We built the stove and it worked well, consumed less wood etcetera. But we could never get Swedi’s wife to care. I talked to her about it, after all, she was the one who brought cooking wood in from the forest, but for her learning how to use a new technology was more of a challenge than bringing in more wood and doing it the old way. I know that with more effort on our part we could have introduced the stoves more widely and maybe caused some forest conservation/eased the burden of the local female population. But I couldn’t because we had a medical program to take care of.

Anyway, what Aprovecho did so well is design something that is not DIY, but is build-able in rural settings from local materials and very usable. It is in fact a wood-gasification stove, in that it burns not just the wood but also the off gasses and smoke. This is how it achieves the 20x efficiency boost over an open fire. They actually developed the idea when working at a Guatamalan Refugee camp (sorry if my facts are off, I’m writing from memory and not wiki) and managed to figure something out that they could jerry rig out of available materials (that time it was metal cylinders and not ceramics but it worked in the same way). Refugee camps exact a brutal tool on surrounding ecosystems and people quickly run out of resources like cooking wood. This little do hickey made all the difference in the world, and I hope innovation like this continues to flourish and spread.

For a great back yard fire, Try doing what we do in New Hampshire.
1 Square off the ends of a hollow log, about 5 ft tall , 18″ diameter or better. Set it on 3-4 cinderblocks so it is elevated above the ground. use 3 or so metal fence posts to prop it up sturdy.

2. Light a small fire underneath the hollow log.

The Hollow log will act as a chimney directing the smoke out the top. Soon the interior of the “chimney” will ignite and the draft from being elevated will produce a vaccum with air rushing up. That super heats the gasses and what you get is a roman candle effect, like a tall candle burning out the top. Here’s an example, but none of a Yankee version. You gotta have it at least 5 foot tall for real fun http://edcommunity.apple.com/gallery/student/item.php?itemID=1430

I wonder how well this design works with a few charcoal briquettes as the fuel source. I don’t exactly have lots of sticks lying around my back yard.

When I was a child, my parents told me
“Don’t go near the cellar door
you can play anywhere else you like
but don’t go near the cellar door”

One day, when they were gone
I went to the cellar door
and I opened it

and I saw things

things I’d never seen before

trees, and grass, and the sky…

At MakerFaire, there was the guy running a diesel engine off gassification of woodchips, and piping his carbon exhaust into an algae tank (realistically it would have taken a huge number of algae tanks to deal with the carbon exhaust, but it was proof of concept.)

There is so much to be gained in efficiency in energy generation and usage.

BoingBoing should do something on the Sterling Allan’s FreeEnergyNews.com / PESWiki.

http://www.kk.org/cooltools/archives/000012.php

One of the advantages of the rocket stove, that I didn’t see mentioned, is that it produces less smoke. Indoor cooking smoke is a leading cause of blindness in situations where an open fire is used.

Could a coal burning variant of this be designed?

The Chinese use cake-shaped lumps of processed coal in their home stoves. Imagine if they got coal sticks instead, designed to be shoved into a variant of these. Hotter, cleaner.

http://www.butser.org.uk/iafimg5_hcc.html

http://www.timelyconstruction.com/MasonryHeaters/MarkTwain.htm