Charging an electric vehicle still uses electricity, and in India much of that still comes from coal. So the honest question is not "how much CO2 does an EV save" in general, but how much your chargers help avoid compared with the petrol or diesel the same kilometres would otherwise have used.
What you need
- Energy delivered by the charger (kWh), from your management system.
- Vehicle efficiency: kilometres per kWh for the EVs that charge, or a reasonable average.
- Comparison vehicle: the fuel economy of the petrol or diesel vehicle it replaces.
- Emission factors: for grid electricity and for the fuel.
Emission factors
- Grid electricity: the Central Electricity Authority's CO2 Baseline Database gives a weighted average of 0.727 tonnes of CO2 per MWh (0.727 kg per kWh) for FY 2023-24 (version 20.0).
- Petrol: a commonly used figure is about 2.3 kg of CO2 for each litre burned.
- On-site solar or verified renewable power: close to zero at the point of use.
The calculation
- EV emissions: kWh delivered × grid factor.
- Kilometres powered: kWh delivered × km per kWh.
- Fuel avoided: kilometres ÷ the comparison vehicle's km per litre.
- Fuel emissions avoided: litres × fuel factor.
- Net saving: fuel emissions avoided − EV emissions.
A worked example
Assume a charger delivers 10,000 kWh in a year, cars cover 7 km per kWh, and the petrol cars they replace do 15 km per litre.
- EV emissions: 10,000 × 0.727 = about 7,270 kg CO2.
- Kilometres: 10,000 × 7 = 70,000 km.
- Petrol avoided: 70,000 ÷ 15 = about 4,667 litres.
- Petrol emissions: 4,667 × 2.3 = about 10,730 kg CO2.
- Net saving: about 3,460 kg, or roughly 3.5 tonnes of CO2 a year.
This example uses illustrative assumptions. Replace them with your own data. Results change with vehicle type, driving conditions and the share of renewable power.
How to increase the saving
- Use renewable power: with on-site solar or renewable supply, the EV side of the sum falls towards zero. See green charging.
- Raise utilisation: more kWh delivered means more fuel replaced. See utilisation.
- Serve high-mileage vehicles: cabs, delivery fleets and buses replace far more fuel per charger.
- Grid improvement: as India adds renewable capacity, the grid factor should fall and savings rise.
EVee Buddy can produce yearly energy and estimated CO2 reports for each site, using your chosen assumptions.
Sources
Figures and rules change. Check the latest version of each source before using these numbers in official reporting.