LUMA to Install Largest Transformer in Puerto Rico's History

LUMA, the company responsible for operating Puerto Rico’s electric transmission and distribution system, announced on Nov. 6 the arrival of the largest and highest-capacity transformer in the island’s history. The transformer, to be installed at the Sabana Llana Transmission Center in Carolina, will directly impact more than 200,000 customers and indirectly benefit more than 700,000 by reinforcing the grid and providing greater stability to prevent large-scale outages. 

 

This project, fully funded by federal resources, marks a milestone in the modernization of Puerto Rico’s energy infrastructure. It enhances the electric system’s resilience against large-scale cascading events, offering peace of mind to hundreds of thousands of families. The investment of about $21 million covers the purchase, design, construction and transportation of the transformer. It is part of the broader reconstruction of the electric system in collaboration with the Federal Emergency Management Agency (FEMA), aimed at improving grid stability for customers from Manatí to the island municipalities of Vieques and Culebra. 

 

“This is one of the most important steps in LUMA’s ongoing efforts to stabilize Puerto Rico’s electric grid,” said Pedro Meléndez, chief officer of capital programs and grid transformation. He noted that since 2021, the company has launched more than 500 projects to enhance grid resilience, with nearly 200 projects completed or nearing completion.

 

Sabana Llana, one of Puerto Rico’s most critical substations, will receive the transformer following a complex logistical transport operation from the San Juan port to the substation in Carolina. 

 

“After months of coordination and close collaboration with the Department of Transportation and Public Works (DTOP), as well as the municipalities of San Juan and Carolina, this effort is becoming a reality. The Sabana Llana transformer is one of many that will continue arriving in the coming months. Nearly 50 modern units have begun arriving and will continue to arrive throughout 2026, nearly three years after the order was placed. This marks another key step in LUMA’s mission to improve the stability of the island’s transmission and distribution system.” 

 

Over the past four years, LUMA has ordered more than 80 transformers, with six already installed in 2025 as part of its grid modernization plan. Manufacturing and delivering these units is a complex process that can take between two and four years, depending on the country of origin, design specifications, required components and technical details. This specialized logistics effort reflects the scale of commitment to Puerto Rico’s energy transformation and the need for long-term planning to ensure a more robust and reliable system. 

 

Meléndez acknowledged the challenges involved in preparing for the transformer’s transport and emphasized the significant benefits it will bring once fully installed and operational at Sabana Llana in the first quarter of 2026. 

 

“This transformer stands approximately 14 ft tall, comparable in size to a two-story house, and weighs around 250 tons, similar to the weight of a passenger airplane. It represents a significant logistical challenge. Its transport from the San Juan Port to the Sabana Llana Transmission Center will require a carefully coordinated operation led by the Department of Transportation and Public Works (DTOP),” stated Meléndez. 

 

The transformer’s relocation was expected to take several days and involve temporary closures of frequently traveled routes in the metropolitan area. DTOP reviewed and approved the transport plan and route to minimize traffic impact and ensure compliance with all necessary safety measures. 

 

“At DTOP, we have worked closely with LUMA to ensure that this transport is carried out safely and with minimal disruption to traffic. These improvements to the electrical infrastructure also require road coordination, and our priority is to help drivers plan ahead and move efficiently during this operation. We appreciate everyone’s understanding and reaffirm our commitment to maintaining road safety and supporting projects that contribute to a more reliable electric system for Puerto Rico,” said Eng. Edwin González Montalvo, Secretary of the Department of Transportation and Public Works. 

 

“Our commitment to Puerto Rico is firm and unwavering," LUMA stated in its announcement. "In the face of bureaucratic challenges and funding limitations, we have worked tirelessly to advance critical projects that strengthen the electric system. We have spared no effort because we know our people deserve a stable, reliable, and resilient service."