Towards Standardized Grid Emission Factors: Methodological Insights and Best Practices

TL;DR

This paper analyzes how methodological choices affect grid emission factor calculations, providing guidelines to improve consistency and accuracy in corporate GHG reporting based on a case study of Germany.

Contribution

It systematically identifies key methodological factors influencing emission factors, quantifies their impacts, and offers best practice guidelines for standardized calculation.

Findings

Methodological choices can alter emission factors by up to 69%.

The case study results align with prior research but show variations up to 34.6%.

Open data sharing promotes transparency and further research.

Abstract

Inconsistent calculation of grid emission factors (EF) can result in widely divergent corporate greenhouse gas (GHG) emissions reports. We dissect this issue through a comprehensive literature review, identifying nine key aspects - each with two to six methodological choices - that substantially influence the reported EF. These choices lead to relative effect variations ranging from 1.2% to 69%. Using Germany's 2019-2022 data as a case study, our method yields results that largely align with prior studies, yet reveal relative effects from 0.4% to 34.6%. This study is the first to methodically unpack the key determinants of grid EF, quantify their impacts, and offer clear guidelines for their application in corporate GHG accounting. Our findings hold implications for practitioners, data publishers, researchers, and guideline-making organizations. By openly sharing our data and calculations, we invite replication, scrutiny, and further research.