This Dew-Harvesting Greenhouse Waters Itself–And Then Makes Clean Drinking Water

Grow kale and flowers, get drinking water in return.

In parts of Ethiopia, it often doesn’t rain for six months in a row, and growing food is a perpetual struggle. A new greenhouse is designed to harvest dew so farmers don’t need to rely on outside water supplies.


During the day, as temperatures rise outside, the heat makes water evaporate from the plants inside the greenhouse. At the end of the day, the farmer opens a flap on the top of the building, and the water condenses into dew and rolls back into a collection tank.

“The water harvested will be enough for the plants inside the greenhouse, since we will also develop water conservation practices which are very simple and available for farmers,” says Mathilde Richelet, cofounder of Roots Up, the organization that designed the greenhouse.

The organization plans to work with farmers to help them grow a rotation of crops like lentils and kale, along with herbs and flowers that can help repel pests. As the plants grow, the farmers will also be able to drink the extra water that the greenhouses produce.

“People have access to very little drinking water all year long,” says Richelet. “They have a long way to the river, which is practically dry during the dry season, and this water has a very high level of turbidity. So the dew-collector greenhouse has several purposes. First, it will allow farmers to collect the appropriate amount of safe drinking water needed for the body a day. Then, farmers can irrigate their plants.”

By making it easier to grow food, Roots Up hopes that farmers will be able to eat a bigger variety of more nutritious food, and make more money as yields improve.

The designers are raising funds on Indiegogo to build a demonstration greenhouse. Next door, they’ll build an “ecodome”–a small building made from soil–where they plan to offer agricultural classes with a local university.

About the author

Adele Peters is a staff writer at Fast Company who focuses on solutions to some of the world's largest problems, from climate change to homelessness. Previously, she worked with GOOD, BioLite, and the Sustainable Products and Solutions program at UC Berkeley.