Installation and Energization of Two New Transformers Will Reduce Outages for Hundreds of Thousands of Customers in San Juan, Caguas, and Carolina
San Juan, PR – December 29, 2025 – LUMA has brought the Monacillo Substation in San Juan to full operational capacity following the installation and energization of two large-scale transformers that strengthen the electric grid.
“This is a major achievement for the Island’s electric grid. With the energization of these two additional transformers, there are now four transformers operating at full capacity at the Monacillo substation. Now that Monacillo is functioning as originally designed, customers can expect a significant reduction in large-scale outages and improved service stability,” said Pedro Meléndez, Chief Capital Programs and Grid Transformation Officer. “This follows the installation and energization of another new transformer at Monacillo in October and a similar transformer at the Caguas substation in November,” he added.
Meléndez explained that the installation of these transformers demonstrates how LUMA is stabilizing the system by modernizing substations across the island. “Our priority is to improve system resilience and strengthen the grid’s defenses to prevent major events. These units require an extensive planning process that includes design, manufacturing, and international transport. Their energization marks the culmination of three years of planning and coordination.”
Prior to the upgrades at the Monacillo substation, electricity for tens of thousands of customers in high-demand areas had to be rerouted through more distant substations, often resulting in less reliable connections. He noted that more than half of the transformers currently in service at Puerto Rico’s substations have exceeded their useful life and maintenance cycles.
He also emphasized that the system continues to degrade at an estimated rate of 4% to 5% per year due to the critical condition of certain transmission and distribution components, according to industry data. For this reason, this project represents a significant step forward in stabilizing the system, Meléndez said.
About LUMA
LUMA is a Puerto Rican company that has operated and managed Puerto Rico’s electric transmission and distribution system since June 1, 2021. LUMA is driven by the mission to transform the transmission and distribution system to deliver a reliable, resilient, clean, and affordable electric grid for all Puerto Ricans. As a customer-focused company, LUMA’s workforce of over 4,300 employees is committed to providing an exceptional customer service experience to its 1.5 million customers.
