Dew-Collecting Greenhouse Grows Veggies in the Desert

Low-cost design could help farmers in Ethiopia maintain self-sufficient agriculture.

Technology news stories these days tend to lean toward hi-tech consumer gadgetry with cool features but rather limited utility, in the grand scheme of things. So sometimes it's nice to take a look at concepts that employ low technology in the service of genuine usefulness.

For instance, consider the dew-collecting greenhouse from Roots Up, a tiny non-profit operation affiliated with Ethiopia's University of Gondar. Designed for multifunction use, this low-tech, low-cost greenhouse could help farmers raise fresh vegetables, even under drought conditions.

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By trapping hot air and humidity in the mid-day sun, the greenhouse provides an improved atmosphere for plant growth. The greenhouse simultaneously works as a dew collector, capturing evaporation within the bio-plastic sheeting at the top of the dome.

When temperatures cool in the evening, farmers can pull a rope opening a latch at the top of the dome in such a way that water droplets cool and condense, falling into a collection cistern below. The collected water can then be used for drinking water or further irrigation.

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The greenhouse also works as a rainwater collector, and is intended to be a low-cost solution for Ethiopian farmers to maintain self-reliant farms in the area.

Roots Up hopes to deploy its first series of Dew Collector greenhouses in northern Ethiopia. You can read more about the initiative on the project page, or check out the short demonstration video below.

click to play video

More than 1.4 billion people around the world have no access to electricity. When the sun goes down, darkness comes up. Almost all of these people live in Africa and India. Kerosene generators are one solution, but they pollute the environment and are often too expensive for the millions of people living poverty. Those who rely on it go deeper into poverty just trying to read and work.

One innovation making its way into these regions is the solar-powered light bulb. Many of the newest models are comprised of a small solar panel, rechargeable batteries and an LED bulb, which requires very little energy to work.

Evan Mills, a scientist at Lawrence Berkeley National Laboratory hopes that solar light bulbs do for light-poor communities what mobile phones has already done for communities lacking a wired infrastructure. Mill thinks that solar light could leapfrog wealthy countries in acquiring advanced wireless LEDs and become ubiquitous. Beyond improving the environment, Mills said, "it will be a boon to literacy, safety for women and productivity of businesses who today are stuck with flame-based light."

Here is just a sampling of designs bringing solar-powered light to dark corners of the world.

The India-based company Greenlight Planet makes solar-powered lanterns called Sun King that are built to provide 16 hours of light from one day’s charge. Bright LEDs come mounted inside a waterproof orange lamp head incorporated into a supporting stand. When the Sun King lamps were rolled out in a rural Indian village several hours outside Mumbai, one elderly resident told the Wall Street Journal she was able to stop using a rusty kerosene lamp that made her cough.

The Denver-based solar light bulb company Nokero, short for “No Kerosene,” was started by mechanical engineer Steve Katsaros in 2010. Nokero’s solar light bulbs clearly resemble traditional light bulbs. Each bulb contains a rechargeable AA battery, LEDs under a curved housing, a small solar panel, and a hook to suspend it. Through international collaboration with NGOs, the company’s lights have been dispatched to areas worldwide. After a 2011 earthquake in Turkey, the bulbs provided light for millions without power.

Several years ago the young Kenyan engineer Evans Wadongo made it his mission to help bring Africans out of poverty. Kerosene lamps had damaged his vision growing up so he set to work designing a solar lamp he called Mwangabora, Swahili for “good light.” CNN named Wadongo one of the top 10 heroes for 2010 and he currently heads up the NGO Sustainable Development For All that works to bring lasting solutions to problems facing African families, including solar light.

The for-profit social enterprise D.light was cofounded by Stanford Design School classmates Sam Goldman and Ned Tozun. Their goal to serve households lacking electricity was inspired by Goldman’s experience as a Peace Corps volunteer in Benin, where a kerosene lamp burned his neighbor’s son.

D.light makes several bright orange solar lights that include a circular, tilting LED mounted on a simple metal stand, a wide bottle-shaped light with a multi-setting handle, and a dual-purpose light and phone charger with a strap attachment and rounded handle.

Belgian designer Alain Gilles developed the Nomad portable solar lamp system for O’Sun that could both be used in place of kerosene and work as a camping or outdoor lamp. The light was presented earlier last year at Milan Design Week, where the simple lantern gained attention for its shock resistance, hook attachment for suspension and mobile phone charger. The waterproof lantern has three settings, allowing it to get between six and 35 hours depending on the mode following a six-hour charge. If the sun fails, Nomad can be recharged in a car or wall outlet.

LuminAID cofounders Anna Stork and Andrea Sreshta met in graduate school, where they were studying design and architecture. After experiencing the 2011 earthquake in Japan firsthand on a trip, they developed a portable, inflatable and water-resistant light that only weighs three ounces and packs down so that 50 could be shipped in the same box that only holds eight regular flashlights. A five-hour charge gives LuminAID between about six and eight hours of diffused LED light, and has two brightness settings.

Former Marine and American Diplomatic Corps member Mark Bent started the company SunNight Solar in 2006 to produce a durable flashlight-shaped solar light called BoGo. Bent uses rechargeable batteries that run for between 750 and 1,000 individual nights with between six and eight hours of usage with LEDs built to last an average of 100,000 hours.

BoGo lights have been donated through nonprofits to communities across the world, including Africa and India. Last year when Hurricane Sandy caught Bent on the road and the hotel where he was staying lost power, he distributed lights to guests.

The New York City-based company Mpowerd, led by entrepreneur Jacques-Philippe Piverger, recently came out with its own version of an inflatable solar lantern known as Luci. Piverger initially got help from the crowd-funding site Indiegogo to create the light. Each four-ounce cylindrical lantern produces six to 12 hours of light after six hours charge time. Mpowerd calls its solar-powered light a combination task light, flashlight, and diffused lantern.