[Stoves] High mass space heating options Re: Rocket Stove for the PLACE

[Crispin Pemberton-Pigott]

Dear Roger

 

>In this thinking I bring up the "Russian fireplace", The oldest and most
widely used High Mass heater I have known in my 26 years. They are typically
loaded up with 80 lbs of fuel and burned off one or two times per day.
That's up to 160 pounds every 24 hours, and no char is left. I believe that
the common EPA certified wood stove can provide just as much "useable" heat
to ones home with a lot less fuel, and no char is left. 
>        So, I am asking out loud.......are we better off selecting the heat
source that gets more for our waning resources, and maybe asking if there is
another medium for giving a home to these microbial critters other than just
the "char".

 

As I was pointing out at length, having an efficient heater (when it is
running) is quite different from having a high efficiency all the time.
Fires have a habit of going out and at time, very different physics come
into play.

 

You have probably heard that most fireplaces give almost no net benefit to
the house. This is certainly true of large old ones with a large chimney.
They pull so much cold air into the house and toss hot air up the chimney
that there is no net benefit. You are only warm if you sit beside the fire
which is exactly what people used to do. They had burning faces and frozen
butts.

 

This issue is not nearly resolved yet. There are ways to run an
EPA-certified stove that wastes huge amounts of heat so one has to tie the
claims of fuel saving to overall thermal efficiency. It has to be operated
correctly. Rare is the stove that properly operates itself.

 

There are very few people who toss left over char into the next fire. So
burning the fuel you have collected/paid for is one way to increase
efficiency. The drive to create char has a couple of roots. One was an
inability to make clean burning stoves. It was found that simple
batch-loaded TLUD stoves that were so choked for primary air that they made
charcoal, were surprisingly clean. That is because, it was believed at the
time, they were not burning the carbon, or most of it. Well, that is
interesting, but it wastes a lot of fuel that should have been burned. The
obvious risk is that it the stove is not thermally much more efficient,
people will go out and cut additional biomass to feed the stove that does
not burn all the fuel.

 

Enter the bio-char enthusiasts. They want to put char into the garden to
help with production of food. There are many claims and many disappointments
all over the world. There are successes and they tend to be smaller in
number than the claims and the failures. That is OK, research will fix up
the knowledge base and common sense will prevail. Don't fret.

 

It is a very big question as to whether or not one can make meaningful
amount of char with a stove. Meaningful means having a return on crops that
more than compensates for the collection (possibly) of additional fuel and
the effort to move that fuel to the kitchen and the char back again. So far
I have not seen a single case where this is going to be economically viable
on its own.

 

Enter the Climate people. They want to burn (sequester) carbon in the ground
on the understanding that if it is left there it will a) not re-emerge for a
very long time, b) will take carbon out of the air (biomass) and put it in
the ground, c) produce sufficient quantities of carbon offsets that they may
be sold to a willing buyer (probably in Europe) and d) bring some arguable
agricultural benefit - which is still being argued.

 

Notice that the plot has not become very complicated. The original problem
was not that we should build pyrolysers for the good of our health, but that
we could not apparently build good stoves for our health. Those days are
long gone. We can easily build very clean wood or other biomass stoves that
do not produce char. The original argument has fallen away, first to fan
stoves and then to a new generation of natural draft stoves.

 

As many of the touted stoves that produce char (but not all) cost more than
people are willing to pay, the carbon trading folk are devising methods of
subsidising them from CDM sales or the Gold Standard markets. This is, long
term, a risky proposition upon which to base a business plan because the
carbon market is looking shakier by the year - and that has nothing at all
to do with the worthiness of carbon/climate arguments, it is purely
economic. There is a window which is rapidly closing. After about 9 more
months, that window will close. If you want a CDM funded stove programme
(which is a very expensive thing to create and moderate) it will have to be
submitted by July next year. After the end of the Kyoto Accord there is no
plan in place to continue it. Many countries and most notably China and
Japan have said they will definitely not participate. As China's per-capita
carbon emissions exceed the USA's (or almost -will be true soon) they are a
gigantic emitter and if they are not playing along in the carbon trading,
the other countries will find they cannot compete economically. CDM
contracts will run at a maximum to 2020. After that - zilch for burying a
few grams a day of char from a stove. We can't tell exactly what happen 9
years from now, but you can bet that if the temperature continues to drop in
the USA (winter temp is presently falling at 3.8 deg per decade) there will
be little enthusiasm from the USA either. That leaves Europe and they can't
go it alone. Too expensive.

 

So..if you want to promote char making stoves for agricultural reasons, and
you do not want to be accused of making the biomass shortage worse than it
is already, you will have to show that you are using a) a fuel that is not
currently being used (and wasted) or b) you are using a fuel so economically
that the total fuel required is reduced, or c) that you are balancing your
stove programme with a tree planting/ resource-creating activity that goes
with it.

 

In physics there is no free lunch. If the stove does not save fuel and
produce char on the side, it is going to face programmatic problems. Such a
thing is possible, but if have no carbon argument, you are left with fuel
efficiency. Any stove that burns the whole fuel is going to outperform any
char producing stove. Simple as that.

 

If biochar turns out to be a winner in all cases, or most, it will
definitely be more efficient to produce it under controlled circumstances
near the source so only the carbon is shipped, not the rest of the matter
and moisture in it. That is simple math.

 

If you happen to have some char production, by all means throw it into the
ground near something that will benefit from it. But it would be better to
put it into the next fire and get that sweet heat without having to lift
another finger, or axe.

 

Regards

Crispin

 

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