How can I calculate impacts of output flows without provider

Question

Hello,

I’m trying to understand the EXCEL from calculating a product system, to observe which processes and flows have which magnitude in the environmental impacts from my process built.  
Do I understand right, that there just have an “impact” inputs flows (with the connection of a provider), and outputs flows which are “avoided” (and therefore are connectable with a provider)?
What happens with output flows (I ask for all: product, elementary and waste flows) which are not “avoided”. As far as I see in this case there is no possibility to link the flow with a provider, and there isn’t an contribution on the impacts from these flows. Do I see it right, and in this case, how do I have to adapt my in- and outputs to make visible the impacts from the output flows generated from my process?
(I’m using openLCA 1.10.3 and the EF database)

Thanks for any explanation.

Cornelia

Answer 1

Hi Cornelia,

several things:

• every flow that appears in the calculation result, be it waste, product or elementary, that is recognised by an LCIA method and impact category, will contribute to this impact category.
• EF is a fully aggregated database; processes are big blocks not meant to be linked further with other processes. Some are not fully terminated due to limitations of the creating LCA software I think, leaving small input or output non-elementary flows, and on the output side, you can then declare them as avoided, but this means you are giving credit for this other product, which is a methodological choice

Let me know please if this answers your questions, thank you

Comments

Thanks for your answer!
It already helped me, but there remains a question:

How can I find waste and product flows recognised by an LCIA method?
I understand that the need this connection, but there are much more flows for choice. In the case of elementary flows, I found in the meantime the adequate ones (in description: Reference elementary flow of the International Reference Life Cycle Data System (ILCD)).

When I open the waste flow in openLCA there is no option to see if there is an impact factor connected (in the case of elementary flows there exist the tab of "impact factor" in the list of assessment methods. Waste flows also should have an "impact factor"?