Burning Questions: Rocket Stoves as Fuel for Innovation

Smokey, indoor, earthen-stove constructs and open fires have filled the stomachs of Shipibo for generations. But lately this way of life is changing. As the firewood-generating forests of their grandparents dwindle, replaced by grassy farmland, these fires become harder to feed. A conversion to expensive propane (and external reliance) is already taking place, but what if a healthier, more efficient wood-burning stove could be made available? Alianza Arkana has given me a shot at coming up with a solution to these problems.

The Design Challenge

I’ve spent the last few months designing and tweaking prototype earthen stoves and ovens at the permaculture site being developed on Alianza Arkana’s office grounds that will be replicated throughout various partner communities.

The design parameters:
• Increased efficiency
• Reduced negative health impacts of cooking (irritated eyes, respiratory illnesses, etc.)
• Culturally-accessible and -integrative (easily adoptable, built with local materials, affordable, sustainable, and replicable)

Rocket StoveMy starting point was a very simple, pre-existing “improved stove” design made from rocks and earth. Easy? Well, I quickly discovered there is a world of variations and technical information surrounding the design of an effective stove, one important factor being that a stove made from a thermal mass (i.e. rocks and compacted earth), as opposed to an insulating material, will have reduced efficiency. Further research was necessary…

Browsing the design possibilities, a technological theme emerged: the rocket stove. The L-shape combustion chamber can be simply constructed in a multitude of ways and is designed to burn wood as hot as possible. A hot fire ensures much more of the wood’s energy is consistently converted into useful heat while reducing toxic emissions.

Once again, the wormhole deepened as a whole world of rocket design options unfolded in front of me. Weeding through the stoves, I selected a few that I thought could be feasibly built with the local materials and fit the other criteria.

In the past I have worked closely with experienced traditional and natural builders and this has taught me a huge range of transferrable skills. Although I was given many responsibilities in various stages of those projects, project coordination and critical decision-making were never part of my job description. Stagnating and uncertain I was quickly becoming overwhelmed with information and feeling distinctly inexperienced to make quality decisions. I realized I needed help.

Leading Natural Building Experts Extend A Hand

Rocket ovenThe Aprovecho Research Centre,”dedicated to researching, developing, and disseminating clean cook-stove technologies,” had gotten me this far in the game with their virtual resources and shared experiences. So, I reached out via email and unexpectedly got connected with the leaders in the field. The wealth of knowledge, experience, and support since imparted by Aprovecho’s Larry Winiarski and Jon & Flip Anderson and Alianza Arkana’s Shipibo permaculture specialist, Marcos Urquia, has been invaluable (Thank you, guys!). My confidence has grown with time as I have gratefully made the most of the existing support structures, tried my best, and taken it all step by step so as to not get too stymied by the big picture.

Since constructing various oven and stove designs on Alianza Arkana’s office site, I have had numerous local allies and institutions request rocket ovens and stoves for their own demonstrations sites. This week I led a workshop at the Kuka Ethnobotanical Garden to teach leaders from the Network of Amazonian Indigenous Permaculturalists (RIPA) to collaboratively build some of the region’s first earth ovens.

Observations on Culturally-Appropriate Earth Ovens

The Shipibo from RIPA were accompanied by Alianza Arkana staff and volunteers, who were all keen to learn about simple natural building techniques. The Shipibo, who come from a rich tradition of making ceramics, had lots of ideas about how to improve the recipe for the earth mixture by adding ash from the Cecropia tree and using a local white clay, both of which they say Shipibo women use to make their ceramics more durable.

Natural Builders

They also expressed concern that many Shipibo women like to get their fires raging hot, using lots of wood so that the flames are higher than the pot they are cooking with. “It will be hard to change their custom of cooking on a hot open fire, but I think once they see how hot these rocket stoves can get with just a small flame, and once they see that the firewood which would normally last only for one meal could last for many days or even a week, they will begin to be much more interested in adopting this technology,” said Marcos Urquia.

We are only just scratching the surface of the huge potential that these stoves have to positively impact the health of the local people and ecosystem, and we look forward to trialing them with RIPA and Alianza Arkana’s Grow & Cook program. Stay posted!

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Posted by Fin Forster-Davies, Alianza Arkana Volunteer, 22nd October 2014

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