When Hurricane Irma scraped its way up the Florida peninsula, it left the state’s electrical grid in pieces. Between 7 million and 10 million people lost power during the storm — as much as half of the state — and some vulnerable residents lost their lives in the sweltering days that followed. Meanwhile, tens of thousands of electrical workers from around the country rushed to the Sunshine State to repair damaged substations, utility poles, and transmission lines.

But in Palm Coast, on Florida’s eastern seaboard, midway between Daytona and St. Augustine, Jim Walden never lost power. As he and his wife listened to debris clattering off their roof, 24 solar panels and 10 kilowatt hours of battery storage kept their lights on and their refrigerator cool. Over the ensuing days, as electric utilities struggled to return power to Florida’s storm-wracked communities, the only thing Walden and his wife missed was their air conditioner (which would have drained their batteries too quickly).

“It worked flawlessly,” Walden says of his solar-plus-storage system. “We had plenty of power for the fans to keep us cool and the lights when you walk into the bathroom at night. The wife would even run her hairdryer off of it.”