Grid carbon intensity is the amount of greenhouse gas emissions associated with generating one unit of electricity delivered by the grid, typically expressed as gCO₂e per kWh. It reflects how “clean” or “carbon-heavy” electricity is at a given time and location, based on the mix of generation sources supplying the grid.
What Is Grid Carbon Intensity?
Grid carbon intensity measures emissions per unit of electricity.
– Usually reported as gCO₂e/kWh (grams of CO₂ equivalent per kilowatt-hour)
– Can be calculated at the national, regional, or even real-time system level
– Changes over time depending on generation mix, imports/exports, and demand
Why Grid Carbon Intensity Matters for EV Charging
Grid carbon intensity directly affects the reported emissions of EV charging and electrification.
– Determines charging-related emissions in location-based carbon accounting
– Influences CO₂ savings reporting and “gCO₂ avoided per session” calculations
– Helps optimize charging to lower-emission periods using carbon-aware charging
– Supports credible sustainability claims for charging operators and fleets
– Impacts product and operational carbon footprint calculations for ESG reporting
Types of Carbon Intensity Values
Grid carbon intensity can be represented in different ways depending on the reporting method.
Average carbon intensity
– Uses average emissions per kWh over a defined period (annual, monthly)
– Common for corporate reporting and simplified calculations
– Less accurate for time-shifted optimization because it smooths the variation
Marginal carbon intensity
– Estimates the emissions impact of an incremental change in demand
– More relevant for assessing the emissions effect of shifting charging in time
– Can differ significantly from average intensity during certain periods
Location-based vs Market-based Reporting
Grid carbon intensity is used differently depending on the carbon accounting method.
– Location-based: uses grid average intensity for the region where consumption occurs
– Market-based: uses supplier-specific factors or renewable certificates (GOs/RECs) depending on procurement approach
A clear methodology definition is essential to avoid inconsistent reporting.
What Affects Grid Carbon Intensity
– Share of renewables (wind, solar, hydro) vs fossil generation
– Fuel mix (coal vs gas) and plant efficiency
– Imports/exports and cross-border flows
– Demand level and dispatch order (what plants are marginal)
– Weather patterns and seasonal variation
– Grid congestion and local constraints
How Grid Carbon Intensity Is Used in Charging Analytics
– Emissions per session: kWh delivered × gCO₂e/kWh
– Carbon-aware scheduling: shift charging to lower-intensity periods
– Portfolio reporting: total delivered kWh × average intensity
– Comparing sites and regions for sustainability strategy and investment planning
Common Pitfalls
– Mixing location-based and market-based methods in the same KPI without stating it
– Using annual average factors for real-time carbon-aware claims
– Claiming “zero-emission charging” without defining certificate treatment and boundaries
– Ignoring losses and measurement boundary (metered at charger vs delivered to battery)
Related Glossary Terms
Carbon intensity
Carbon-aware charging
Market-based emissions
Location-based emissions
Green energy certificates
Guarantees of Origin (GO)
CO₂ savings reporting
gCO₂ avoided per session