It’s a befuddling equation, but it’s at the heart of a new solar hydropanel developed by Arizona-based startup Zero Mass Water.

The company’s SOURCE panels can be installed atop any building just like standard photovoltaics, but instead of just harvesting solar energy, they use the sun’s rays to pull water from the air.

Each panel has the potential to draw up to 10 liters of water per day.

From there, the water can be siphoned directly to a drinking tap.

Zero Mass Water says that even low-humidity and arid regions can effectively benefit.

“Our array on the Zero Mass Water headquarters in Scottsdale, Arizona makes water year-long despite low relative humidity. The Phoenix-Metro area can get below 5% relative humidity in the summer, and SOURCE still produces water in these incredibly dry conditions,” he said.

Additional panels can also be added to optimize water collection, but there is the matter of cost.