Power Remains Out for Nearly Half a Million Customers in Puerto Rico

A day after an islandwide power failure struck Puerto Rico, in the latest breakdown of a perennially troubled electrical grid, nearly half a million customers remained in the dark Thursday night.

Power was being slowly restored, but more than 470,000 customers continued to lack electricity, out of a total of more than 1.4 million customers, according to poweroutage.us, which tracks power interruptions.

For Puerto Rico’s 3.2 million people, the islandwide loss of power was a frustrating continuation of hardships brought by an unreliable electric grid. The problems have persisted even after a private Canadian-American consortium, Luma, took over electricity transmission and distribution from Puerto Rico’s public utility last June with a pledge to reduce the frequency of outages.

Luma said in an announcement on Thursday that “the energy grid has suffered a massive island wide outage, potentially caused by a failed circuit breaker at Costa Sur power plant.” The facility produces the most electricity on the island.

Video footage circulating on social media showed a fire burning at one of the power substations in Costa Sur, on the island’s southeastern coast. The exact cause of the power failure, which occurred after 8 p.m. Eastern time on Wednesday, remained under investigation, Luma said in a statement Thursday. The company said there was “extensive damage” to the facility.

The Puerto Rico Electric Power Authority, known as PREPA, tweeted an image of the charred substation on Thursday, showing some of its components to be completely blackened.

Luma is “not in position to provide an estimate of full restoration at this time,” the company said in a statement Thursday afternoon. Efforts to restore power would continue into Friday, it said.

Public school was canceled on Thursday, and some government agencies paused their usual operations. An estimated 182,000 water and sewer customers — around 10 percent — were also without water on Thursday as a result of the blackout.

Gov. Pedro R. Pierluisi issued a series of updates on social media, urging people to “remain calm” and wait for official updates from government agencies and Luma.

In 2017, Hurricane Maria hit Puerto Rico, knocking out electricity across the entire island and further exposing the vulnerability of the already fragile power grid. Some residents were left without electricity for more than a year.

Officials have attributed past power failures to animals — one time a cat and in another instance an iguana, according to The Associated Press.

Last year, Puerto Rico privatized its electrical grid and awarded Luma a 15-year contract with an annual fee of $115 million to take over transmission and distribution operations from the beleaguered and bankrupt PREPA. The public utility is still involved in electricity generation.

When Luma took over, company officials said that they were prepared to handle emergencies and hurricanes. However, widespread blackouts have continued and have lasted longer than they did under PREPA.

Rafael Hernandez, the speaker of Puerto Rico’s House of Representatives, said in a tweet that a public corporation administered by Puerto Rican providers, like PREPA, could “work more effectively than the current energy system.” He called for Luma’s ouster, saying that there were “thousands of families suffering” from the outage.

Patricia Mazzei contributed reporting.