Puerto Rico has no oil, no gas and no coal of its own, and no pipeline to anywhere. Every drop of fuel its power plants burn arrives by ship. That is the fact underneath everything else on this page — including why, over the past eight years, a few hundred thousand households quietly built a second power system on their own roofs.
September 2017
Hurricane María took the whole grid down. Not part of it — all of it. A US grid, run under US regulators, rebuilt with federal disaster money, and the last customers still waited about eleven months to get their power back. It remains the longest blackout in American history. The island had one big centralized system fed by imported fuel, and when it broke there was nothing underneath it.
Except in one mountain town.
The town that kept its lights on
Adjuntas sits in the central mountains, about 18,000 people. There is a community group there called Casa Pueblo, started in 1980 by locals fighting a proposed open-pit mine. They won, and then they kept going. In 1999 they put solar panels on their own roof, which at the time was mostly a statement. In the months before María they finished taking the building off the grid entirely.
So when the storm passed and the island went black, Casa Pueblo had power. It became the place you went. People charged phones there, ran dialysis machines, kept insulin cold in solar-powered refrigerators. The group handed out 14,000 solar lamps to households that had nothing at all. A small nonprofit in the mountains was, for a while, functioning infrastructure.
Arturo Massol Deyá, who leads the group, started calling what came next an energy insurrection.
What came next was the first community-owned microgrid on the island — a microgrid being a small power system that can keep running on its own when the big grid fails. Two million dollars, 700 panels across seven buildings, two half-megawatt batteries, wired into fourteen businesses on the town square: the pharmacy, the hardware store, the bakery, the pizza place. It sells them power, and the proceeds pay to put solar on the roofs of neighbors who cannot afford it. In January 2026 Casa Pueblo connected its two microgrids together, which its leadership called a first for the Caribbean and Latin America. There are now more than two thousand solar modules around the municipality, including a solar-powered cinema and the community radio station.
Then the rest of the island did it, one roof at a time
Not because of a program. Because power costs the average household here about 8% of its income, against 2.4% on the mainland, and because the lights kept going out anyway.
By the end of 2025 Puerto Rico had 191,929 rooftop solar systems totaling about 1,456 megawatts — roughly a fifth of all generating capacity on the island, second only to natural gas. 171,000 of those homes and businesses also installed batteries. Between 2016 and 2025, distributed solar accounted for 81% of every scrap of new generating capacity added. Through 2025, people were putting up about 3,850 systems a month.
The day 70,000 home batteries ran the grid
All those batteries got wired together into what is called a virtual power plant — meaning the grid operator can reach into tens of thousands of private home batteries at once, draw a little from each, and treat the whole thing as if it were a power station. Puerto Rico’s runs about 70,000 batteries and can deliver roughly 48 megawatts on call. Homeowners are paid around $200 a battery a year to take part.
On July 9, 2025, the grid operator was short nearly 50 megawatts and heading for rolling blackouts. It pulled from the home batteries instead, and nobody lost power. For that afternoon the island was running partly on its own living rooms.
One footnote worth knowing: the official figures still say Puerto Rico’s electricity is about 97% fossil-fueled, and that is true of the grid — roughly 47% natural gas, 34% oil, 17% coal. But rooftop power never passes through a utility meter, so it does not appear in those numbers at all. The island is further along than its own statistics show.
The dome on the point
This was not the first attempt to get off imported fuel. Drive out to Rincón on the west coast and there is a concrete dome sitting on the headland above the surf, 190 feet across, next to the Punta Higüero lighthouse.
That is BONUS — the Boiling Nuclear Superheater reactor, the only one of its kind ever built. Construction started in 1960. It went critical on April 13, 1964 and reached full power in September 1965. The idea was to superheat the steam inside the reactor itself and push efficiency high enough to beat oil. It ran until June 1968, when technical trouble and the cost of fixing it ended the experiment after less than three years of full operation.
The reactor was entombed in concrete and grout and the vessel is still inside. So is the control room, preserved as it was. The beach below is named Domes after it, and it is one of the best-known surf breaks on the island — people have been paddling out underneath a decommissioned nuclear reactor for fifty years without much thinking about it.
Sixty years apart, two swings at the same problem. One was a federal experiment that lasted four years and left a monument. The other was a few hundred thousand people buying panels.
Where to see it for yourself
Casa Pueblo, Adjuntas
The one place you can actually walk into the story. It is a restored house on Route 123 just off the town plaza, open 8:30am to 3:30pm seven days a week, with a suggested donation of about $2. Half an hour covers it: the museum rooms, the shop, the butterfly garden, the radio station, and their own Madre Isla coffee, grown locally and roasted on site. It is run largely by volunteers, so calling ahead is smart — 787-829-4842. Step back out onto the square and the solar panels on the surrounding businesses are the microgrid.
Adjuntas is about a two-hour drive from San Juan: PR-22 west to Arecibo, then PR-10 south through Utuado. The mountain half of that route is slower than the map suggests.
Domes Beach, Rincón
The dome is plainly visible from the beach and the lighthouse park beside it, and the whole headland is worth the stop anyway — it is a prime spot for watching winter surf and, in season, humpback whales offshore. Be clear on one thing before you go: the museum inside the dome is managed by the US Department of Energy and is not regularly open to the public, so treat this as a landmark you look at, not a tour you take. Rincón is close to a three-hour drive from San Juan.
Everywhere else
Honestly, look at the roofs. Take the window seat on the way in and look down as the plane comes over the metro area, or just watch the houses go by on any highway. Once you know what you are looking at, the second power system is impossible to miss.
Fitting it into a trip
Neither of these works on a cruise port day — Adjuntas and Rincón are both half-day drives from the pier before you have seen anything. This is extra-days territory. If you are adding nights before or after the ship, see our Puerto Rico itineraries, or start with the trip planner to work out how many days you actually have. For getting out of San Juan under your own steam, see getting around Puerto Rico. And if your question is the practical one — what actually happens if the power goes out while you are here — see Puerto Rico power outages: what visitors need to know.
