The CO₂ savings are calculated based on the amount of energy (kWh) that employees with a company car charge. We convert those kWh into the number of kilometers an electric car can typically drive, and then compare the CO₂ emissions of those kilometers with those of a conventional gasoline or diesel car.
Formula
CO₂ savings = charged kWh × savings (kg/kWh)
Where Savings (kg/kWh) = 0.718 kg CO2
This is the difference between the average emissions of an internal combustion engine (ICE) vehicle and the emissions associated with electricity production.
=> Every charged kWh in an electric vehicle saves on average 0.718 kg CO₂ compared to driving a gasoline or diesel car.
Calculation example:
133,780 kWh x 0.718 kg/kWh = 96,054 kg
Calculation of savings kg/kWh
Step 1: Emissions of internal combustion engine (ICE) vehicles
Based on official consumption values and emission factors, we calculate the average emissions per kilometer of gasoline and diesel cars in Belgium.
- Average gasoline emissions: 160.3 g/km
- Average diesel emissions: 186.5 g/km
- Fleet distribution: 61.8% gasoline, 38.2% diesel
➡️ Average ICE emissions = 0.1703 kg CO₂/km
Step 2: Efficiency of electric vehicles
An electric vehicle drives on average 4.99 km per kWh. This corresponds to a consumption of 20.04 kWh per 100 km.
Step 3: Emissions from electricity production
The CO₂ emissions from electricity production in Belgium averaged 0.1317 kg CO₂/kWh in 2024 (residual mix).
➡️ Converted to an electric vehicle: 0.0264 kg CO₂/km (= (20,04 kWh/100km * 0,1317 kg CO₂/kWh) / 100 km)
Step 4: Net CO₂ savings
- ICE car: 0.1703 kg CO₂/km
- EV: 0.0264 kg CO₂/km
➡️ Savings per km: 0.1439 kg CO₂/km
Because an electric vehicle drives on average 4.99 km per kWh, this corresponds to:
➡️ 0.718 kg CO₂ savings per kWh charged
Sources
- Consumption and average emissions of gasoline and diesel cars: GHC protocol, emission factors 09/2024
- Ratio of gasoline and diesel cars in Belgium: Statbel (2024)
- EV consumption data: VAB, Average BEV consumption (2019–2025)
- Electricity production emissions Belgium: Engie, official residual mix 2024