Normalization and weighting

Question

I'm super new to LCA but have a question. I've performed an analysis to identify the life cycle of different solvents. I selected the different solvents and used the EF 3.1 which granted me a significant table of data.
I was searching for a way to weigh the data when i stumbled across a document of the European comission (https://eplca.jrc.ec.europa.eu/permalink/2018_JRC_Weighting_EF.pdf)
Is it correct that i can just take the raw data from the EF and multiply it by the weighting factors determined by the EU, and use the sum of the outcome as a level of greenness for the different solvents?

e.g.
ozon depletion = 1.01 kg CFC11 eq, weighing factor = 22.19 so ozon depletion accounts for 22, whilst water use is 0.9 m3 with a weighing factor of 9, accounting for 2.7?

I found some papers about normalizing the data first, but i'm not sure if the data has already been normalized during the analysis.

thanks!

Answer 1

Hi,

if you use our method package, we provide the normalization and weighting factors proposed by the JRC. So you can use them directly. Have a look at our manual https://greendelta.github.io/openLCA2-manual/lcia_methods/impact_methods_tab_contents.html?highlight=normalization#impact-assessment-methods-tab-contents and how to 'activate' this option: https://greendelta.github.io/openLCA2-manual/res_analysis/index.html?highlight=normalization#calculation-and-result-analysis.
This will allow you to normalize and weigh your solvents down to a single score. You can also do it in 'Projects' and add single score bar charts to the report. The result gives you a single value and you can compare the more sustainable option. But take care, the single score method is not ISO 14040-44 conform and the JRC's weighting/normalization factors should be used with care.
Best