DR1 Daily News - Dominican Republic

A nationwide power outage that plunged the country into darkness for several hours on Tuesday, November 11, has been traced back to a critical operational error.

The root cause of the general blackout was the manual disconnection of an energized line at the 138 kV San Pedro de Macorís I substation, according to a technical report released Wednesday, 26 November 2025 by the Coordinating Body of the National Interconnected Electric System (OC-SENI).

The report details how this action triggered a catastrophic sequence of failures across the grid:

High-intensity short circuit: The manual disconnection immediately generated a high-intensity short circuit, which activated the system’s protection mechanisms.

The ‘cascade reaction’: As part of a protective cascade reaction, several nearby transmission lines automatically disconnected to isolate the fault.

Generation loss and imbalance: This isolation caused a massive 575 MW of Eastern generation capacity to separate from...