When Hurricane Maria battered Puerto Rico and decimated the Caribbean island's power grid five years ago, the lights stayed on in one building in the mountain town of Adjuntas.

The Casa Pueblo environmental group had equipped its Adjuntas headquarters with solar panels and storage batteries — a model of green self-sufficiency that inspired the organization to launch a pioneering community-run microgrid in the town.

"We want to democratize the generation of energy ... we're pushing from the bottom up," said Arturo Massol-Deya, who heads Casa Pueblo, which last month finished installing nearly 700 rooftop solar panels as part of the microgrid initiative.