[Stoves] MUST CHARCOAL BE A CAUSE FOR CONCERN?

[Crispin Pemberton-Pigott]

Dear Rogerio

We discussed this a while back and I forwarded some example of the energy
balance.

Yes, the fact is there is nearly no difference between the amount of food
cooked with wood or that same wood turned into charcoal. The caveats are
that I depends on the wood stove, the charcoaling method and the charcoal
stove.

Those are three huge variables, but for 'medium quality' on all three
counts, the answers are about the same.  

The overall difference that one might be inclined to ponder is the amount of
energy that is used to being the fuel to the cook. In the case of charcoal,
say in Mozambique, the distance that one can profitably transport charcoal
is far greater than that for wood because it is so much more energy dense.
It is even better than coal because coal usually has a lot of ash in it.

So, when considering what to criticise, replace and promote, one has to look
at the three main variables, what one could do to change them, and what the
transport implications are. It is pretty tempting to think of charcoal
making vehicles using wood gas for locomotion, delivering charcoal to the
cities. They would start off heavily loaded and get lighter as they got
closer to town! 

I recall Cecil Cook and I having fun with this equation some time ago.

What is always good (as Richard Stanley recently point out) is to make sure
that all the chips and dust from the charcoal business end up in briquettes
of some form. Usually the review of charcoal is made by a hostile agent and
the 'waste' involved is emphasized, not the methods by which it can easily
be made very efficient, all things considered.

There is still a lot of this story to be told by someone with a talent for
integrating technologies and stove ideas.

Regards
Crispin


+++++++++++++++ 

>I found the following quote on a FAO publication
(http://www.fao.org/docrep/005/y4450e/y4450e10.htm), and I wonder if this is
a correct statement responding to the question :

"Must charcoal be a cause for concern?

The shift from fuelwood to charcoal, even if it lasts only a few decades,
could have major ecological consequences if it is not kept under control.
However, since charcoal stoves are more efficient than wood stoves, the
ratio of primary energy to usable energy is almost the same as with
fuelwood. Thus with adequate supervision, management and support, the shift
does not need to disrupt present levels of resource use."

What do you think?  Can at the end, with actual stoves and charcoaling
efficiencies, be the wood consumption the same?

Rogerio