SIMAP now has 4 versions of emission factors available for use:
- 2022 version (recommended)
- 2021 version (outdated)
- 2020 version (outdated)
- 2019 version (outdated)
- 2018 version (outdated)
- 2017 version (outdated)
Which version should you use for your current and historic calculations?
The recommended practice is to use the current recommended emission factor version (2022 version) for ALL years of your footprint calculation. Every version of emission factors extends back to 1990 in SIMAP. Historic emission factors can change in new emission factor versions for two reasons:
- New data sets become available. For example, there is usually a 2-year lag time in when eGrid releases the purchased electricity emission factors. This means until earlier this year, we had been using 2019 eGrid emission factors for 2020 and all subsequent years. eGrid just released the 2020 emission factors earlier this year, so that means that your calculated footprints for 2020 and 2021 will change a little bit with these new and more accurate emission factors.
- New methodologies are recommended. This happens when a new methodology becomes available that does a better job of estimating emissions.
In general, this is an important reminder that footprint results are always estimates based on the best available data at the time. As our understanding improves and as new data sets become available, we are able to refine our current and historic results. Select your emissions factor version on the calculation sources and methods form.