regarding double counting logic (??) of None allocation in OpenLCA

Question

Hello,

I came across the following discussion the other day:

"When there a co-products in a process and “none” is chosen for allocation, the process is double counted in the Tec-matrix (all flows exempt the product and coproduct of the process are double counted). Is this by purpose? Wouldn’t it be more coherent to automatically allocate 0 impact to the co-product?" (see original post: https://ask.openlca.org/2281/allocation-in-multifunctional-processes)

My question is: is this ("risk of double counting") still the case for the latest OpenLCA software? I'm concerned someone may inadvertently leave allocation to None when there are co-products, which can lead to a significant overestimation of the results.

Thank you

Answer 1

I would say this is not a bug but intended. If you do not apply allocation (or system expansion / avoided product approach), all impacts of the process are attributed to each product. This is LCA "logic". Setting a default impact to 0 is quite optimistic and leads to underestimation of impacts. That said, it is reponsibility of the modeler to deal with multi functional processes, and the modeler should not trust that this is addressed somehow automatically.

Comments

good point, we will do that