Calculate market-based Scope 2 emissions with REC matching per GHG Protocol

Verified steps

1. Determine which GHG Protocol Scope 2 Guidance version governs the reporting period; as of 2026, the GHG Protocol is in public consultation on proposed revisions requiring hourly matching and deliverability — confirm whether annual or hourly matching applies to your reporting obligation.
2. Obtain Energy Attribute Certificates (EACs) — RECs in North America, GOs in Europe — that cover the reporting period; record for each EAC: certificate serial number, generator name, fuel type, generation period (month and year, or hour for hourly matching), generating region/balancing area, and registry of issuance.
3. Match EACs to consumption: under the current annual method, total EAC MWh must be >= total consumed MWh in the same market boundary (country or sub-national region as defined by the GHG Protocol); under the proposed hourly method, match EAC generation hour to consumption hour within the same grid region.
4. For unmatched consumption (hours or quantities not covered by EACs), apply the residual mix emission factor for the relevant market, not the grid average — residual mix factors are published annually by bodies such as the Association of Issuing Bodies (AIB) for Europe or estimated by tools like EPA eGRID for US markets.
5. Calculate market-based Scope 2 emissions: sum (unmatched_MWh * residual_mix_factor_tCO2e/MWh) across all unmatched periods; matched consumption covered by EACs from zero-carbon generators contributes zero to market-based emissions.
6. Report both location-based and market-based Scope 2 figures as required by the GHG Protocol dual reporting requirement; document EAC serial numbers, matching methodology, and residual mix factor sources in the supporting disclosure.