There are several reasons why we use standardized datasets with emission data for our calculations:
Consistency: Using standardized data ensures that the results of an LCA are comparable to other studies, as all researchers use the same data.
Reliability: Standardized datasets are often developed by experts and are considered to be of high quality, thus providing reliable data for LCA.
Availability: Standardized datasets are widely available, thus making it easier for researchers to access the data they need for their LCA studies.
Transparency: Using standardized data makes it easier to understand and interpret the results of an LCA and also allows others to verify the data and calculations.
Scalability: It is not realistic to ask the suppliers to deliver LCA documents with verification (e.g. EPDs) for each product on the Pickler website since the costs of it are far too high (normally 20k – 30k).
Overall, using standardized datasets with emission data in LCA is crucial to ensure the results are accurate, consistent, reliable, scalable and transparent.
What are the consequences in terms of accuracy?
Based on the level of detail, there are three types that can be compared in terms of accuracy.
Generic (standardized) data with country-mix electricity (used by Pickler)
Generic data with specific sustainable electricity
EPD/ LCA data
Notes by Joost Vogtländer:
The carbon footprint as well as the eco-costs of type 2 calculations are always lower than type 1, although the difference is normally limited to a maximum 20%, since the calculations are governed by the eco burden of Scope 3 (point 1).
The type 3 calculations (e.g. EDPs) are not expected to deviate much more than 10% from type 1. Moreover, they are not per sé more accurate than type 1 or type 2, since often outdated electricity data are applied, with an outdated carbon intensity. Where possible, the EPD is corrected for this error in carbon footprint and eco-costs.
However, the electricity in Scope 3 supplies cannot be corrected, since the amount per source is normally not known. Furthermore, scope 3 is not only the biggest part of the total product score, but it also has the biggest unknown inaccuracies. These accuracies are improved drastically when the product manufacturer has EPDs of its main suppliers.
Sources
The IDEMAT tables that we use have a reference for each data line, available at Sustainability Impact Metrics and can fully be checked in OpenLCA and Simapro, which assures full transparency.
A database for Simapro owners is available for free at Download of databases - Sustainability Impact Metrics
Open LCA software is available for free at Download; IDEMAT database available at openLCA Nexus: The source for LCA data sets(commercial license 250 euro, academic license for free).