[Stoves] News: National Geographic on promotion of gas stoves over improved woodstoves - in Guatemala

Wed Sep 6 05:19:03 CDT 2017

Nikhil, Crispin

I think the remark about “Solid fuel stoves that cook the fuel are much cleaner, generally, than those which don't.” has to do with the removal of the volatile fraction of the fuel, which, for instance in bottom-lit fires, is driven off by heat as “smoke”.  I recall our experiments with a 24MJ/kg coal burned bottom-lit, and the “smoke” collected on a small electrostatic precipitator we built. The ESP soon clogged! The material recovered from it was 33MJ/kg. Pyrolysing the coal at ~400 deg C until the volatiles were reduced to ~8% gave a 21MJ/kg fuel that emitted <5% of the smoke that came off the unpyrolysed coal under the same conditions.

Preheating the fuel, as happens in Crispin’s “cross-draft” stove, must help to release the volatiles early.  Well mixed with primary air, they then burn cleanly, and there is no smoke.

It’s only a working hypothesis; it would be interesting to sample the atmosphere in the fuel bed at the bottom of the preheating zone.

Philip

From: Stoves [mailto:stoves-bounces at lists.bioenergylists.org] On Behalf Of Nikhil Desai
Sent: Wednesday, September 6, 2017 4:36 AM
To: Crispin Pemberton-Pigott
Cc: Discussion of biomass cooking stoves
Subject: Re: [Stoves] News: National Geographic on promotion of gas stoves over improved woodstoves - in Guatemala

Crispin: 

I am humble, not a humbler. Of course I won't have heard of "Guidance Unto the Ignorant". I learnt some 25+ years ago, "You don't know more, you just know different things." (From a 4-year old. I celebrate her as my teacher.) 

Of course "pride of ownership" matters and factors into "price of ownership" users are willing to pay. That was the point of my "Modern Cooking" piece five years ago - moving away from purely "scientific" metrics and placing the cook in the center. 

I don't know how much coal is used in cookstoves; in India, limited to one or two states, more in rural China. I don't know about Indonesia, Colombia, Korea, Mongolia any longer. But I agree there is more potential in coal than general biomass (dung, straw, wood waste) simply because coals are regionally specific and can be made consistent quality by price premia for quality. Same can be applied to wood. All depends on how much fuel is self-generated (farm waste, dung) and collected.

All the "cookstoves and health" literature has failed to collect any data on stove type (the song goes "three stone fire or other traditional stoves"), fuel collection (scavanging or self-produced), dwelling type or size/quality of ventilation. If we bothered to define the context, we would have a better definition of the problems than theorizing in air-conditioned hotel rooms. 

I am not yet ready to endorse your view that "Solid fuel stoves that cook the fuel are much cleaner, generally, than those which don't." Because the quality and relative cost of fuels and stoves, and user preferences, matter. 

After all, cookstoves are for cooking meals, not merely generating heat. The heat that matters comes from spices and conversations. 

Nikhil

------------------------------------------------------------------------
Nikhil Desai

(US +1) 202 568 5831
Skype: nikhildesai888

On Tue, Sep 5, 2017 at 9:35 PM, Crispin Pemberton-Pigott <crispinpigott at outlook.com> wrote:

Dear Nikhil

As paid up members of Humblers Anonymous we should carry on offering what we can to whoever will accept it. Have you heard of the book from the 1800's "Guidance Unto The ‎Ignorant"? That guy should join our club. 

Regarding 'cool inventions': inventors want their creations to be considered as cool as they think they are. Customers often have a different concept of what is cool. 

In some markets 'pride of ownership' is about what others think is cool. It rates highly, number 3 or 4, in ranked purchasing decision contributors. 

For solid fuels and generating some sort of broad revolution, I hold far more hope for coal burners than wood because in a large fraction of places where coal dominates domestic energy, there is no option, or the option is limited and in the process of being actively conserved. It is far easier to burn coal cleanly than indeterminate wood. Animal dung is quite predictable but requires some basic processing in many cases. 

For biomass, processed wood and slash holds promise but the 'exciting' developments are (largely) in the grip of the char-makers with their own agenda to which the users should bend their lives. How often does that work?

If I advised the TLUD promoters I would suggest getting widespread adoption of the devices before trying to hornswaggle funding mechanisms for char buy-back ideas. If gasifiers generate twice the heat of charmakers from a kg of fuel‎, that is serious competition against the alternative. 

Solid fuel stoves that cook the fuel are much cleaner, generally, than those which don't. That's a fundamentally different approach and qualifies in my book as a shift as great as introducing kerosene. 

Regards 

Crispin 

Crispin: 

In all humility, may I suggest that your answer "Ignorance about how to invent cool stuff and get it adopted" comes across as a bit arrogant? 

Under conventional stereotype, where women are the principal home workers and hold exclusive responsibilities and powers over cooking and feeding (if not on purchase of food ingredients), I submit that cooking is about (a) women's time and energy allocation; and (b) the overall human environment, in and around the homes. 

There is perhaps not a single "cool" invention in solid fuel cookstoves does not seem to hold much promise for the Third World masses the way it happened with, say, Primus or Nutan stoves using kerosene some 60-80 years ago, or LPG/electric stoves and other thermal appliances over the last 50 years to this date. (There are fancy wood cookstoves in the Western markets as well). 

Then again, who knows, wood or pellet stoves with electric assist may change a lot. 

I do agree there is a wide chasm between the users and the inventors, and the overall context of fresh and waste biomass with considerable variation in economic geography, that may be said to limit success with solid fuel stoves in the past. 

Remember, the current fraction of humanity, the Bottom Half, is more variegated structurally from the upper half than was the case 50 or 100 years ago. And the bottom 20% if much farther apart in assets and income from the top 20% than ever, at least in the last 100 years. 

Population and human capital (health, education/skill-base, employment, security) dynamics are far more complicated than the simple mindsets of the 1960s to 1990s suggest (and which is what lies within many of us). 

Thank you so much for the pithy "Hence, the current mess." 

As GACC slides into the last three years of its plan, it's worth revisiting "the mess". Reformed thinking and institutional apparatus are necessary.  

Nikhil  

On Mon, Sep 4, 2017 at 11:59 AM, Crispin Pemberton-Pigott <crispinpigott at outlook.com> wrote:

Dear Gordon

- What are people trying to do?

Invent cool stuff and get it adopted to help save the world.

- What problems are getting in the way of your success?

Ignorance about how to invent cool stuff and get it adopted.

- What collaborations are possible?

The best one would be for the ‘stovers’ to approach social scientists to find out in much clearer detail why people behave the way they do when they use domestic energy and apply it in their lives.

There is usually a gulf between the wanna-be designers and the potential users, as large as the gap between marketing people and the self-same designers.

A three-way collaboration between marketing, design/engineering and behavioural scientists would produce products that would naturally attract funding. 

At the moment people seek funding first, technical solutions second, marketing expertise third, and a deep understanding of the users last.

Hence, the current mess.

Regards

Crispin 

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