SANTO DOMINGO. – The “manual disconnection” of a still-energized line at the 138 kV substation of San Pedro de Macorís I was the origin of the blackout generated in the country on November 11, which disrupted the national economy for several hours.
This is according to the technical report published by the Coordinating Body of the National Interconnected Electric System (OC-SENI), available for public consultation on the institutional website, which details that the incident generated a high-intensity short circuit that immediately activated the SENI protection systems.
report highlights that, as a cascading reaction, several nearby lines were disconnected to isolate the fault, cutting off the eastern generation capacity—equivalent to 575 MW—from the rest of the system, causing an imbalance between supply and demand.
The report indicates that although the frequency stabilized within the first 89 seconds, the system remained weak due to the lack of synchronized cold reserve and the incomplete restoration of the EDAC circuits, resulting in a sharp drop in frequency and a total loss of power.
The report, prepared by a multi-sector team of specialists, emphasizes the speed with which it was completed—within the same month as the incident—in contrast to international experiences where similar processes have taken up to five months.
Actions:
The OC-SENI announced several corrective measures to improve the safety and efficiency of the electrical system, including the installation of protective devices at substations, operational adjustments for new generation technologies (thermal and renewable), integration of battery storage, review of protection and automatic switching operation times, and verification of high-frequency criteria at power plants.
The OC-SENI remains in permanent session to monitor compliance with these recommendations and ensure the system's improvement.
As a direct and immediate consequence of the blackout that occurred on the 11th, service on lines 1 and 2 of the Santo Domingo Metro and the Cable Car was paralyzed, forcing the evacuation of passengers who were stranded in the cars and cabins, in addition to generating vehicular chaos in Greater Santo Domingo due to the inoperability of the traffic lights.
The Coordinating Body of the National Interconnected Electric System is the entity in charge of supervising the operation of the Dominican electric system in real time, according to article 216 of the Regulations of Law 125-01.
It has the power to convene market agents in the event of failures or incidents, issue conclusions, recommend actions and ensure the correct operation of the SENI under criteria of safety, quality and economy.
