

In rural regions of the Himalayas, a new lightweight, low cost, portable solar cooker called the SolSource 3-in-1 is poised to transform the health and prosperity of entire villages. The device, which can replace the hazardous traditional biomass-burning stove as a means for cooking and heating the home, can also use its own waste thermal energy to generate enough electricity to light a home at night, charge cell phones and power other small devices. And because the cooker's unique design targets specific local needs and materials, its manufacture and distribution could provide a new economic future for communities in transition from agricultural to manufacturing economies.
The satellite dish-shaped SolSource, developed by US-based nonprofit One Earth Designs, is elegant in its simplicity. Reflective nomadic tent material, stretched across a bamboo frame, concentrates sunlight from a large area inward toward a focal point where the user can place a pot stand for cooking, a thermoelectric device for generating electricity (at a lower cost than a photovoltaic panel), a heat module for heating the home, a solar water disinfector for treating drinking water, or a thermal battery for cooking after dark. These interchangeable parts are each about the size of a laptop computer, and the main platform is easily folded and disassembled for portability.
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Powers and co-founder/CEO Scot Frank, both 23, and project chief engineer Amy Qian, 20, worked with Himalayan university students to collect direct feedback from villagers across the region to inform the design of the SolSource 3-in-1. Crowd-sourcing input on the design was particularly important to this project, because although the villagers were already familiar with solar cookstoves introduced throughout the region via various government and NGO initiatives, these devices weren't fulfilling the nomadic communities' unique needs.
"In many cases, the villagers and nomads are quite disappointed with the current solar cookers available," says Frank. Many of these stoves, he explains, are made from concrete and glass components, both of which are easily broken during distribution and everyday use, yet the rural communities lack the expertise and tools needed to repair broken devices. The stoves, which weigh about 95 kg, aren't easily portable, so they hinder the villagers' traditional lifestyles. And the stoves are designed for cooking only, so the villagers still rely on biomass burning to heat their homes, a need that accounts for most of the region's fuel use.
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"People are very concerned about what they will use for fuel in the future," says Powers.
The region is also suffering economically. As nomadic life becomes more difficult, villagers are increasingly migrating to urban centers. In China, government initiatives encourage this transition, but in both China and India, rural villagers arrive in cities without the language and job skills necessary to enter the urban workforce. As a result, families get trapped in a spiral of poverty.
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The community-based plan also allows villagers to leverage their traditional group decision-making process. “Traditionally, Himalayan nomads and agriculturalists made many decisions collectively and often relied on neighboring households for food and goods production,” Powers says. “The SolSource Project supports local income generation through a holistic community-based business model that more closely reflects this traditional collectivism.”
Earlier this month One Earth Designs was awarded the prestigious St. Andrews Prize for the Environment (the SolSource 3-in-1 is also the recipient of the Muhammad Yunus Innovation Challenge Award, the MIT IDEAS competition, and a Clinton Global Initiative Outstanding Commitment Award.) The $75,000 St. Andrews Prize will fund a pilot program this summer to test their business plan in West China.
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One Earth Designs is committed to helping rural Himalayan populations achieve appropriate science- and technology-based solutions for living more sustainably. In addition to other devices for providing energy and clean water to these regions, Powers and Frank have initiated a textbook project with the goal of distributing educational materials that explain science and engineering principles in local Himalayan languages, using familiar examples and illustrations.
“The Himalayan terrain is one of the harshest on Earth and its people have an incredible history of innovation,” says Powers. “With our applied science and engineering education projects, we are hoping to re-inspire pride and excitement in young people about this rich technological history and to help people feel confident about pursuing careers as inventors and scientists whether alongside agrarian occupations or as a sole pursuit.”
Read related articles in the Worldchanging archives:
Earth Day: 10 Big, Really Hard Things We Can Do to Save the Planet
MicroEnergy Credits Corporation: Greening the Base of the Pyramid
Wow, that's great. Inspirational design there.
How can 15 Watt hours run lights for seven hours (see paragraph 3)? A 15W CFL seems like the minimum amount of light for one room, but this would only run for one hour, not seven. Surely this couldn't provide any useable amount of home heating? A typo? 150W, perhaps?
The cooker itself seems to be a great idea. Solar cookers like these are also brilliant for providing safe drinking water by pasteurizing it — contrary to popular belief, boiling is not necessary. My guess is that this, and the many similar designs, have a bright future.
That's correct if you are working with CFLs, but LEDs can run on much lower wattage. In a village, the biggest lighting need would probably be for school children trying to study at night. This only requires lighting within a small area. An LED set up like this, for example, would run for 7 hours: http://www.meritline.com/18-led-2w-spotlight-321---p-23958.aspx
Ah, true. Thanks Kristen. LEDs would work for that, but I remain unconvinced about the direct contribution to heating although wood/dung not used for cooking would become available for heating. However, whether that would result in a reduction in the amount of wood/dung used, or simply in warmer homes (as the more abundant fuel was burned) remains to be tested.
Pete - We have two different heating modules that run off of heat transfer fluid and phase change materials. They do not involve electricity as this would be inefficient.
Kristen - We are indeed using LEDs which are very reasonably priced in local wholesale markets.
What I like about this team is that they have every traditional credential to boast about coming up with the ideal design on their own. INSTEAD, they double up on distributed approaches:
Distributed Energy derived from distributed innovation. Is it perfect? No...I'm concerned about how they can make sure their design responds to one culture over another. Do they seem to have the design flexibility to address this? It definitely looks like it!
Cooking is one of the hardest appropriate technologies to crack, but if they make a dent, it will help a lot of people.
Thanks Catlin. I'll look forward to hearing more about it. Congratulations.
This is amazing! Although I do not know much information about the culture or solar cooking/energy, I feel like this project can make a huge impact! Keep up all the good work!
I am excited to see how everything plays out!
Awesome!
I'd like to see more discussion on the 15-watt hours/day. In these Tibetan areas there's something like 5,000 watt-hrs/m^2 of sunlight insolation. 15 watt-hours per day is what a 3-watt solar panel would produce under these conditions. Solar electric LED lanterns with only 10 watts of PV are generally inadequate in many locations for domestic lighting.
Chris, these are good points to discuss. To expand on information provided in the article, I would like to add:
1) The amount of light produced by a light source depends on the lumen/watt ratio of the lights in use (LED>CFL>incandescent). It does NOT depend on the wattage of the charging device or battery powering the light.
2) For a rural home (in the communities we are working most are one room), only a small area needs to be lit and often people only want lighting for specific tasks, such as reading or finishing chores. Low-watt LED lighting works well for this. In addition, if people don't need seven or more hours of continuous lighting, they can power multiple LEDs simultaneously to produce a greater amount of lighting.
3) The amount of thermal-generated electricity depends on weather, temperature gradients, and usage patterns. 15 wh/day is a conservative estimate of the electrical output of this device (assuming one hour of use and less than average solar irradiance).
4) More electricity will be generated on a day with average sunlight and people can further increase the amount of electricity they generate by leaving the module on the concentrator for more than one hour per day. By increasing the size of the module, more electricity would also be generated.
Thank you for bringing up these questions. We'd love to have both suggestions and collaboration in order to improve the design.
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Congratulations to the One Earth Desings team for creating such a life-changing device! You've successfully tackled complex engineering and socio-economic problems and gathered global interest in a project that solves energy problems in both developing and developed countries.
A old-timey capitalist question: 'does it scale?' How does increasing the surface area of the reflector affect energy capture? On the production side, does a larger SolSource lead to lower manufacturing costs? At larger scale, how do additional resources provided by SolSource even appeal to rural villagers?
Completely off topic, how much has OED looked into the SolSource as an aid to disaster-relief? For example, after a catastrophe, could earthquake prone areas benefit from SolSource for clean drinking water and (some) electricity until those utilities are restored?
To answer your questions: (1) increased size = increased power capture, (2) increased size does not lower manufacture costs, but it would improve the energy capture/labor ratio. The drawbacks would be decreased portability and wind sturdiness. (3) I don't understand your third question, (4) the SolSource 3-in-1 might be a very good option for some disaster-relief situations. We do not yet have the capacity for this on our own, but would be happy to partner with disaster-relief organizations in this regard.
where can you find plans to build this system?
Quick point: The Creative Commons Developing Nations license has been retired, yes. But that doesn't mean you can't use it anymore. It's just hidden.
http://creativecommons.org/licenses/devnations/2.0/
They decided that there wasn't sufficient demand for the license, and that the licenses they wanted to support should allow at least for worldwide, verbatim sharing (which the DevNations license doesn't do). But the retirement of the license doesn't stop anyone from using it.
@dschainker: Quick point regarding scaling. Since these devices are usually at ground level, and often left unattended where children can put a hand in the focus, scaling the product to concentrate two or three times the energy could have highly negative consequences. At current scale, they pose about the same danger as a hot stove.
On the other hand, you could mount a larger one on a ten foot pole, or otherwise put it out of reach.
@Zoltan
For instructions and plans on how to build the SolSource, please contact us. Currently, the device's construction is adapted for the Himalayan region. We are interested in working with others to make it using locally sourced materials around the world. We'd love to have your help in this.
@Bryce
Thanks for the reference to this DevNations license! We'll look into it going forward.
Hey guys what are you using for thermo-electric converter that is more cost effective than PV?
Last i checked (about 2 years ago) thermo-el. was pricier than PV, and PV costs have come down since then.
Also congrats on appropriately deployed, appropriate design ;)
We are interested in adapting this system for the northbay area outside of San Francisco! I want to hear more about how to test and obtain one of these!
Thank you for your brilliance!
@Dex - Good question about PV. In W. China, local prices for a 4W solar panel outfit are around $40 USD. Considering most rural people's electricity needs, this is not as cost effective as thermal-electric. Similarly, we've found solar panels in India (many sourced over the border from China) to be just as expensive.
@Pixie - Thank you for your interest! We're excited to re-connect in the Bay Area where many of us hail from. If you or others would like to discuss obtaining a SolSource 3-in-1 for your own use, please contact us and we will follow-up with you individually:
http://www.OneEarthDesigns.org/contact

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