Solar PV projects generate carbon credits by displacing electricity that would otherwise have been generated by the grid, typically from fossil fuel sources. The credit yield is determined by how much electricity the solar installation generates and how carbon-intensive the displaced grid electricity is. This is one of the more straightforward credit calculation methodologies, but the grid emission factor is the single most important variable and varies significantly by country and year.
How solar credits are calculated
Annual generation (MWh)
Determined by installed capacity (kWp), the location-specific irradiance (usually expressed as peak sun hours per day), system efficiency losses (inverter, wiring, soiling, degradation), and panel tilt and orientation. Performance ratio typically ranges from 75 to 85 percent for well-maintained systems.
Grid emission factor (tCO2e/MWh)
The carbon intensity of the electricity displaced. This is set by the approved national or regional baseline, using either a combined margin (operating margin and build margin weighted average) or a simple average grid factor approved by the relevant methodology. Factors range from under 0.2 tCO2e/MWh in hydro-heavy grids (Norway, Brazil) to over 0.8 tCO2e/MWh in coal-heavy grids (South Africa, India).
Own use and export split
Where the project serves both self-consumption and grid export, the methodology typically credits only the exported portion at the full grid factor. Self-consumption is credited at the avoided retail tariff emission factor, which may differ from the grid baseline.
Try the calculator
Use the full tool in The Carbon Workbench to save your calculation, model a full crediting period and pair with the feasibility and verification cost tools.
Open full Solar CalculatorGrid emission factors by region (2025)
| Region / grid | Approx. grid factor (tCO2e/MWh) | Notes |
|---|---|---|
| UK (National Grid) | 0.18-0.22 | Declining as coal exits; wind-heavy |
| India (national average) | 0.65-0.82 | High coal dependency; declining with RE build |
| South Africa | 0.78-0.92 | Eskom coal fleet; among highest globally |
| Germany | 0.35-0.45 | Mixed renewables and lignite |
| Brazil | 0.06-0.12 | Hydro-dominated; very low baseline |
| Kenya | 0.15-0.25 | Geothermal and hydro mix |
Which methodology applies?
The most common methodology routes for grid-connected solar PV are Gold Standard GS4GG (AMS-I.D for small-scale) and Verra VCS ACM0002 or AMS-I.D. The choice depends primarily on project scale, target buyer and whether SDG co-benefits will be claimed. Use the Methodology Selector to get a recommendation based on your project specifics.