[Stoves] Calculating cooking costs and char costs ----Re: [biochar] Where to discuss STOVES AND CARBON offsets and drawdown

Sun Sep 17 16:48:29 CDT 2017

Kevin:

Thank you for the clarification. Indeed, coming to think of it, a
"mealtime" as a "cooking session" is a better unit than "per day". For
energy balance purposes, one can just guess an average of daily
"mealtime-equivalent".

Yes, too, that "energy per meal" must be used with caution. If I am not
mistaken, Kirk Smith cooked up some estimates of "co-benefits" - health and
climate - of LPG which at their origin must have some quantification of
energy used (for boiling water, if nothing else). Many such calculations
have been made on the basis of "useful energy" per meal, and I am culpable
as well.

I don't have anything else to offer, just that cost of wood varies by
quality and context, as does valuation of char. It is one thing to make
some specific computation for a million meals-equivalent a year (500 stoves
for 1,000 mealtimes a year, say) and quite another for 500,000 stoves. No
resource is infinite; land, water and labor have opportunity costs.

Alternatively, suppose in a "small" geography, biomass used is all "waste",
even with a negative price (the cost to remove or avoidance of rotting and
subsequent hazards depending on the context). Aggregating such small
geographies and satisfying the auditors general of voluntary carbon markets
can also be very costly.

Charmaking is probably best pursued as an industrial enterprise, as indeed
it is in rich countries. Unless the opportunity cost of biomass is
practically zero - say, US$ 0.02 per kg for low-quality waste. What the
supplier of wood doesn't earn will be eaten up by the overheads of carbon
market. There is a royalty of expert computers out there.

Nikhil

Nikhil Desai
+91 909 995 2080 <+91%2090999%2052080>
Skype: nikhildesai888

On Sep 15, 2017, at 6:35 PM, <kchisholm at seaside.ns.ca> wrote:

Hi Nikhil

I used the term “mealtime” more in the context of a “cooking session”.
Clearly, a number of meals would be required at “mealtime.”

Knowing the number of meals prepared at the “mealtime”, one can then
determine the wood consumption per meal, and ultimately, the “energy per
meal.”

Note also that the “energy per meal” must be used with caution, in that it
will vary with the nature of the meal. For example, a meal of rice and fish
could require a different cooking time than when simmering a stew or
boiling eggs.

Note also that the purpose of this particular Spread Sheet was to give an
approximate value to char produced by TLUD’s. Would you have any further
comments or suggestions in how to improve it in this regard?

Thanks, and Best wishes,

Kevin

*From:* Nikhil Desai [mailto:pienergy2008 at gmail.com <pienergy2008 at gmail.com>]

*Sent:* Friday, September 15, 2017 6:09 PM
*To:* Discussion of biomass cooking stoves <stoves at lists.bioenergylists.org>
*Cc:* kchisholm at seaside.ns.ca; biochar <biochar at yahoogroups.com>; Hugh
McLaughlin <hsmclaughlin at verizon.net>
*Subject:* Re: [Stoves] Calculating cooking costs and char costs ----Re:
[biochar] Where to discuss STOVES AND CARBON offsets and drawdown

Paul:

Two comments:

1. If "mealtime" refers to a day (and 3 cooked meals per day), 1 kg wood
per day seems to be on the low side, unless it is per capita. I remember
that a "rule of thumb" (or "expert estimate") back when people prepared
national energy balances, was "1-2 kg wood *per capita* per day". Of
course, the gross input per family depends on many factors including
efficiency, types of cooking tasks, age/sex composition, ambient
temperature and wind patterns, and cook's whims; however, if the per family
net energy per mealtime is 3.7 kWht or 5,750 Btu, I suspect the family may
be too poor to afford enough food from scratch - relying on more fresh
vegetables or uncooked materials or on partially prepared purchased food.

This single number -- how much useful (net) energy per family per year is
"required" on average in a given context - would seem to be very useful,
with some assumed efficiencies,  for computations of emissions and
deforestation or loads carried on heads or backs. But I have seen very few
such attempts. Any thoughts? I will dig up some GACC studies.

2. The way the spreadsheet is set up, the financial cost of fuelwood is the
most critical assumed parameter for the breakeven carbon credit value
(CCV). Only at $0.02/kg cost of high-quality wood does the CCV come close
to today's price in the EU ETS. Since the supply curves for both wood and
labor are likely to at least somewhat upward sloping, the question becomes,
what is the potential - in global terms - for biochar to compete with other
CDR options?

It would seem that biochar for CDR and charmaking for local sales (as fuel)
are two entirely separate markets and will probably remain that way for a
long while.

Does anybody have a good number for useful cooking energy per household per
year?

Nikhil

On Wed, Sep 13, 2017 at 10:53 PM, Paul Anderson <psanders at ilstu.edu> wrote:

Kevin,

Thanks for the spreadsheet.  This is an interesting situation where
calculated numbers are not matching with some human activities about the
value of charcoal.

This discussion is only with the Biochar group, so I am adding the Stoves
Listserv and attaching the spreadsheet.

Notes;

The use of BTU/LB in columns H and I should be in the green (calculated)
values and the corresponding metric units (which you provide) should be the
yellow variables that can be entered.  Please.

I notice that changes in the Value of unburned char/kg  (C23 ) is
essentially linked to the cost of fuel wood  (C5) , and therefore virtually
dictate the conclusion of carbon credit pricing needed (C28 ).   So, the
price stays quite high.

****************
A.  Consider the case of the cook who has no real use for the char, which
means that the cost of fuel  is 100% allocated to the cooking, and the
resultant char has zero  value.  To that cook there is no trade-off about
char being used for cooking other meals.    Selling the char is "pure
profit", whether it is a calculated value of $0.16/kg (as in C26) or merely
$0.12/kg as in Deganga, India, or only $0.08/kg which is still better than
nothing.

B.  Current "traditional" cooking with charcoal that is produced by
generally inefficient "traditional" char-making methods would have a char
yield  (C6) of between 10% (burning too much to ash) and 25% (leaving
volatiles in the char, or even some incomplete pyrolysis/torrification).

C.  But for those people who produce traditional char, the "cost of fuel
wood" (C5) could be as low as zero (illegal cutting or destructive cutting)
or some notional value of the time spent to make the charcoal.

Others need to comment also.

Paul

Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD

Email:  psanders at ilstu.edu

Skype:   paultlud    Phone: +1-309-452-7072 <(309)%20452-7072>

Website:  www.drtlud.com

Doc  /  Dr TLUD  /  Prof. Pa

*From:* biochar at yahoogroups.com [mailto:biochar at yahoogroups.com
<biochar at yahoogroups.com>]
*Sent:* Monday, September 11, 2017 4:02 PM
*To:* Hugh McLaughlin <hsmclaughlin at verizon.net> <hsmclaughlin at verizon.net>;
biochar at yahoogroups.com
*Subject:* Re: [biochar] Where to discuss STOVES AND CARBON offsets and
drawdown

Hugh and Kevin,

First to Hugh:  Why do you write

$0.10/kg is a more reasonable assumption.

when that is what Kevin actually said.

Then to Kevin:  Actually, it the char yield is 20% per kg of fuel (closer
to actual than is 25% or 30%), then the number becomes $US 250 per tonne of
char = $US250/3.42 = $US 73.10 per tonne of CO2 equivalent.

To all:  As reported in the Deganga Case Study (page 4, 3rd paragraph), in
that case study the  people *were actually paying US$0.075 per kg of
firewood.*   And they burn 3 to 4 kg per day (which is less than half of
baseline fuel consumption).  Note:  4 kg of firewood at 20% char yield
would be about 0.8 kg of char per day (matches the measured quantities of
char purchased from the households).

And they were receiving payment of $0.12 per kg of char via the "Earn while
you cook" arrangements (page 4, second paragraph from the bottom of the
page), which would be $0.04 per 0.3 kg (just citing Kevin's initial number
for some comparison) or $0.024 per 0.2 kg (the approximate actual char
production per day of cooking.).

Can we use some of these above numbers and send a revised statement,
please?

And if the point is still

it is more advantageous for the Cook to burn it [the char] for another meal.

then why are the people  so delighted with the charcoal buyback?   ( ??
cultural reasons??? such as not having a tradition of cooking with charcoal
at the household level (true) ...   or their perception of the value of a
few cents is greater than their perception of the expense of the cooking
task?  ... or some other reason(s) ???

All are welcome to comment, please.

Paul

Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD

Email:  psanders at ilstu.edu

Skype:   paultlud    Phone: +1-309-452-7072 <(309)%20452-7072>

Website:  www.drtlud.com

On 9/11/2017 1:22 PM, Hugh McLaughlin wrote:

ERRATA: $10/tonne is $0.01/kg.

If there is any transportation, $100/tonne or the basis used for the
calculation: $0.10/kg is a more reasonable assumption.

Hugh McLaughlin, PhD, PE

CTO - NextChar.com

On Monday, September 11, 2017 2:03 PM, "kchisholm at seaside.ns.ca [biochar]"
<kchisholm at seaside.ns.ca[biochar]> <biochar at yahoogroups.com>
<biochar at yahoogroups.com> wrote:

Hi Paul

Assume that such fuelwood costs $US10 per tonne, or $US.10 per kg.

Assume that 1 kg of such wood is “burned” in a TLUD, to cook a meal, and
that there is .25 kg char yield.

Assume also that the char could be used to cook a second meal.

The cost of fuel per meal is thus $US.10, if the char is not used for
cooking, OR, it is $US.05 if the char is subsequently used to cook a second
meal.

Thus, if somebody gave the Cook $US.05 for the .3 kg of char, the Cook
could be “revenue neutral”.

Thus, the cost of “Carbon Credits” that reaches the actual Cook should be a
minimum of $US.05/.3 kg char = $US.167 per kg char, or $US167 per tonne
char = $US167/3.42 = approximately $US48.80 per tonne of CO2 equivalent.

CONCLUSION: With the costing and performance assumptions shown above,
unless the Cook gets more than the equivalent of $US48.80 per tonne CO2
carbon credits, it is not advantageous for the Cook to “sell” the char… it
is more advantageous for the Cook to burn it for another meal.

Does this make sense to you?

Best wishes,

Kevin

*From:* biochar at yahoogroups.com [mailto:biochar at yahoogroups.com
<biochar at yahoogroups.com>]
*Sent:* Monday, September 11, 2017 11:53 AM
*To:* biochar at yahoogroups.com; Doc Anderson <psanders at ilstu.edu>
<psanders at ilstu.edu>
*Subject:* Re: [biochar] Where to discuss STOVES AND CARBON offsets and
drawdown

Dear Shengar,

Thank you for the input.

World figures are that about 3 billion persons have meals prepared on solid
fuel (mostly biomass).   Family size (especially HOUSEHOLD size, referring
to the number of people who eat together) should be 5 or 6, which would
put the number of households between 600 million and 500 million.   Those
are the numbers that I prefer to use.

I agree with nearly a kilo of char produced per day per TLUD stove
(confirmed in Deganga, India, study).  365 days would yield about a third
of on ton of char per household.  3 household become a ton/yr.    30,000 HH
would be 10,000 tons.  300,000,000 HH (about half of the needed cookstoves)
would be 100,000,000 tons.

So it would take 10 years to reach one GIGA ton, which is 1,000,000,000
tons.   (Please check my math.)

In the Drawdown project, the time period is 2020 to2050, which is 3 decade,
or "potentially" 3 gigatons of char sequestration.

3 GT is only 1/5th of the GT calculated for ALL cookstoves, and over 3
times more that what was calcualted for ALL biochar by 2050.  Clearly there
is more to the drawdown calculations than the simple numbers above.

Paul

Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD

Email:  psanders at ilstu.edu

Skype:   paultlud    Phone: +1-309-452-7072 <(309)%20452-7072>

Website:  www.drtlud.com

On 9/11/2017 1:27 AM, shengar shengar at aol.com [biochar] wrote:

The ballpark numbers I think Albert Bates has crunched but I play with
these numbers:

About 1 billion households cook with biomass, so if all had TLUDs,
producing about a kilo per day of biochar that would be some one million
tons per day, 365 million tons per year, a gigaton of CO2 every 3 years.
(accounting for other greenhouse gas reductions when biochar is put in soil)
And increased rates of soil carbon sequestration
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