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SolSource 3-in-1: An Alternative Energy Solution
Julia Levitt, 29 May 09


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.

Photo source: One Earth Designs
The SolSource generates enough heat at its focal point to bring a kettle of water to boil in about five to seven minutes – about the same amount of time as conventional gas stoves in homes throughout the developed world. While it is in use, the device generates heat to warm the home, and can create and store about 15 watt hours of electricity, or enough to power the lights for about seven hours. This is adequate for the villagers' needs, but upgrading to a larger thermoelectric device would easily increase the energy capacity, says One Earth Designs co-founder and COO Catlin Powers.

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.

A woman uses a traditional biomass-burning stove
Photo source: One Earth Designs
In traditional rural communities around the world, the need for a safer, more efficient cooking and heating device has long been a pressing one because of the high incidence of lung diseases – primarily in women -- caused by indoor air pollution from the traditional cookstoves. But in these remote, high-altitude regions of China and India, the impacts of climate change and the demands of a growing population have exacerbated the stress on local fuel supplies, touching off a string of other related problems. For example, when they remove too much animal dung, the primary biomass fuel, from the fields, villagers must apply chemical fertilizers to their crops to replace the nutrients that manure would have supplied (the dung, which local women collect by hand, is also a primary vector for pathogen transmission). When they burn crop residue, a secondary fuel source, villagers deprive themselves of a valuable source of feed for their livestock. Deforestation has made wood a scarce commodity, and in many regions collecting it for fuel is now illegal. And climate change has forced the pika, a small grassland animal, to migrate to higher and higher altitudes in search of food, where its grazing destroys the grasslands and kills off the small bushes that were once another main source of fuel for nomads.

"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.

Scot Frank, Catlin Powers and Amy Qian with the SolSource
Photo source: One Earth Designs
One Earth Designs' business plan for the SolSource Project, Powers explains, plays to the strengths of these resettled populations. Though the devices are made largely from traditional nomadic materials, components such as metal must be sourced in cities. Communities in transition are in an ideal position, then, to combine traditional materials and skills with urban materials in order to build the SolSource, and the common language they share with rural populations makes them competitive salespeople in a niche market. The profits they earn will enable them to send their children to school and break the cycle of poverty.

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.

One Earth Designs COO Catlin Powers displays the St. Andrews Prize for the Environment
Photo source:
International interest, however, is already outpacing production capacity. The innovative design has garnered inquiries from a variety of groups and individuals around the globe, from government departments to other humanitarian organizations, to Americans who want to use the devices for off-grid living or camping trips. Though One Earth Designs isn't yet prepared to produce the units for large-scale distribution, Powers and Frank hope to see that change. They are seeking a customized patent option that would allow them to protect the design from competitors in the developed world where sales of the SolSource at a profit could subsidize its manufacture and distribution in disadvantaged regions, but they intend to make the design openly available to innovators in the Global South who could adapt it to suit the needs of their own regions (the Creative Commons Developing Nations License once offered a solution like this, but it has since been retired).

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:

Cardboard Cooker Wins $75,000

Earth Day: 10 Big, Really Hard Things We Can Do to Save the Planet

Sustainable Cooking Stoves

MicroEnergy Credits Corporation: Greening the Base of the Pyramid

Un-Electric Fridge

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Wow, that's great. Inspirational design there.

Posted by: Scatter on 26 May 09

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.

Posted by: pohanginapete on 26 May 09

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:

Posted by: Kristen Downs on 26 May 09

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.

Posted by: pohanginapete on 26 May 09

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.

Posted by: Catlin on 26 May 09

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.

Posted by: Jgomezm on 26 May 09

Thanks Catlin. I'll look forward to hearing more about it. Congratulations.

Posted by: pohanginapete on 26 May 09

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!

Posted by: Ajmcil2 on 26 May 09


Posted by: Andy Lubershane on 27 May 09

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.

Posted by: Chris Greacen on 28 May 09

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.

Posted by: Scot Frank on 28 May 09

Hey people i make a ad to help poor people from climate change!... see the video and send it to all the people you know, together we can press the world leaders. See the video and send please!!! this is the link: (give 5 stars) together we can help!!

Posted by: David on 29 May 09

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?

Posted by: dschainker on 29 May 09

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.

Posted by: Scot Frank on 29 May 09

where can you find plans to build this system?

Posted by: zoltan strigan on 30 May 09

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.

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.

Posted by: Bryce on 2 Jun 09

@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.

Posted by: Bryce on 2 Jun 09

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.

Thanks for the reference to this DevNations license! We'll look into it going forward.

Posted by: Scot Frank on 2 Jun 09

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 ;)

Posted by: Dex on 5 Jun 09

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!

Posted by: pixie on 15 Jun 09

@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:

Posted by: Scot Frank on 26 Jun 09

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