Hawaii outer islands (Maui, Kauai, Big Island) - oil-heavy with growing renewables. This page provides the official EPA eGRID2023 electricity emission factors for the HIMS subregion, used for GHG Protocol Scope 2 location-based emissions reporting.
The HIMS subregion is 47% dirtier than the US average (770.9 lb CO2e/MWh).
| Pollutant | lb / MWh | kg / kWh | Scope |
|---|---|---|---|
| CO2e (total GHG) | 1133.294 | 0.5141 | Scope 2 |
| CO2 | 1123.371 | 0.5096 | Scope 2 |
| CH4 (methane) | 0.146 | 0.00006622 | Scope 2 |
| N2O (nitrous oxide) | 0.022 | 0.00000998 | Scope 2 |
| NOx | 7.565 | 0.00343143 | Air quality |
| SO2 | 4.489 | 0.00203618 | Air quality |
| CO2 non-baseload | 1596.385 | 0.7241 | Scope 2 (marginal) |
Using HIMS emission factor: 1133.294 lb CO2e/MWh = 0.5141 kg/kWh. Source: EPA eGRID2023.
These emission factors are from EPA eGRID2023 Rev2 (released June 2025), the official US government source for grid electricity emission rates. eGRID uses annual net generation and emissions data from all US power plants to calculate subregion-level output emission rates.
For GHG Protocol Scope 2 reporting, use the CO2e total output emission rate: 1133.294 lb/MWh or 0.5141 kg/kWh.
Primary utility: Hawaiian Electric Company
Query HIMS emission factors by ZIP code:
curl "https://emission-factors.com/api/lookup?zip=YOUR_ZIP"
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The HIMS eGRID2023 Scope 2 location-based emission factor is 1133.294 lb CO2e per MWh (0.5141 kg CO2e per kWh). This is the value to use in GHG Protocol location-based Scope 2 calculations for facilities in the Hawaii Miscellaneous subregion.
The HIMS (Hawaii Miscellaneous) eGRID subregion covers: HI. Hawaii outer islands (Maui, Kauai, Big Island) - oil-heavy with growing renewables.
Multiply kWh by 0.5141. Example: 50,000 kWh × 0.5141 = 25705 kg CO2e (25.70 tonnes).
Query any US ZIP code via API
33,616 ZIP codes · All 27 eGRID subregions · EPA eGRID2023 + 2024 preliminary
Read the API docs · Scope 2 guide