Regionalized Calculation active causes negative values [ecoinvent in OPENLCA]

Question

Hello there,

I'm doing a series of tests. I defined two simple processes in OpenLCA, and as location I defined "Portugal - PT". When I evaluate the Product system for "Land Use", using ecoinvent, I get the result of figure 1 (which seems ok):

However, when I activate "Regionalized Calculation", I get the same result but with a NEGATIVE value (figure 2). My question is: why the negative value if nothing changed except the regionalized calculation, which seems already accounted for without ticking the option?

Thank you in advance

Answer 1

Hi,

the ecoinvent database itself has no regionalized characterisation factors. So, using the option is not helpful. Please have a look at the regionalisation chapter: https://greendelta.github.io/openLCA2-manual/advanced_top/regionalized.html.
Hope this helps

Comments

I want to correct that it is still helpful, because the difficulty and complexity in regionalized LCAs is the regionalized inventory results (LCI). Compared to other tools, openLCA can automatically calculate regionalized LCIs for all databases by ticking the regionalized calculation option, even if the flows and exchanges of the database are not regionalized.

Getting the regionalized environmental impact (LCIA) in the next step, of course, needs a regionalized LCIA method as available in our openLCA methods package, or the user must simply multiply the factors themselves to the LCI results.

When you do not have used a regionalized LCIA method, the regionalized LCI result (as in your case for PT) will be multiplied with the unregionalized characterisation factor. So you will get the same environmental impact result for "Land use" as when you do not tick the option, plus you will get and see the regionalized inventory.

However, I want to know why you have a negative result there. Land use should be always modeled on the input side (occupation, transformation to, transformation from), as this is a convention used by ecoinvent and some other (not all) databases. Maybe you have not modeled all land use elementary flows on the input side?