[Stoves] ETHOS Discussion about decentalized stove efforts

[Dr.-Ing. Dieter Seifert]

Dear all,

My name is Dieter Seifert and I am active in the area of renewable 
energy (e.g. parabolic solar cookers), together with my family, forabout 
30 years.

Maybe some quantitative considerations in the debate on the question of 
decentralized cooking power supply are helpful. Using the combination of 
efficient stoves and the "thermos technology" (cooking with retained 
heat), only small amounts of fuel wood are consumed, so that a 
sustainable supply is possible. Refering to data from Table 2 in the 
article of R. Bailis "Wood in Household Energy Use" in the Encyclopedia 
of Energy, Vol. 6, Elsevier (2004) , p . 518 (for Nairobi as example for 
urban households):

a) consumption of firewood with open fire: 1626 to 3250 kg firewood per 
household per year at 10  to 20 percent efficiency;
b ) consumption of charcoal with improved or regular stove 531 to 1238 
kg charcoal per household per year at 15  to 35 percent efficiency .

If we assume that the charcoal is produced with the conventional 
conversion factor of 6 tons of wood per ton of charcoal, then this 
corresponds to a consumption of 3186 to 7428 kg of wood (mature trees!) 
per household per year. The consumption of wood or charcoal may be much 
higher in countries with higher forest cover still present.

If we consider a household that uses an improved stove with more than 30 
% efficiency and the thermos technology, then the consumption per 
household per year can be reduced to approx. 600 kg of wood (thin 
sticks, not trees). This can be achieved by a stove with grate and with 
shielding of the pot and, for example, 1 or 2 hay-baskets with a straw 
pillow under the pot and cotton pillows around the pot and on the lid of 
the pot - and enough hot pot contents. The firewood consumption is thus 
reduced to a small percentage (less than 10 % compared to charcoal-use).

The hay baskets are a typical appropriate technology and it is 
inconceivable that the wonderful opportunities of thermos-technology are 
still very limited, concerning to the avoidable damage to the health and 
prosperity of families and to the environment.

The supply of urban households with the thin sticks is an opportunity 
for income generation. The support of this change should be recognized 
as a public task. In contrast to the established charcoal supply for 
urban households these incomes are sustainable, as it is only a matter 
of time when the incomes from charcoal will cease (with growth rates of 
the urban population of over 3 percent, i.e. doubling of urban 
population every 20 years) as the sources dry up and the country is 
deforested.

The necessary measures can be accomplished in a decentralized manner; 
but the necessary information and practical advice could be disseminated 
through the global education system, as we know that for the acceptance 
of the required change, it is necessary to involve the parties affected, 
to recognize and realize the challenges and opportunities.


With kind regards,
Dieter


Dr.-Ing. Dieter Seifert
Neuoetting/Germany
bdiv.seifert at t-online.de

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