BAYAMÓN, Puerto Rico — Power was restored to nearly all residents in Puerto Rico on Wednesday following a significant blackout that left the territory in darkness on New Year’s Eve.

By the afternoon, Luma Energy, the private entity responsible for the island’s power transmission and distribution, reported that 98% of its 1.47 million utility customers had their electricity restored. This included vital facilities such as hospitals, water treatment plants, and sewage systems that had been affected by the widespread outage that highlighted ongoing electricity challenges on the island.

However, the company cautioned that residents might still experience brief outages in the upcoming days, with full recovery potentially taking another two days. “Given the delicate condition of the grid, we will need to manage the available generation to meet customer demand, which may necessitate temporary rotating outages,” said Juan Saca, the president of Luma Energy, in an announcement.

The blackout began at 5:30 a.m. on Tuesday, abruptly halting activities as residents prepared to celebrate the New Year. Investigations are ongoing to determine the exact cause of the incident, but initial reports from Luma Energy suggest that there was a failure in an underground electric line situated in the southern part of the territory.

Incoming Governor Jenniffer González Colón, who is set to take office soon, has warned that there may be further interruptions in service as power plants are not yet operating at full capacity. “During these days, I encourage everyone to moderate their energy consumption to minimize load fluctuations, enabling more residents to access electricity and assisting the system in restarting smoothly,” González Colón advised on the social media platform X.

During her campaign, González Colón promised to appoint an “energy czar” to supervise the management of the power grid, which has suffered for years from inadequate maintenance and poor infrastructure.

The electrical grid was severely impacted by Hurricane Maria in September 2017, a major Category 4 storm. Persistent issues with unreliable electricity remain a significant hindrance to daily life for many Puerto Ricans. In June, over 340,000 customers experienced power outages during a heatwave, and in August, at the height of Hurricane Ernesto, more than half of all utility customers lost power, with tens of thousands still without electricity a week post-storm.

This recent blackout comes as consumers prepare for an increase in electricity costs. Last month, the Puerto Rico Energy Bureau approved a rate hike of 2.2 cents per kilowatt-hour for residential customers, which will take effect from January to March, potentially raising the average household’s electric bill by nearly $20, according to the Energy Bureau.