[Stoves] Comparing liquid fuel stoves

[Tom Miles]

Paul,

Thanks or the summary. Fuel and choices are pretty site specific and vary
over time. Project Gaia has had some very useful responses to their testing
and surveys in Ethiopia, Uganda and Brazil.
http://www.bioenergylists.org/en/taxonomy/term/159

Some areas may be more appropriate for alcohol stoves than for oil. Both
must compete with paraffin (kerosene) or LPG. It helps to understand the
relatives differences in cost and performance of liquid fuels since we
devote much of our discussion to solid fuels. 

Regards,

Tom 
  


------------
Paul Anderson sends the following PARTIAL data on the Lily alcohol 
stove, and he
will try to get better data in the future:

Power range:  The stove can have 1 or 2 or 3 Lily burners under one 
normal-size
pot.  One burner running "low" is probably 0.8 kW.  Three burners running
"high" are probably close to 5 kW.

Usage:  [data based on Project Gaia results in Ethiopia and Brazil].  Each
family normally needs 1 to 1.2 liters of alcohol per day, being about 360 to
440 liters per year.

Fuel:  ethanol or methanol.  Does NOT need to be the "vehicle-quality" 
alcohol. Alcohol with zero to 20% water will operate, but expect a 
proportionate increase
in the volume of fuel needed.

Efficiency:  There is combustion efficiency and heat-capture efficiency.
For
combustion efficiency, alcohol is about as high as you can get.  For heat
capture efficiency, the Lily stoves can increase or decrease that efficiency
with the addition of pot skirts, so stove cost can become a factor in
efficiency.  Therefore, I consider efficiency data to be interesting but of
limited (or perhaps misunderstood or misrepresented) value for comparing
stoves.

Emissions:  About as good as you can get.  Aprovecho and Harry Stokes 
and others
have some data.  Note:  The self-pressurized alcohol stoves (including 
the Lily
burners) probably have slightly better (lower) emissions than do the
non-pressurized burners like the CleanCook that have a much larger exposed
surface for vaporizing the alcohol.

Stove costs and fuel costs should also be added to the list for comparisons.

Stove costs:  The Lily burners should be produced (using new materials, not
recycled tin cans) for under US$2 per burner.  Nice to have 3 or 4 burners,
so
call it US$6 to $8.  And a nice basic stove structure should also be made
for
less than $10, but really attractive stoves structures could be much higher.

Fuel costs:  In Ethiopia, the cost for purchase is about 25 cents US$ 
per liter
of ethanol.  Micro-distilleries are possible (less capital and use local
labor), but large distilleries have economies of scale to be considered.

Lily Stove:
http://www.vrac.iastate.edu/ethos/files/ethos2007/Sat_AM/Session_1/Anderson%
20alcohol%20stoves%202007-01-26.ppt

By the way, alcohol stoves (specifically the Lily burners) are only a side
interest of mine.  I have found no finacial support for further 
development. Perhaps Lily stoves will be made and tested in Ethiopia.
**********

I agree with Tom's comment:
> It would be useful to put the data in the same terms.

But even in the same terms, it is like comparing apples and oranges, or 
should I
say like comparing oil-seeds and sugarcane.

Even with correct data, we need to do some thinking about comparisons 
of liquid
fuels and their various stoves.

Paul