[Stoves] News (CCF 2017): Blame the rural poor for Delhi's ills

[Nikhil Desai]

Crispin:

Again, please don't confuse heating stoves with continuous use and
cookstoves with freedom to choose timing, duration, power levels.

With heating stoves, MJd per day are fairly high, heat loss from stove
materials or a cooking pot on top is valued. There may be flexibility with
MJd depending on how cold it is outside, and by time of day, but the
variance is just not that high.

With cookstoves in India, Kirk Smith (with Jennifer Peel, 2010) cited a
paper from measurements in north Indian villages of PM2.5 exposure of 6-12
mg/day. (I don't know if these were direct measurements of computed from CO
emission rates. Could have been concentrations multiplied with 18 m3/day
breathing volume by standard humanoid.) Then WHO used a 330 mcg/m3
concentration for all women in the world supposedly using "solid fuels",
which would give daily intake of 6 mg.

Now with a solid fuel cookstove with high emissions during first ten
minutes of ignition, three ignitions per day, would yield one averaged
emission rate, then put through the mumbo-jumbo of single box would produce
some concentrations, which then put through the IER curves would produce,
um, relative risks, deaths and DALYs.

Think of a heating stove. A single-box or a three-box circulation model is
arguably "representative"; poor people don't live in large homes with open
windows and running space heaters or air-conditioners. (Does happen for the
rich.) Depending on the volume and rate of heat required, I imagine a
heating stove can be available in 2-3 designs and controls, even a
thermostat. Having a rating for efficiency is as useful as for a passenger
vehicle, and even for emissions it is useful if ventilation can be
reasonably controlled; nights used to be smoky in Europe, northern US or
Canada, and other cold cities (Kabul still is), but more outside than
inside. Putting pollution out is a good recourse unless the ambient air
pollution is too high, as the recent efforts of London Mayor indicate.

I will change my view when I have some facts - or even a fact-based model
estimate whose assumptions can be validated - that show that a cookstove,
usable one to eight hours a day, to cook 1 to 10 kg of food, with locally
used unprocessed biomass, produces predictable reduction in aggregate fuel
use or aggregate emission loads.

Mind you, the whole theory of "deforestation", "pollution", is based on
AGGREGATES, and that for DALYs is based on 6 mg/day ingestion with no
allowance for ventilation as chosen by the user. Any claims by stove
protocols that their results and ratings mean anything at the aggregate
level are entirely spurious.

In short, standardized protocols for "international comparability" are
exercise in persuasion as far as cookstoves go. How many people can be
fooled how long is a matter of Monte Carlo simulations and Bayesian theory,
of which I now remember practically nothing.

It is precisely for Kirk Smith-type dogma that I have an aversion to target
emission rates. I would like to see some AWMA-types to get into regime
control by EPA and its contractors, collaborators, and WHO funders.

Nikhil


On Fri, Oct 27, 2017 at 4:18 PM, Crispin Pemberton-Pigott <
crispinpigott at outlook.com> wrote:

> Dear Nikhil
>
>
>
> *>*Setting "international standards" for PM2.5 in mg per MJd is a waste
> of time. .
>
> Here we disagree. Again. I found this metric to be useful for setting
> procurement requirements for the Ulaanbaatar City Clean Air Project
> (UB-CAP) because it can be related to a *proportional* decrease in
> emissions from small domestic stoves eligible for a subsidy. The baseline
> performance replicating a typical ignition and refueling sequence was 680
> mg/MJ delivered into the home.  The project was planning initially (2007)
> to require any stove to reduce this by 30% with a funding of $15m available.
>
> Initial testing of candidate stoves was depressing. The majority of
> ‘improved stoves’ merely increased the thermal efficiency by a small
> amount, but the combustion was no better, sometimes worse (as much as
> double the emissions). Clearly we needed to shift gears on the technology
> employed.
>
> For some time we tried downdraft stoves which were dramatically cleaner –
> certainly in the 90% range or better. A singular advantage of the DD stoves
> was they could burn the crummy ‘semi-coke’ briquettes that everyone kept
> throwing at the problem. Emissions from these SCB’s in a traditional were
> frequently worse (up to 35%) than the traditional stove burning raw coal
> because they were so difficult to ignite and refuel.
>
> With the appearance of TLUD stoves available in bulk, things changed.
> There was no need to develop local production capacity in the short term
> but we needed a performance target suited to the task at hand, which was a
> reduction in total emissions. The fuel consumption metric was previously
> thought to be appropriate because it was assumed (incorrectly) that the
> emissions were inherent to the fuel – many people taught this as catechism,
> particularly the Europeans. The appropriate metric was mg PM2.5/MJ
> delivered into the home. This considered thermal efficiency and emissions
> per unit mass burned in a single number.
>
> The target was set at an 80% reduction, far above the initial 30% target.
> The emission target set was 140 mg/MJ using a contextual test sequence
> based on observed behaviour. After one year it became clear from testing at
> the local lab that 90% could easily be achieved, meeting what was then Kirk
> Smith’s universal reduction target necessary to provide a “significant
> public health benefit”. The following year the requirement was raised to
> 90% with <70 mg/MJ the magic number.
>
> The development of stoves assessed on this basis continued locally with
> the GTZ7.1 crossdraft and two of the Turkish “Silver” TLUD’s achieving
> consistent performance below 1.0 mg/MJ. When Kirk wrote a report a couple
> of years ago to the Minister of the Environment saying that only a new
> miracle technology that might achieve a 95% reduction could briefly stem
> the rise in pollution, the stoves already being supported were reducing 98%
> or better and the city air quality had improved up to 65% (depending on
> where you lived). In spite of consistent, multiple proofs through the years
> 2011-2017 that the cleanest burning of all stoves used raw coal, Kirk and
> others are still trying to sell the line that only a total ban on burning
> raw coal can clean up the air.
>
> In the Hebei Clean Air Project, the target is <40 mg/MJNET and we had no
> problem finding stoves to meet that target, all produced within the
> province. I have recently seen a stove designed in Langfang that will
> consistently be under 1.0 mg/MJ, I am sure of it.
>
> Within 5 years I predict that the project (if not national) requirement
> will be <5 mg/MJ which is less than a tenth of the forthcoming EPA target
> for 2021 for heating stoves. This will represent, for Ulaanbaatar and
> Chinese cities, a reduction of something >99% and this can be achieved *without
> changing the fuel*. As you can imagine, this creates some hand-wringing
> in certain quarters among those who had their eye on large subsidies for
> their favourite toys. Some people’s worst nightmare is a super-clean coal
> or biomass-burning stove. Odd, isn’t it?
>
> I believe the metric mg/MJ delivered is an appropriate performance metric,
> assuming all the stove functions required by users can be maintained.
>
> Regards
>
> Crispin
>
>
>
>
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