Emissions factors in the different emissions reports

In Ekotrope v4.2.0 support was added for the HERS Carbon Rating Index, this also involved a major update to the emission factors to comply with MINHERS Addendum 66f.

For electricity use, Addendum 66f, requires the calculation of emissions to use region based annual rates for NO_x and SO₂ published by the Environmental Protection Agency’s 2020 eGRID database, but for CO₂e emissions hourly rates are derived from the 2021 Cambium database in the Cambium Grid and Emission Assessment (GEA) regions. The CO₂e emissions combine CO₂, CH₄, and N₂O and do not include NO_x and SO₂.

The emission reports will now use different factors depending on except for the Carbon Index Emissions Comparison is always calculated in accordance with MINHERS Addendum 66f regardless of version. To summarize:

• The Carbon Index Emissions Comparison always use the annual SO₂ and NO_x factors from the 2020 eGRID dataset, and hourly CO₂e emission factors from the 2021 Cambium dataset.
• In versions prior to Version 4.2.0 other emissions reports use older emissions factors for CO₂, SO₂, and NO_x from an older eGRID dataset.
• In Version 4.2.0 and beyond all emission reports use the annual SO₂ and NO_x factors from the 2020 eGRID dataset, and hourly CO₂e emission factors from the 2021 Cambium dataset.

For fossil fuels sperate emissions factors for CO₂, SO₂, and NO_x are taken from constants published in MINHERS, which were also updated in MINHERS 66f Table 5.1.2(1). The Carbon Index Emissions Comparison will always use the updated rates published in MINHERS 66f. For emissions reports using in version prior to v4.2.0 the fossil fuel emissions rates are unchanged, but for reports in Version 4.2.0 and beyond all emission reports are using updated rates published in MINHERS 66f.