List:
ETHOS 2014 Thoughts
(a data dump - see also two earlier on first two days - none of my
thoughts there. Hope others will add their thoughts - especially those who
were going on to Cottage Grove for three-four days of further dialog
This mainly being done to keep Tom Miles and daughter Erin up on events
at ETHOS. I learned from Tom’s sister there was nothing serious about their
having to drop attendance. We missed them.
The following in italics uses format at
http://www.vrac.iastate.edu/ethos/conference.php
Up to now this conference largely run by Mark Bryden, with help from
Dean Still. Now a new Board elected (6-8?). The following taken from the
above web site.
Conference Themes (Five)
A. Lab research, including:
insulative materials, Mainly talks by Jon/Flip Anderson. These are
floating bricks. Looked very nice. (hard, vitreous, but light) Use 50-50 mix
of clay and sawdust (by volume). Not sure of firing temperature. I talked
some with Alexis Belonio on replacing sawdust with char (we will both try
different sizes downward from pellets). Others are making such bricks also.
Char being of interest because it is easy to get everywhere.
Much discussion on whether ceramics are mandatory for long life, as
no/few/expensive metals can stand up to high temperatures. TLUDs believed to
experience considerably lower temperatures. Belonio says you are OK with
metals in his stoves if metal doesn’t get red hot.
I was surprised that Jon and Flip often use unfired material for their
stoves. Sacrifice efficiency (because of high density) for low cost.
Belonio and I had several discussions about making light-weight
refractory cement (not clay) stoves. He emphasized need for considerable
silica to get high temperature strength - easily available from rice husk ash
(not rice husk char). We will both try char as an ingredient. I have
successfully used concrete blocks for TLUD operation (but no life tests).
Cement could be simpler to construct at remote villages.
Considerable emphasis on needing to cut costs a great deal for cooks
using three-stoves - which are often better than the claimed new stove.
efficiency testing, Some new lower cost equipment coming from Aprovecho.
Four of new regional testing centers there (Nepal, Senegal, China, XX). I
think these regional centers will be big help in getting more involvement by
knowledgeable combustion/pyrolysis experts.
emissions monitoring, Same for Aprovecho (Sam Bentson). Report that he
had achieved all 4’s for Tiers with a charcoal using stove. Main secret was
paying attention to reflectivity.
safety updates and design issues, Safety not covered explicitly but
several reminders that it is one of eight areas getting a tier rating.
The idea of thermal diodes (heat pipes) did not come up at Ethos- but I
talked about this with several people, because of dialog on a different list.
The idea could allow multiple cook pots on a single central flame - for either
TLUDs or rockets. Look this up on Wiki and the idea should be easily
understood. Idea in use in many solar devices. I don’t think in any biomass
cook stoves. (True?) Used along Alaska pipelines by the tens of thousands (to
keep permafrost).
More rocket stoves seen using vertical wood pieces, with “automatic”
feeding. Dale Andreatta is finding there is an optimal angle for the grate
depending on fuel dampness.
The Save 80 stove (German) had good looking design for sunken pot
(skirt design looked right). They are selling a complete package - stove,
pot, haybox. This violates the “principle” of having $10 stoves - but just
might give the lowest annual cost. Can’t use this stove for some higher
temperature cooking - but saw photo of frying eggs
One example (Kirk Harris) using a sacrificial insert (too soon to
report anything) - but increases cost by less than 50 cents - and could add
years to lifetime (with replacements only when needed).
I heard very little on chimneys this time.
Agreement (?) that ceramic grates for rockets were much better than
metal.
gasifier advances, Belonio showed several videos of very blue flames.
I received conflicting guidance on why blue occurs. Belonio reported that his
burner cap design was developed for potential buyers in place he has been
working (Philippines, Indonesia, XX) have strongly favored LPG stoves - and
they all had the multiple small holes in rings. To get acceptance of wood, he
needed his stove to replicate the LPG “multiple “flamelet” design. He knows of
no other stove design using this approach (not possible with rockets, but all
TLUDs could).
Dean Still especially was complimentary of new design idea from Kirk
Harris who presented and demonstrated on several approaches to point secondary
air downward (with a third controllable supply). Someone said that the
Phillips stove had something similar with downward pointing secondary air (and
they invested extensive engineering expertise ) with fans.
Disagreement on whether to add insulation in place of open channels for
preheating secondary air with TLUDs. Kirk Harris collecting data soon to (he
believes justifies insulation over preheat). We see both approaches also with
rockets.
hayboxes/insulative cookers, This is an old idea,. Aprovecho has
pamphlet. Can be done anywhere at low cost with about 50% fuel savings (or
more). One demonstration given. Stove companies and GACC need to get more
behind this, because of potential big savings in fuel.
solar cookers. Essentially nothing this year. Considerable discussion of
large use of wood for water heating, which can be done during the day. Need
more on hybrid systems.
B. Field experience, including monitoring of: performance, indoor air
pollution exposure, health impacts, user satisfaction, time and socio-economic
impacts; awareness raising; stove promotion; involvement of volunteers and
local universities; lessons and modification to approaches.
Several talks along this line. I think general agreement that in-field
surveys may not be really capturing use of new stoves accurately. Agreement
that existing water boiling tests are not indicative of what happens in real
kitchens - but I saw no data on how far apart they are - and such comparisons
should be relatively easy.
Paul Anderson mentioned an upcoming leasing program ($0.33/mo
[$4/year]), in exchange for 200 gms char per day average. (char to go in soil)
Uganda?
Missing were talks by folks at CSU (budget problems), who along with
Aprovecho, have sizable grants from DoE. Some but not enough from Dean on what
Aprovecho has learned in that DoE program (he is writing a report).
Elmar Dimpl (working with GIZ (?) with regional test center in Senegal)
reported on unsolved problem of badly polluting a large part of capital city
Dakar by smoking fish. (big export item for Senegal.) Later discussed with
several as we looked at an (intentionally) smoking TLUD. Thinking one can make
char while creating smoke. Major health issue now for women tending (flipping
the fish) over long raised “trenches”. Anyone have solution?
Short discussion on finding ways to better use cell phones in stove
field testing, etc.
C. Efficiency versus effectiveness, and resulting design implications.
Michael Johnson and a few others from Winrock and Berkeley Air had
interesting new material on how to go between stove tiers and WHO standards for
amount of permissible cooking at different tiers to meet the WHO standards for
CO and PM2.5. Would end up with recommendations for using different stoves for
different tasks to minimize daily exposure to pollutants. (Agreement that new
stoves do not replace transitional stoves.) This process driven by health
issues, not so much efficiency or climate (I think) - but could.
D. Technology standards: key parameters, constraints.
I talked twice with Drs. Ranyee Chiang and Michael Johnson, who seem to be
the main international leaders in this stove standards effort. There is a
meeting in Nairobi (?) very soon, where they will go into detail not possible
in a few minutes at a meeting like Ethos. I mentioned my desire to see more
on a) lab testing reporting time use by testers, b) stove lifetimes, and c)
annual costs.
E. Policy issues: role of U.S. partnerships and international donors,
country-level leadership, subsidies versus commercialization.
One nice new feature was two people from Cummins - there to see if it
made sense for this (big) company to become more active in GACC activities. I
hope they and others do join.
GACC activities explained by Ranyee, Julie Ipe - on documentation at
GACC, and John Mitchell of EPA, woking closely with GACC. Best understood by
going to GACC site (a big news item was that they will soon add a catalog of
stoves.) I believe progress still being made in increasing funding.
Had several long talks with Ted Redelmeier of Toronto, who gave
Saturday 20-minute breakout talk on big picture use of stoves to make charcoal
(later called biochar) for climate reasons. Introduced new (to me) terms of C-
- and C++ Ted uses latter to identify fossil releases into atmosphere, with
C- - as the sequestration possible from char-making stoves.
Sum up: I hope others will add their take-aways - for the benefit of those who
couldn’t make it. Ron_______________________________________________
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