System expansion: "avoided product" not calculated

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Mara
Posts: 8
Joined: 04 Apr 2016 12:46

System expansion: "avoided product" not calculated

Post by Mara » 08 Jun 2016 09:38

Hello openLCA users!
I have a problem with making openLCA calculate the production of avoided products in the inventory. I am modelling the life cycle of a machine from cradle-to-grave. During the EOL/Disposal phase some of the plastic and aluminium used for the machine's components can be recycled, i.e. some production of new plastic, aluminum and energy is avoided. I followed the instructions on this website: http://www.openlca.org/documentation/in ... _expansion , i.e. I ticked avoided product for the outputs mentioned above. However, if I connect the providers for these outputs in the model graph, no dashed lines occur to connect the processes (see pictures), i.e. the connections to "aluminum, secondary rolled", "Polypropylene granulate" and "waste incineration of plastics". Now, the production of the avoided products is not calculated as beneficial.
Does somebody know why that is the case and what I can do to make openLCA consider the positive impacts of the avoided products?
Thank you very much!
Best,
Mara
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mohifalahi
Posts: 7
Joined: 08 Feb 2017 10:58

Re: System expansion: "avoided product" not calculated

Post by mohifalahi » 15 Apr 2017 22:56

Hi Mara,

I have an experience with "avoided product" with openlca, actually the avoided emission of electricity production from landfill gas capture.
1- By trial and error, I found out that when the entire supply chain of the main process is available, the "avoided emission" take into account. But also by searching for the avoided emission on "Model graph", nothing found. I didn't find also the contribution of avoided product in LCIA(Contribution) excel tab.

2- I found out that the electricity production as avoided one, should have a minimum value; otherwise the results have no difference with "no system expansion". (however the value I added as avoided product is not an actual and true measure based on my data -- this is still my unsolved problem)

Regards,
Mohammad

aciroth
Posts: 750
Joined: 09 May 2010 23:28

Re: System expansion: "avoided product" not calculated

Post by aciroth » 17 Apr 2017 13:23

Hi Mohammad,
thank you for your contribution, not sure I understand -
1) yes, avoided product takes the entire supply chain of the avoided product into account, but also, it is visible in the model graph, sees screenshots below
2)
electricity production as avoided one, should have a minimum value; otherwise the results have no difference with "no system expansion"
- here, you lost me. Of course in the avoided product calculation in openLCA, any amount can be used. See also the screenshots below where I changed the amount from 1MJ to 10 MJ which results in 10 times higher (in absolute values) impacts.
Best wishes,
Andreas
Attachments
2017-04-17 12_17_13-openLCA 1.6.2.png
adding an avoided product
2017-04-17 12_17_13-openLCA 1.6.2.png (21.79 KiB) Viewed 1149 times
2017-04-17 12_21_18-openLCA 1.6.2.png
process with avoided product in the model graph
2017-04-17 12_21_18-openLCA 1.6.2.png (7.39 KiB) Viewed 1149 times
2017-04-17 12_53_33-openLCA 1.6.2.png
the supply chain in the model graph
2017-04-17 12_53_33-openLCA 1.6.2.png (22.07 KiB) Viewed 1149 times
2017-04-17 13_17_15-openLCA 1.6.2.png
LCIA results, 1MJ avoided product
2017-04-17 13_17_15-openLCA 1.6.2.png (27.79 KiB) Viewed 1149 times
2017-04-17 12_24_35-openLCA 1.6.2.png
10 MJ avoided product
2017-04-17 12_24_35-openLCA 1.6.2.png (19.39 KiB) Viewed 1149 times
2017-04-17 12_59_47-openLCA 1.6.2.png
LCIA results, 10 MJ avoided product
2017-04-17 12_59_47-openLCA 1.6.2.png (27.6 KiB) Viewed 1149 times

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