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brightway-lca / brightway2-analyzer

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Tagged graphs with non-unitary activities #4

Open aleksandra-kim opened 4 years ago

aleksandra-kim commented 4 years ago

Original report by Anonymous.

Hello, I've been using the function analysis.recurse_tagged_database() to plot my LCA by tags for more clarity. However I've noticed that my biosphere exchanges are multiplied twice which at the end doesn't give the accurate impacts for the tags. However the LCA is run perfectly and give the right value. Because some of my activities don't always have an unitary output, I was wondering if the analysis.recurse_tagged_database() was working only with unitary activities?

Just to give an example: My FU consumed 10 kg of Activity_1 Activity_1 is defined as: output (production)=10kg and biosphere input = 2 kg of CO2 (tag CO2_emissions) The lca calculation will give a final result of 2 kg of CO2 (ok) But the graph generated by the analysis.recurse_tagged_database() function will give an output of 2*10=20 kg CO2... which is inaccurate.. Could you help me with that ? Regards, Josephine

aleksandra-kim commented 4 years ago

Original comment by josephine Demay (Bitbucket: [josephine Demay](https://bitbucket.org/josephine Demay), ).

Sorry I was not signed in when I wrote the message, but it’s me.

aleksandra-kim commented 4 years ago

Original comment by Chris Mutel (Bitbucket: cmutel, GitHub: cmutel).

Thanks, great bug report.

This is fixed for single graph traversals as of 5b253b3, but the multi_recurse stuff added by James Joyce still needs to be patched. Should be done in the next few days.

aleksandra-kim commented 4 years ago

Original comment by josephine Demay (Bitbucket: [josephine Demay](https://bitbucket.org/josephine Demay), ).

Dear Chris,

My name is Josephine and I am currently working as a research engineer at the university of KTH in Stockholm. I am using Brightway2 to perform a LCA about biochar producing cookstoves in the context of smallholder farmers in Kenya.

I’ve been contacting you previously about your bw2 framework, yet my current request has nothing to do with that. Indeed, I am looking for a PhD position starting in Septembre 2020 and would be very interested to do it at ETH. I was thinking that you might be aware about what’s going on at ETH regarding LCA and that maybe we could discuss it together if you have some time?

I am interesting in climate change mitigation solutions in the field of energy or agriculture.

We could discuss that on the phone if you have some time? Best regards, Josephine