Purchased electricity is reported two ways at once under the GHG Protocol Scope 2 Guidance: the location-based method uses the average grid factor for where you consume power, while the market-based method reflects the contractual instruments you buy — RECs, GOs, REGOs, I-RECs or a PPA. Enter consumption, pick a grid, choose an instrument, and see both numbers side by side.
market = covered share × 0 + uncovered share × residual mix. Buying high-quality EACs or a
PPA drives the market-based number toward zero but leaves the location-based number
unchanged. Grid and residual-mix factors here are illustrative; the live tool reads live factors from
the Master Brain data layer (IEA / Ember location factors, AIB & EPA residual mixes) and applies the
Scope 2 Quality Criteria to each instrument.
The methodology, standards, definitions and related tools behind this calculator — all live on the platform.