SAN JUAN, Puerto Rico (AP) — Puerto Rico’s governor announced Friday that the US government has shipped three mega generators to the island to help stabilise the US territory’s rickety electric grid and minimise continuing outages.

The generators will add 150 megawatts of power, and additional generators that the US is expected to ship soon will supply another 250 megawatts, Governor Pedro Pierluisi said.

Officials said crews will install the generators before the start of the Atlantic hurricane season on June 1.

“It’s the first step in a very, very complex process,” said Nancy Casper, a coordinator with the US Federal Emergency Management Agency.

FEMA is paying for 90 per cent of the project and Puerto Rico’s government the remaining 10 per cent as part of a deal reached last year, but both Casper and Pierluisi said the total cost was not yet available because it would depend in part on how long the generators will operate.

Puerto Rico only recently started permanent repairs on an aging power grid razed by Hurricane Maria, a Category 4 storm that struck the island in September 2017. Since then, power outages have become a common occurrence, disrupting daily life on the island of 3.2 million people.

The federal government has allocated some $12 billion — most of it for the grid reconstruction — but only 18 permanent projects totalling $88 million have been completed as of early March, according to the nonpartisan think tank Centre for a New Economy.

“At this pace, it would take over 100 years to complete the reconstruction of the Puerto Rico electric grid,” the centre said in an analysis published Thursday.

The power grid was further weakened by Hurricane Fiona, a Category 1 storm that hit Puerto Rico’s southwest region in September 2022. It sparked an island-wide blackout and caused more than $3 billion in damage to the crumbling electric system.

“The temporary generation is critical,” Casper said of the new generators.

The temporary power boost will allow crews to take substations, transformers and breakers offline for repairs that could take anywhere from 12 to 18 months.

Puerto Rico’s power grid was already shaky before Hurricane Maria struck, with officials blaming decades of mismanagement and neglect. Its generation units are on average 45 years old, twice those of the US mainland.

The grid’s ongoing problems come as Puerto Rico’s Electric Power Authority struggles to restructure more than $9 billion in debt, the largest of any government agency. A majority of creditors have yet to reach a deal with a federal control board overseeing the island’s finances despite six years of acrimonious negotiations.

In June 2020, the island’s power company privatised transmission and distribution operations, and in January, it announced that it had selected a private company to operate and maintain its generation units.