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Re: *** PROBABLY SPAM *** Re: GSBN:A question about quantification of carbon sequestration in a bale and bale structures
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- Subject: Re: *** PROBABLY SPAM *** Re: GSBN:A question about quantification of carbon sequestration in a bale and bale structures
- From: André de Bouter forum@...
- Date: Tue, 29 Aug 2006 19:57:21 +0200
- Reply-to: "GSBN" GSBN@...
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Hello David et al,
I agree with Derrek and Bruce that the energy saved in the long run is
(most likely) more interesting than the carbon stocked in the bales. I
say "most likely" because I have not seen very clear numbers on this
subject yet (I have not looked for them either, I admit).
However, I've understood that carbon sequestering takes into account the
carbon in the material, but also calculates the energy used to build.
And I'm sure I don't need to convince anyone on this list that this IS a
point to take into account when talking about ecological building.
The french document I referred to compares a 280mÓ professionally built
office building (post and beam/straw bale infill/no plaster but wooden
The SB version 'uses' 3,7 tonnes of carbon (=13,6 CO2)
The metal structure/sheeting version would produce 43,4 tonnes of carbon
The concrete version (polystyr?ne insulation) would produce 52,5 tonnes
In the case of this particular SB building its life has not been very
long. It was burned down (by a well planned and executed criminal act)
just before electrical wiring was done. So I guess finally its Carbon
Balance ended up a little to the negative side instead of 52,5 negative
(+ toxic gases)
In Holland we say: "Those who won't honor the little (things) don't
deserve the big (things)."
I agree with your observations in general, although I think that the delay of on average probably five decades or more of that release of many tons of atmospheric carbon for each sb house is part of the contribution of sb construction to dealing with global warming that shouldn't be ignored. All the straw that isn't burned but instead is stored in the walls of buildings for decades is an offset at a time we are wrestling with ways to reverse the trend.
In a way this reminds me of the argument I've heard that embodied energy in a building is dwarfed by the operating energy and so is insignificant and can be ignored. I think that the embodied energy is typically quite significant by itself, meaning that operating energy is enormously significant...in other words, I agree that the ratio is important and we need to focus our actions where we get the most effective results, but that doesn't justify ignoring significant impacts because they are smaller relative to other impacts, or in this case I think, not claiming a benefit that comes along as part of what we're already doing. It is just one more benefit, not the primary one, in my view.
Kelly's info from the study of Chinese straw bale houses versus their brick counterparts, and any credible research and evidence showing the energy use reduction potential of sb are a valuable contributions to the overall benefits of sb construction.
Sent: Tue, 29 Aug 2006 7:26 AM
Subject: Re: GSBN:A question about quantification of carbon sequestration in a bale and bale structures
My memory of the carbon sequestration analysis on the Chinese and Mongolian
strawbale structures, is that energy conservation dwarfs the impact of the
carbon stored in the straw. The few tons of carbon in the bales themselves
are part of the current carbon cycle, where plants grow and take in carbon
from the air, then die and release the carbon as they decompose. This
cycle causes no net change in the atmospheric carbon levels.
While the bales in a house might delay the straw's decomposition by a few
decades, I don't think that we can expect, on average, to lock up much
atmospheric carbon in strawbale houses for very long.
In contrast, every bit of fossil fuel burned brings carbon into the
atmosphere that was sequestered millions of years ago. Fossil fuel use has
caused the dramatic increase in atmospheric carbon dioxide, over the last
century. The biggest impact of a strawbale home will be energy
conservation, leading to decreased use of fossil fuels. This will vary
with the climate and the success of the design and construction.
Decreasing fossil fuel use, over the life of a strawbale home, is likely to
involve vastly more carbon that that which is in the bales. And all the
carbon "saved" will be fossil carbon, which would otherwise have directly
increased the amount of carbon in the atmosphere.
I think that carbon sequestration is one of the weaker claims for strawbale
building. On the other hand, energy conservation is variable with climate
and structure, making general numbers impossible. Quantifying either of
these things isn't easy.
--On August 28, 2006 9:44:09 PM -0400 strawnet@...:
> Hi all,
> A friend who we've been working with who is involved with Native
> American renewable energy projects and also affordable energy-efficient
> housing for Native Americans just inquired about carbon sequestration in
> bales and bale structures. I know that there has been research done on
> this and that some folks have done work related to getting carbon trading
> credits for bale structures but after hunting around a bit here I can't
> seem to lay my hands on that info and wondered if anyone on the list has
> credible data and sources of information about that?
> Thanks for any help any of you might be able to provide.
> Warmest regards,
> David Eisenberg
Language Learning Center
Ortega Hall 129, MSC03-2100
University of New Mexico
Albuquerque, NM 87131-0001
505/277-7368, fax 505/277-3885
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