<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: Arial; font-size: 12pt; color: #000000'>Jan - 1. This is to hope you can add a little more data so we can
more accurately figure out a payback time for a charcoal-making (Pyrolyzing) stove in
Tanzania (with extensions presumably to other countries). For ease of
comparison, I will convert using 1617 Tsh to $1.<br>
<br>
2. Your two hour cook time costs $0.155 for 1 kg of Jatropha seeds,
$.62 for maybe 1.2 kg (or $.50/kg??- lower energy density) wood, and
more ?? for charcoal (guess at $.80?? for maybe 0.8kg of (higher energy
density) char valued at $1/kg ??). Asking you to correct these
guestimates based on your description below.<br>
<br>
3. Assuming you can get back from the first two about 25% char then
the return value for Jatropha is 0.25kg*$1/kg, so the cook made $0.10
per meal using Jatropha seeds. For wood, about 0.3kg *$1.00/kg - so
he/she saves about half of the $0.62. Much better buy to go with
Jatropha seeds (as you have been saying - but maybe not true in India -
but who still may see an ag value per the folowing and may have an equally good alternative waste ag fuel).<br>
<br>
4. Assuming there are two periods in the day for using the 1 kg of
jatropha seed, making $0.20 per day, then a one year pay back can occur
on a stove costing $73.00. (I think you are aiming lower)<br>
<br>
5. What the Biochar folk want is to not sell the char back, but to
place it in the stove-user's garden. Each year there would be in this
example about 1/2 kg per day of char or 180 kg in a year. At 10 tons
per hectare loading (same as 1 kg/sqm), this stove would cover180 sqm,
if used twice a day. So assume a 1/2 meter strip, we can get a linear
0.36 km. If garden producing at 2 tons per hectare sees a doubling to 4
tons per hectare, then the 180 sq meters gets an increase of 200 gm/sqm
(100 gm/linear meter) - or new added annual garden output of 36 kg
(onions, carrots, squash, etc). Nothing in Colorado is less than $2/kg -
so maybe the extra first year value (halving the $value for high value
Tanzanian market crops) is near $36. If the initial cost could be
taken from savings, then we are up to $110 per year in return (rounding
$113 down). If no more char is placed in the ground, and the stove
lasts 5 years, then the total stove income is $550. <br>
<br>
6. But the Biochar keeps coming and giving, so at the end of five
years of putting char in new ground, we are not deaing with a linear
.36 km, but 5 times that or 1.8 km of vegetable row, and the number of
row-years is up to 1+2+3+4+5 = 15 row-years (10 more than the previous
5) . If one row year gave a new annual garden income of $36. and the 5
year total income was $550, then the new total would be $550+10*36 =
$910.<br>
<br>
7. But, the Biochar is still working after 5 years, so, now using a
discount factor, maybe we can convince the potential stove buyer that
there is another $100 available should the land (now up to (a
postulated) loaded 900 sq m, [or 0.09 hectare - approaching a quarter of
an acre] be sold. In total over $1000 profit on a $73 investment on a
stove - within the first 5-years No environmental cost that I can see
and the fuel-seeds were bought - not picked (not very likely). It gets
better when you factor in inflation and devaluation of the Tsh. A
return on investment around a factor of 15.<br>
<br>
8. Should the investment in a char-using stove be preferred, the
5-year outgo in dollars for a "Thrifty" $5 jiko would be 5 yrs*365
days/yr*2 meals a day*$0.80/meal =8*365>$2600. The difference is
over $3400 on the $68 price difference - a factor greater than 20. It
doubles for those picking their own seeds.<br>
<br>
9. This is considerably low-balled in some cases, since Nat Mulcahy
of World Stoves says his stoves (with a 5-year guarantee) are seeing a
large use (factor of 3 or more??) for boiling water and other
income-generating activities. But 20 is a good round return number to
start with.<br>
<br>
10. Jan - Did I do the fudging somewhere near correctly? I am
assuming 18 MJ/kg for wood and about 30 MJ/kg for char, with Jatropha
seeds in between somewhere. Here's hoping you (& others) can sharpen
the computation a bit (for other combinations of charcoal-making vs
charcoal-using and a more healthy, less time-consuming kitchen to
boot. Health based $ statistics for lost work days should be figured in)<br>
<br>
Ron<br>
<br><br><hr id="zwchr"><b>From: </b>"Jan Bianchi" <janbianchi@comcast.net><br><b>To: </b>"Discussion of biomass cooking stoves" <stoves@lists.bioenergylists.org><br><b>Sent: </b>Friday, August 12, 2011 1:47:42 PM<br><b>Subject: </b>Re: [Stoves] Jatropha and its future<br><br>A.D<br><br>Sounds like you've got a good market for jatropha in India. In Tanzania<br>Africa, where much of what has been planted is going unharvested, it sells<br>for about $250 Tsh per kg which has a burn time of more than two hours,<br>whereas a bundle of wood with a two hour burns time costs $1,000 Tsh.<br>Charcoal costs even more<br><br>So its all about location.<br><br>Jan<br><br><br><br>-----Original Message-----<br>From: stoves-bounces@lists.bioenergylists.org<br>[mailto:stoves-bounces@lists.bioenergylists.org] On Behalf Of Anand Karve<br>Sent: Thursday, August 11, 2011 8:44 PM<br>To: Discussion of biomass cooking stoves<br>Subject: Re: [Stoves] Jatropha and its future<br><br>Dear Ron and stovers,<br>there is a good market for Jatropha seeds in India. Itinerant<br>merchants go from village to village and buy Jatropha seed from<br>anybody who wants to sell it. Since this commodity has a value, the<br>seed of Jatropha planted as hedges along the boundary of one's<br>property usually gets harvested by somebody else, The property owner<br>may harvest only the seed on the internal side of the hedge. Jatropha<br>was planted as a hedge plant long before there was any talk of<br>biodiesel. If one plucks a leaf of Jatropha, latex oozes out of the<br>wound. This latex foams like soap. In some rural households there are<br>a few Jatropha plants right next to the latrine. After defacation, the<br>user of the latrine plucks a couple of leaves, crushes them in his<br>hands and uses them to wash his hands. Nobody really bothered to find<br>out what was done with Jatropha oil. Most of the non-edible oils in<br>India, like Pongamia, Callophyllum, neem, etc. are bitter and brown in<br>colour. Jatropha oil is colourless and it does not have any strong<br>taste or smell. Even the fatty acid composition is similar to most of<br>our edible oils. Therefore I am quite sure that it is used, even<br>today, as an adulterant in edible oil. At its present price, nobody<br>would use whole Jatropha seed as stove fuel in India.<br>Yours<br>A.D.Karve<br>On Thu, Aug 11, 2011 at 7:33 AM, <rongretlarson@comcast.net> wrote:<br>> Jan and list:<br>><br>> Thanks for the detailed responses. I hope you can continue to supply<br>good<br>> photos like those we have seen. Very helpful in figuring out how to make<br>> pyrolysis stoves move faster. I think the central secondary air post has<br>a<br>> lot of promise. I believe a combination pot and stove combination could<br>> give high efficiency with where you are heading, since you already have a<br>> convective shield geometry. As said earlier, I think a control over<br>> primary air is important and will prove valuable in more than the shutdown<br>> operation<br>> The use of the full jatropha seed seems to be a good solution where<br>rural<br>> folk need propety boundaries. In reading about jatropha, I see there are<br>> big gains to be made in seed production through proper pruning (same as<br>for<br>> almonds) - so your stove system could have a bigger supply than now being<br>> planned for and can maybe get to more urban folk as well.<br>><br>> Ron<br><br>_______________________________________________<br>Stoves mailing list<br><br>to Send a Message to the list, use the email address<br>stoves@lists.bioenergylists.org<br><br>to UNSUBSCRIBE or Change your List Settings use the web page<br>http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists<br>.org<br><br>for more Biomass Cooking Stoves, News and Information see our web site:<br>http://www.bioenergylists.org/<br><br><br><br><br>_______________________________________________<br>Stoves mailing list<br><br>to Send a Message to the list, use the email address<br>stoves@lists.bioenergylists.org<br><br>to UNSUBSCRIBE or Change your List Settings use the web page<br>http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org<br><br>for more Biomass Cooking Stoves, News and Information see our web site:<br>http://www.bioenergylists.org/<br><br></div></body></html>