's pressure will be measured.

Mexican Navy (Secretaría de Marina)

A Mexican Navy team inspected Grace at Progreso and found fuel in its ballast tanks, according to the US Coast Guard. The account of Mexico's role comes from Washington; the Mexican government's own position on the stop is not on record in the sources reviewed.

Pedro Monreal, independent Cuban economist

Monreal says the gazette contains no rule for the exchange-house licence ADT 64 received, so nobody knows how a second firm could apply. He says a representative rate would need at least ten houses in five provinces, Havana included.

Prisoners Defenders and OCDH (Madrid-based exile monitors)

Prisoners Defenders counted a record 1,351 political prisoners at the end of September, and OCDH logged at least 344 repressive actions that month. OCDH asked the European Union on 11 September to investigate possible trafficking in Cuba's medical brigade in Italy.

Florida Attorney General James Uthmeier

Uthmeier announced a no-bond state warrant for Raúl Castro on 19 October over the 1996 Brothers to the Rescue shootdown, after reopening the state investigation last year. The four men killed flew for a Miami exile group, and the warrant restricts Castro's travel rather than reaching him in Cuba.

Cuban government (Foreign Minister Bruno Rodríguez Parrilla)

Rodríguez said on 21 October that Washington is pressing governments to abstain or leave the hall in the 28 October UN vote and called Florida's Raúl Castro warrant worthless. Havana is presenting its October oil and trade rules as openings and the US measures as an energy blockade.

Written with AI from Lowdown's published reporting. Not individually reviewed by an editor. Editorial standards.