The slow pace of restoring electricity to residents of Puerto Rico is making off-grid solar-plus-storage an appealing alternative.

A recent report posted at Greentech Media focused on the remote mountain community of Orocovis, which has been without a working power grid since Hurricane Maria ravaged the island more than four months ago. The U.S. Army Corps of Engineers predicts the grid may not be repaired for two or three months, and in the meantime many residents are relying on generators for electricity.

Yet thanks to the efforts of battery manufacturer Sonnen and solar installer Pura Energía, the local school has two solar-plus-storage systems with enough capacity to run computers, provide refrigeration in the school’s kitchens, and give the 150 students light for getting their homework done. The system consists of a 15 kilowatt solar array and two batteries.

What’s key is that even after the Puerto Rico Electric Power Authority (PREPA) manages to reconnect Orocovis to a rebuilt grid, assuming it does, the school will continue running on its own power, says Alberto Melendez Castillo, director of the S.U. Matrullas school. With the addition of a water collection and purification system, the school would be able to stay running in the event of another disastrous storm.

Castillo says the prospect of cheaper electricity, not a distrust of the utility or the government, is the reason for planning to stay off the grid in the future — a pattern seen elsewhere across the island.

Power is slow to come back

The massive hurricane struck Puerto Rico last September as a Category 4 hurricane. Last week, nearly five months later, the U.S. Department of Energy said power had been restored to about 77% of PREPA customers. That leaves some 343,000 customers still without electricity unless they had a generator or, like the school in Orocovis, a photovoltaic installation.

The slow pace of reconstruction has altered how people view solar-plus-storage systems, Greentech Media said, transforming the option from an expensive oddity into something that is widely understood, and sought after.

Adam Gentner, director of business development and Latin American expansion at Sonnen, said: “One thing I hear from every partner down here is that before the hurricanes, you always had to explain the value of solar and solar-powered off-grid backup systems to people. You had to explain why you would spend money on this, and why you need it, and what it does for you. Now, you don’t have to explain that to anyone in Puerto Rico.”

Sonnen is a German manufacturer that began production in Atlanta last year as part of an expansion in the U.S. Puerto Rico also has been aided by Tesla, which late last year said it would install a number of solar-and-battery systems on the island, including a large one at a children’s hospital in San Juan, as a temporary fix while the grid was repaired.

Whether solar-powered microgrids can become a permanent replacement for a conventional power grid on Puerto Rico is debatable, in part because of political and financial concerns, an article at Renewable Energy World said. Both the island government and PREPA are heavily in debt; on Monday, Bloomberg News said PREPA warns the utility may begin shutting down unless it gets a $1 billion loan from the government.

Solar-plus-storage systems may not be a universal solution to the island’s grid problems. But they have made a big difference in communities like Orocovis where they have successfully been installed.

“The solar microgrid has had a very important impact on the community,” school director Castillo told Bloomberg. “It has been very moving to see the students drinking cold water, eating fresh food and being able to work on computers powered by renewable energy.”