+1 vote

Just around two months ago I started my analysis (with OpenLCA 1.7, but the same happens with version 1.7.2) of some products systems using the ecoinvent database version 3.4, specifically with the system model "Allocation, Cut-off by classification" and in the form of Unit processes (name of the file: "ecoinvent_34_cutoff_unit_20180314.zolca" - 54521 KB). In this database I loaded the ecoinvent LCIA methods with the file "ecoinvent_3_4_lcia_methods.zolca" - 11290 KB and obtained some results adopting the method ReCiPe midpoint (H). Today, I have realized that on nexus there is another file for the methods named "ecoinvent_3_4_lcia_methods_updated_ZOLCA.zolca" - 8144 KB and adopting the same mentioned method the results are completely different for the 3 indicators: ALOP (two orders of magnitude greater), NLTP and slightly for ULOP. Attached an excel file with the results for 4 product systems (https://ask.openlca.org/?qa=blob&qa_blobid=8468909733385025052). Which are the correct results ? Which should I trust ? (the file "ecoinvent_34_cutoff_lci_up_lcia_20180314.zolca" - 1528212 KB including the methods has remained unchanged).

in openLCA by (290 points)

1 Answer

0 votes
by (50.8k points)
edited by

Hi Frank, not too sure I understand, in Nexus there is only one ecoinvent LCIA method, see screenshot:

We take these methods directly from ecoinvent, and would recommend our more extensive and tested openLCA method pack instead.

..edited because I cannot add pictures in comments: the file name for the ecoinvent LCIA pack is ..JSON_LD.zip

edited again: rechecked, the new version seems correct (i.e. directly reflecting the ecoinvent method), you see this e.g. for ALOP

a bit small but in lila the openLCA method. And you see this also from the contribution in the impact analysis. Of course I have not seen your product system.

And still, from our side we recommend the openLCA pack 2.0.

Best wishes

by (290 points)
Yes Andreas, beyond the screenshot and talking about the file which is downloaded, the name of the file is currently "ecoinvent_3_4_lcia_methods_updated_ZOLCA.zolca" with the dimension of 8144 kB.
Previously, at the same identical link of the screenshot, the file downloaded was different: the name was "ecoinvent_3_4_lcia_methods" with dimension of 11290 kB, which I have on my pc and I can send to you for checking.   If you could keep a log of the modifications of the versions it would be great.
Regarding the openLCA LCIA methods pack, I have read that their use is not very recommended with the ecoinvent db, which has its own methods pack (the above mentioned files).
by (50.8k points)
See please my edited answer above; also not sure where you read that "their use is not very recommended with the ecoinvent db" - we think it is recommended to use the openLCA package, but also it makes sense to provide the original ecoinvent version.
by (290 points)
ok, thanks for having edited the first answer.
Back to the point, you can see that the name of the package (ecoinvent_3_4_lcia) is now "methods_updated", while a previous version (not updated yet) existed, which I used for my calculations.
By the way, I have made the calculations also with ReCiPe Midpoint (H) [v1.11,  December 2014] of the openLCA LCIA methods and the results are different from those of the updated version for the indicators: Climate Change (from +70% to + 180%), Marine eutrophication (around -80%) and completely different for Water depletion (3 orders of magnitude greater) (sorry I can't post the new excel file) .
Therefore, is it possible to know which were the major modifications between the versions of "ecoinvent_3_4_lcia" (updated and not updated) and which is the correct version and which are the correct results regarding the indicators ALOP, NLTP and ULOP (see the relevant differences in my originally attached excel file) ?