Dear Paul
I append my original message, on this thread, below. What leads you to believe
that I only equate fuel with wood and trees?
Equally, why do you feel that Crispin only equates fuel only with wood and
trees?
In my clip from an excel spreadsheet, I clearly show both Ag. Waste and Stick
Fuel stoves in my example, with no prejudice or advantage extended to either.
Additionally, I show both "char producing" and "full combustion" stoves, with
no prejudice or advantage extended to either. I leave it entirely to the
Customer to decide which stove system is best for him.
How is that being unscientific?
Kevin
----- Original Message -----
From: Paul Anderson
To: Discussion of biomass cooking stoves
Sent: Wednesday, April 24, 2013 3:13 PM
Subject: Re: [Stoves] FW: REQUEST for complete sets of raw data of cookstove
tests.
Dear Crispin and Kevin,
You are happy to talk about Fuel efficiency, and use ENERGY numbers. And
then immediately discuss forests being destroyed.
Please get past the equating of fuel with wood and trees. Beating on that
drum constantly is unscientific.
Paul
Paul S. Anderson, PhD aka "Dr TLUD"
Email: [email protected] Skype: paultlud Phone: +1-309-452-7072
Website: www.drtlud.comOn 4/24/2013 9:49 AM, Crispin Pemberton-Pigott wrote:
Dear Kevin
You analysis is correct. When rating the performance of a stove from a fuel
use perspective, the chart is correct:
Two stoves are being compared for "Efficiency".
Given facts from Tests:
STOVE A
STOVE B
STOVE C
STOVE D
Nature of Fuel
Ag. Waste
Ag.Waste
Stickwood
Stickwood
Fuel Energy Supplied, MJ
10
15
10
15
Energy to Cooking Pot, MJ
5
5
5
5
Energy in Char, MJ
0
5
0
5
Stove Efficiency, %
50.00%
33.33%
50.00%
33.33%
If someone is interested in the char, it can be reported. What Ron is
proposing, to add that heat energy available in the char back into the mix, is
akin to considering the energy efficiency to be the fuel efficiency which is
precisely what created for us a problem in the first place.
The energy value of the char came from somewhere. Consider a stove that
takes 2 tons of forest per year. If it produces ΒΌ of a ton of forest's worth of
energy in the form of char, fine. Say so. But saying so does not reduce the two
tons of forest it takes. If you have (as you pointed out) a second stove that
can utilise the charcoal, then that can be viewed as a 'system' by all and
sundry, but is still does not change the fact that Stove 1 takes two tons of
forest each year which is what the reported fuel consumption should be. No
smoke and mirrors.
Burying the char as a soil amendment instead of burning it merely takes
us back to the two tons of forest per year draw-down and returns it to the
environment in an (apparently) inert, solid form.
What has been happening that is wrong, in my view, is that stoves that
take off 3 tons of forest per year have been getting credit for taking only one
ton and proclaimed to be 'better' and 'more fuel efficient' than a two-ton
stove. Plainly this is not the case and the test method has to report the fuel
consumption correctly. It is a problem that the UNFCCC methodology does not
handle this well because it is being used for CDM trades.
Regards
Crispin
----- Original Message -----
From: Kevin
To: Discussion of biomass cooking stoves
Cc: jetter jim
Sent: Tuesday, April 23, 2013 6:49 PM
Subject: Re: [Stoves] FW: REQUEST for complete sets of raw data of
cookstovetests.
Dear Paul
(comments below...)
----- Original Message -----
From: Paul Anderson
To: Discussion of biomass cooking stoves
Cc: jetter jim
Sent: Tuesday, April 23, 2013 4:11 PM
Subject: Re: [Stoves] FW: REQUEST for complete sets of raw data of
cookstove tests.
Ron, Crispin, Jim and all,
One stumbling point is the difference between the words Fuel and
Energy. We cook with fuels. We cook with energy. But a piece (1 kg) of
wood (fuel) can deliver 16 MJ of energy if burned to ash or it can deliver
(example) 11 MJ of energy PLUS charcoal that represents 5 MJ of energy.
The piece of wood is totally changed in both cases. But in the second
case, part of that wood has been transformed into charcoal, which is certainly
not wood. Wood consumed is 1 kg. Energy consumed is 11 MJ (with charcoal
left over). Two very different results to be reported.
And then there is the case of one kg of agricultural "refuse" that is
16 MJ if consumed totally, or 11 MJ plus charcoal if pyrolyzed, and in NEITHER
case was there any consumption of wood. Where deforestation is an issue,
stoves that can use (easily use) agricultural refuse need to be distinguished
from the wood burners.
# To view the issue differently...
Two stoves are being compared for "Efficiency".
Given facts from Tests:
STOVE A STOVE B STOVE C STOVE D
Nature of Fuel Ag. Waste Ag.Waste Stickwood Stickwood
Fuel Energy Supplied, MJ 10 15 10 15
Energy to Cooking Pot, MJ 5 5 5 5
Energy in Char, MJ 0 5 0 5
Stove Efficiency, % 50.00% 33.33% 50.00% 33.33%
# So, we see that for the same cooking task, Stove A and stove C have
the best efficiency, both at 50%
while Stoves B and D also have the same efficiency, both at 33.33%
# Now it is up to the Customer:
IF HE WANTS CHAR, he chooses Stove B if he has Ag Waste for fuel, or
stove D, if he has stickwood fuel
IF HE DOES NOT WANT CHAR, he chooses Stove A if he has Ag Waste for
fuel, or stove C, if he has stickwood fuel.
# Thats all the Customer needs to know, in order to make the best
choice of stove for his circumstances.
Even when the stove testing is conducted with wood as the standard
fuel, the test RESULTS need to clearly reveal that wood did NOT need to be
burned.
# This is an efficiency test. This is not a test of the merits of using
Ag. Waste or Stickwood. The test tests teh stove with whatever fuel is supplied.
In the movies, "No animals were harmed in the production of this film."
For SOME cookstoves, "No wood was burned in the cooking of these meals
(or the conducting of these tests)."
# That is an issue above and beyond Stove Efficiency Testing.
What happens to the charcoal (whether burned or as biochar or otherwise
lost) should not be the issue.
# The "Efficiency Test" is a measure of "efficiency of utilization of
fuel by the device being tested." Regardless of the value of the char
production, the simple fact is that the char represents non-utilization of the
fuel supplied to the device being tested. The fact that the char could be used
in another stove, or could be used as Biochar for soil Application is another
issue entirely. If we take credit for the fact that the char could be used
elsewhere in another system, we could really confuse the issue if we claim such
things as :
" 20% of the supplied energy was lost through the sidewalls of the
stove but it heated the kitchen beneficially, so I think the Stove Efficiency
should be increased by 20%
or
" I am using the stove to heat a small enclosed greenhouse, and I am
venting the stack gases inside to use the CO2 by the plants. Since the fuel
contained 50% carbon, and it was burned to completion, I claim 100% 'Efficiency
of utilization of the fuel."
# External, or "subsequent usage benefits" are issues outside the scope
of "efficiency of use of fuel by the device being tested.
Best wishes,
Kevin_______________________________________________
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