Electricity in LCA
The issue of accuracy
In LCAs electricity has a dominant contribution, not only in the use-phase, but also in the production of the materials. The percentage of CO2 emissions from electricity for metals production (Ecoinvent V3, “cut-off” database) is in the range of 30–56% (e.g., Aluminum 56%, Copper 35%, Gold 36%, Lead 30%, Nickel 31%, Silver 52%, Zinc 50%). For woven textile (Polyester, 70 dTex) the percentage is higher (70–80%).
For calculations on battery electric vehicles (BEVs) and the production of electrolytic Hydrogen, the choice of data for electricity is crucial.
Common practice in LCA for household appliances is that the average consumption mix is applied for a country or a bigger region (reasoning: these appliances are used all over Europe, USA, or the World), except for specific cases (ex-post LCAs like EPDs) where predominantly the country consumption mix data are taken. However, an analysis of 38 papers on LCAs of washing machines (search in Scopus on ‘LCA washing machine’) revealed that in more than 80% of the papers the origin of the electricity was not specified, which suggests that the author was not aware of the big differences in data on electricity.
There is a general feeling among LCA practitioners that data on electricity are rather accurate in LCI databases. Therefore, they take the electricity data for granted.
Only specialists know that there are issues with data quality. Product Environmental Footprint Category Rules (PEFCRs) for the European market are not yet available for electricity nor for hydrogen. Therefore, it is not strange that there are inconvenient differences between well-established LCI databases like Ecoinvent, Gabi (PEF), and ELCD. This webpage deals with some practical issues to enhance the accuracy of your LCA calculation with regard to electricity. A detailed analysis can be found in (Olindo et al. 2021).
The relevance of the issue is clearly shown in Fig. 5.10a. This figure depicts the GHG emissions per km of cars (BEV and fossil fuels) for the EU countries in 2013.
Figure 5.10a. GHG emissions per km of BEV and fossil fuel cars in the EU, data 2013. (Moro et al., 2018)
- LCA, the basics
- Rigorous LCA
- “Fast Track” LCA
- LCI structure
- EoL and Recycling
- The issue of allocation
- LCA of services
- Eco-costs estimate EPDs
- Electricity in LCA
- GOs and RECs in LCA
- Wood LCA issues
Fig.5.10 suggests a higher accuracy than that the reality is: (1) the height of a bars of a specific country is up to 30% different in Ecoinvent in comparison with Gabi (2) the emissions are now considerably lower than back in 2013, where the reduction is different for each country (in 2016 11% less for the average in the EU, 34% less for Denmark,and even 38% percent for the UK).
So the real picture might be quite different.