Canary Media published a state-by-state map of electricity carbon intensity on 25 September 2026, built on 2024 federal data compiled by the Institute for Progress. Vermont ranks cleanest. West Virginia, Kentucky and Wyoming rank dirtiest. It is a useful picture of where power is generated. It is the wrong input for Scope 2 emission factors.
Location-based Scope 2 inventories in the US typically use the Environmental Protection Agency (EPA) Emissions and Generation Resource Integrated Database (eGRID), which reports factors by grid subregion, not by state. For a company with sites in New York City, upstate New York and Boston, the gap between the two approaches is large enough to move a corporate total.
State generation figures understate New York City sites by 46%
eGRID2023, the latest EPA edition (revision 2, released 12 June 2025), gives a total output rate of 865.7 lb carbon dioxide equivalent (CO2e) per megawatt-hour (MWh) for the NYC/Westchester subregion (NYCW). New York State’s generation rate in the same dataset is 466.6 lb CO2e/MWh. Upstate New York (NYUP) is 242.8 and Long Island (NYLI) is 1,189.3.
The state figure blends upstate hydro and nuclear output with the in-city plants that serve New York City. Apply it to a Manhattan office and the inventory understates that site by 46%.
The same load produces very different footprints
We calculated the location-based Scope 2 emissions of a site using 1,000,000 kWh of grid electricity a year. Method: kWh divided by 1,000, multiplied by the eGRID2023 rate in lb CO2e/MWh, divided by 2,204.62 lb per metric ton.
- NYC/Westchester (NYCW): 392.7 tCO2e
- Long Island (NYLI): 539.5 tCO2e
- Upstate New York (NYUP): 110.1 tCO2e
- New England (NEWE), including Boston: 246.4 tCO2e
- US average: 349.7 tCO2e
- New York State generation rate, for comparison: 211.6 tCO2e
A Manhattan site emits 3.6 times more per kWh than the same load upstate. Portfolio decisions built on a single state number miss that spread.
Massachusetts shows the reverse error
Massachusetts’ state generation rate is 830.1 lb CO2e/MWh. The New England subregion rate is 543.2. Boston sites draw from the regional ISO New England grid, which eGRID treats as one subregion. A Boston site inventoried on the state figure would be overstated by 53%.
Scope 2 emission factors must be consistent across every site
Mixing sources across sites breaks year-on-year comparisons and invites assurance findings. European subsidiaries reporting under the Corporate Sustainability Reporting Directive (CSRD) disclose both location-based and market-based Scope 2, so the US group inventory needs to reconcile to the same method.
Three checks for your next inventory:
- Map every US meter to its eGRID subregion by ZIP code, not by state.
- Record the eGRID edition and revision used, and update it once per reporting cycle.
- Report market-based Scope 2 separately where you hold supply contracts or renewable energy certificates.
A clean baseline makes every reduction count
Grid factors also shape the case for electrification. A heat pump on the NYCW grid today carries a higher emissions factor per kWh than the same unit in New England, which changes the emissions payback. Climeaction builds Scope 1, 2 and 3 footprints site by site, with the factor source documented for auditors.
See our advisory and reporting service, test a site with the carbon calculator, or contact us to review your inventory.
State generation maps show where power is made, not the factor a site should report. Using eGRID subregions keeps New York City and Boston sites accurate and comparable year on year.
