Puerto Rico’s Solar Microgrids Beat Blackout

When power went out across all of Puerto Rico on 16 April, a lot of the lights in the town of Adjuntas stayed on. There, nestled in the mountains on the midwestern side of the island, a combination of experimental microgrids, solar panels, and storage kept power on for many businesses and residents. The rest of the island waited over 24 hours, and in some cases longer, for electricity to be restored.

The blackout was the latest in a series of power interruptions that have come to define Puerto Rico’s aging electrical grid. Vegetation was to blame for April’s blackout, according to LUMA Energy, the private company that manages the island’s grid. A faulty old cable triggered the near total blackout on New Year’s Eve 2024, the company said. Tropical storm Ernesto’s strong winds knocked out half of the island’s power in August 2024.

The problems are the result of decades of mismanagement and disinvestment in the island’s grid infrastructure. Neglecting to keep up with regular maintenance and failing to meet increasing demand for power generation have contributed to the disarray. The long-standing issues set the stage for the grid to be crushed in 2017 by Hurricane Maria, the United States’ second deadliest, which plunged Puerto Rico into months-long darkness and claimed nearly 3,000 lives.

After that hurricane, the island’s state-run utility Puerto Rico Electric Power Authority (PREPA) contracted with private entities for power generation, transmission and distribution in the hopes of fixing the grid. Over $20 billion in U.S. federal disaster relief was awarded by the Federal Emergency Management Agency (FEMA) to improve the grid and boost its resilience. Yet bureaucratic red tape and politics in Puerto Rico and on the U.S. mainland have hindered much of that money from being spent.

“It’s a blame game, and there’s too many cooks in the kitchen,” says Javier Rúa-Jovet, a former Puerto Rican regulator who is now Chief Policy Officer at the Solar and Energy Storage Association of Puerto Rico.

Now, the U.S. Department of Energy plans to redirect$365 million previously earmarked for rooftop solar toward infrastructure on Puerto Rico’s majority fossil-fuel powered grid, according to an announcement from the agency on May 21. The money will support “practical fixes and emergency activities that offer a faster, more impactful solution to the current crisis,” the agency said. This will include “system flexibility and response, power flow and control, component strength, supply security, and safety,” according to the announcement.