Zero Mass Water, a sustainable water startup, is trying to create an easy, off-grid way for anyone to harvest that liquid with its first product, Source.

You want to make sure that these materials that are going to passively absorb water from the air hold onto that water strongly enough that they’ll do so under dry conditions, but not so strongly that under any condition it takes lot of energy to get that water back off,” he says.

Because of the device depends on solar power, he says, that number doesn’t vary too drastically between dry and wet climates solar radiation is stronger in dry places where there are fewer water molecules in the air to absorb it, and water vapor is more prevalent in wet places where solar radiation is less intense.

Zero Mass Water boasts that one Source is able to produce enough clean drinking water each day to satisfy a family of four; however if all four members followed the 8-glasses-per-day rule, that family would wind up about 3 liters short.

When that happens, Zero Mass Water programs one to act as the hub, and when that hub uses up the water in its reservoir, it can communicate with the other panels, which act as spokes and sent their water over.

Duke Energy has installed panels in schools, homes, and a clinic in Ecuador, and the Zero Mass Water earned a US AID grant to deploy panels to refugee camps in Jordan and Lebanon.

Zero Mass Water’s products seem especially promising for emergency situations, since they are 100% sustainable and don’t require and electrical inputs.