30 Years Off the Grid

A couple in the Tucson Mountains has lived off the grid for over 30 years, and their updated account offers a real-world look at how solar power, batteries, and water systems have improved since the 1980s. Their house uses thick insulation, concrete block walls, and steel roll-up shutters to manage desert heat, along with a shaded courtyard and careful window placement to limit afternoon sun. These passive design choices have needed no maintenance over three decades.

On the power side, they started with a 5kW solar array and lead-acid batteries that had to be hand-watered and couldn't be drained past 50 percent. They've since upgraded twice, and their current 13.5kW solar array with a 50kWh lithium battery system runs the house, including efficient ductless heat pumps (called minisplits) for heating and cooling, without the buzzing power quality or generator backup they once needed. Panel costs have dropped sharply, from $25 a watt in 1988 to $0.40 a watt for their most recent addition.

Water has been the bigger challenge, since their well never found water. They still haul in water regularly, but switching from evaporative cooling to minisplits cut their weekly water use roughly in half. They also added a hot-water recirculation system, which sends cooled water in the pipes back to the heater instead of down the drain, a low-cost upgrade that works in any home, not just an off-grid one. They dropped solar water heating altogether, finding modern propane tankless and heat-pump water heaters more practical.