EC Enterprise: Why doesn't the eGRID GHG emission factor(s) assigned to my electric meters in EnergyCAP correspond to the eGRID emission factor assigned in Energy Star's Portfolio Manager?
Posted by Matthew Heinz, Last modified by Joel Brickell on 24 May 2021 08:35 AM
Problem/Issue: Why doesn't the eGRID GHG emission factor(s) assigned to my electric meters in EnergyCAP correspond to the eGRID emission factor assigned in Portfolio Manager?
The GHG emission factors found in both EnergyCAP and Portfolio Manager are from the same source, eGRID. However, there are a couple of potential reasons that your emission factors do not match what you see in Portfolio Manager:
Potential Reason for discrepancy #1:
Currently the EnergyCAP electricity GHG emission factors come from the eGRID state aggregation tables, whereas the emission factors in Portfolio Manager are obtained from the eGRID subregion aggregation tables. There can be discrepancies between the two methods of aggregation dependent upon the amount of electricity imported by a state in order to meet consumption needs. For cases where a state imports a significant portion of electricity the state aggregation emission factor will be less than that of the corresponding eGRID subregion.
Solution for discrepancy #1:
Download the latest eGRID subregion emission factors from the EPA's eGRID website and utilize the EnergyCAP functionality to create desired subregion GHG emission factors in your database. Detailed instructions for creating user specific GHG emission factors can be found in the user manual (User-Create GHG emission factors).
Once the subregion emission factor(s) have been created in EnergyCAP it is necessary to assign/link the emission factor(s) to the desired meter(s) and run the GHG processor to recalculated the GHG emissions. Instructions for assigning reporting scope, emission factors, and running the GHG processor can be found in the user manual (Setting the Default GHG Reporting Scope and Emission Factor).
Potential Reason for discrepancy #2:
The latest eGRID emission factors have not been imported into your EnergyCAP database. Typically the EPA releases new eGRID data on a bi-annual basis, the most recent being the eGRID 2010, for 2007 emission data, originally released in February of 2011.
Solution for discrepancy #2:
Visit the EPA's eGRID website to determine the latest version of the eGRID data that is available from the EPA. Next you will want to check the Source for the existing eGRID GHG emission factors that are loaded in your EnergyCAP database. Locate an electric meter in EnergyCAP that you are sure has GHG factors assigned and view the emission factor details.
Note the source of the most recent factor assigned, if it does not correspond to the latest eGRID data available from the EPA then you will need to download the latest GHG XML file from the EnergyCAP showdownloads site. Use the login credentials that were provided in Appendix A of the EnergyCAP release 6.2 upgrade installation instructions by customer service. If you are unable to find the original email containing the upgrade installation instruction from customer service, please contact our customer support team for assistance with downloading the latest emission factors. Once the latest GHG XML file has been imported into your EnergyCAP database you will need to run the GHG processor for all meters in order to apply the newly imported/updated GHG emission factors.
Created by Scott Bair 06/2/2011 Updated by Matthew Heinz 07/01/2011