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Re: [Strawbale] Embodied Energy, Carbon research of Big Bales...

Hello carbon heads,
If we use the principle of subtracting the temporarily 'stored' carbon from the used carbon we are actually saying : Just add a big room filled with wood to your project to deal with the carbon used (to produce the cement etc.) I believe we need to mention the used carbon, plus the carbon needed for the next 50 years of heating and cooling plus the 'stored' carbon instead of just 1 number. Which reminds me of a sequence in the book 'The hitchhikers guide to the galaxy': Very intelligent mice build a mega computer so it can tell them what is the secret of Life, the Universe and Everything. After many years of calculations the respond is 'YES'. The answer is probably correct, but not very informative.
Also, isn't 'bragging' about storing carbon actually sayin': look how much product I used, that now nobody else can use for other purposes. 

Andrà (got more questions than answers) de Bouter
France



Max Vittrup Jensen a Ãcrit :

Hiya,
Thank you, Rikki Nitzkin, for initiating this discussion about embodied energy in straw bales.
It so happen to be that Canadian FranÃois Gonthier-Gignac and I are in process of developing a tool to promote cleaner ways of building through optimizing Embodied energy, energy efficiency and costs in residential housing. It's part of our Environmental Management/Sustainable enegry studies at Aalborg University, in Denmark. 

Our case study so far has the following research question:
"How to measure/assess the environmental and energy savings of a Big Bale Building when compared to conventional residential passive house construction ?"
We are now in the process of gathering data and we'll welcome relevant information and links, if any of you have some good ideas: We'll get back with the results to you in January '08.
And here's my 2 cents to the well considered answer by Rob Tom: All your reflections are very relevant. However put to the task of coming up with an amount of kilo joule which goes into 1 single big bale, my approach would be to find out how many big bales an average (European) baling machine make per hectare, and find out the liters of diesel consumed. These figures should give the individual answer. The LCA (Life Cycle Analysis) tool then also need some figures for transport to storage and to site, and we'll have to give some estimates; typically not more than 25 km in Europe. [Following the doctrine of not building an igloo in Sahara, nor a SB in the deep forests]. To me this would give the figures, though I'd at any time support Brians view: That the Bales are simply stored while in the house and will eventually return to soil, and thereby off-setting other building materials...making it carbon negative. 

Sincerely,
Max Vittrup Jensen
Natural Builder and Human Ecologist...
PS: For the record: I really don't like LCA tools!!!!


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Today's Topics:

   1. Fw: [Strawbale] RV: [Paja] Datos sobre una bala de paja
      (Brian Waite)
   2.  Carbon (Brian Waite)
   3. Re:  RV: [Paja] Datos sobre una bala de paja (Robert Tom)


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Message: 1
Date: Sat, 3 Nov 2007 12:51:18 -0000
From: "Brian Waite" <brian@brianwaite....uk>
Subject: Fw: [Strawbale] RV: [Paja] Datos sobre una bala de paja
To: "European strawbale building discussions"
	<strawbale@amper....muni.cz>
Message-ID: <002801c81e18$3a9bda40$0ae12950@bitzspecial>
Content-Type: text/plain; charset="iso-8859-1"
----- Original Message ----- From: Brian Waite To: European strawbale building discussions Sent: Saturday, November 03, 2007 9:50 AM 
Subject: Re: [Strawbale] RV: [Paja] Datos sobre una bala de paja
It is argued by some more qualified than myself that because carbon is locked into the straw during its growth, that carbon is effectively "banked" thereby offsetting the carbon in the other building materials so that a strawbale building can have a 
zero or even negative carbon rating. This line of reasoning seems to me to be more valid than the "offsets" used to cancel out our extravagancies with token gestures.

   Another plus for SB: Research is now showing that because farmers are not allowed to burn off straw, and have to plough it back into the soil, this is creating a problem with soil fertility inasmuch as straw needs fungal action for it to decompose and there is now an excess of fungi building up in the soil, year by year, seriously depleting its' fertility. Brian www.strawbalehouse.co.uk
----- Original Message ----- From: Laimis Zmuida To: European strawbale building discussions Sent: Friday, November 02, 2007 5:25 PM 
  Subject: Re: [Strawbale] RV: [Paja] Datos sobre una bala de paja


  Hello,

  It's hard to make exact calcullations, because it is very complex phenomenon. But there are some approximate figures. It is called embodied energy.

  Here are the tables:

  With straw:
  http://www.canadianarchitect.com/asf/perspectives_sustainibility/measures_of_sustainablity/measures_of_sustainablity_embodied.htm

  Without straw:
  http://www.greenhouse.gov.au/yourhome/technical/fs31.htm



  Laimis Zmuida
  Straw bale buildings in Lithuania - http://blogas.lt/siaudunamai
2007/11/2, Rikki Nitzkin <rikkinitzkin@earthlink...>: I have gotten a request for exact figures on 
    -how much energy is spent in producing a bale
    -how much CO2 is produced by it

    can anyone help?




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Message: 2
Date: Sat, 3 Nov 2007 18:22:07 -0000
From: "Brian Waite" <brian@brianwaite....uk>
Subject: [Strawbale] Carbon
To: "European strawbale building discussions"
	<strawbale@amper....muni.cz>
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----- Original Message ----- From: Brian Waite To: European strawbale building discussions Sent: Saturday, November 03, 2007 9:50 AM 
Subject: Re: [Strawbale] RV: [Paja] Datos sobre una bala de paja
It is argued by some more qualified than myself that because carbon is locked into the straw during its growth, that carbon is effectively "banked" thereby offsetting the carbon in the other building materials so that a strawbale building can have a 
zero or even negative carbon rating. This line of reasoning seems to me to be more valid than the "offsets" used to cancel out our extravagancies with token gestures.

   Another plus for SB: Research is now showing that because farmers are not allowed to burn off straw, and have to plough it back into the soil, this is creating a problem with soil fertility inasmuch as straw needs fungal action for it to decompose and there is now an excess of fungi building up in the soil, year by year, seriously depleting its' fertility. Brian www.strawbalehouse.co.uk
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Message: 3
Date: Sat, 03 Nov 2007 13:24:12 -0400
From: "Robert Tom" <ArchiLogic@yahoo...>
Subject: Re: [Strawbale] RV: [Paja] Datos sobre una bala de paja
To: "European strawbale building discussions"
	<strawbale@amper....muni.cz>
Message-ID: <op.t077ymci291bzk@edg-2wjjz8rsqjd>
Content-Type: text/plain; format=flowed; delsp=yes;
	charset=iso-8859-15
On Sat, 03 Nov 2007 05:50:38 -0400, Brian Waite <brian@brianwaite....uk> wrote: 


a strawbale building can have a zero or even negative carbon rating.
Another plus for SB: Research is now showing that because farmers are not allowed to burn off straw, and have to plough it back into the soil, this is creating a problem with soil fertility inasmuch as straw needs fungal action for it to decompose and there is now an excess of fungi building up in the soil, year by year, seriously depleting its' fertility. 


  2007/11/2, Rikki Nitzkin <rikkinitzkin@earthlink...>:
    I have gotten a request for exact figures on

    -how much energy is spent in producing a bale
    -how much CO2 is produced by it
I won't provide any figures for the embodied energy of straw bales simply because the variables are too wide-ranging to nail it down to any discrete amount.
For instance, in countries where straw is cut and baled by hand and then used in the immediate vicinity, the EE numbers will be substantially different than say, rice straw that is cut and baled in Texas or California where it is likely that huge tractors that are bigger than the homes of many people on this planet were used and then the straw might be trucked a hundred miles or more to the building site.
And it could easily be argued that since no one actually grows straw for the purposes of harvesting the straw, and since straw bales are a by-product of cereal grain production, the EE of strawbales could be considered to be negative. But I won't go into that.
The problem of soil fertility due to excess fungi (mentioned above) sounds spurious.
The initial stages of decomposition of straw and other carbon-rich materials like sawdust, wood chips requires nitrogen. 

Nitrogen is a nutrient that is essential to plant growth and green leaves.
When straw is ploughed back into the soil, the initial stages of decomposition depletes nitrogen from the soil at the expense of any plants growing in it. Nitrogen-starved plants may be weak, growth-stunted and tinged with yellow, all of the signs of poor plant vigour. Once the straw has decomposed, it is beneficial to soil health and structure and subsequently, to any crops growing in it. But that decomposition cycle usually takes longer than a single crop-growing season and land costs being so high, no farmers can really afford to let fields lay fallow so if nitrogen fertiliser is not added to the soil, crop health will suffer.
Traditionally, straw was taken off and used for animal bedding so that it would be mixed with nitrogen-rich animal urine and manure before it was returned to the soil, hence no nitrogen depletion. 



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