This graph by @VWGroup is doing the rounds suggesting it takes 120 000 km before the new Golf emits less CO2. But that's wrong. The correct number is less than 20 000 km. Let me show you.
First the diesel use of the regular golf. According to spritmonitor.de that's around 5.8 l/100 km (spritmonitor.de/de/uebersicht/…).
Multiply that by 3310 gram/l () and you get 190 g/km.
Multiply that by 3310 gram/l () and you get 190 g/km.
But wait: the graph shows the emissions over 200 k km increasing from 6 to 28 tonnes. That's 22 tonnes for 200 k km or 110 g/km! That is MUCH less than in reality!
What went wrong here? Probably a combination of taking the unrealistic NEDC and forgetting diesel production.
What went wrong here? Probably a combination of taking the unrealistic NEDC and forgetting diesel production.
But it gets worse! Producing the EV emits 12 tCO2 and the normal golf 6 tCO2. If we assume 1tCO2 extra for the conventional drivetrain compared to the electric drivetrain that means 7 tCO2 for the battery. And that battery is just 35.8 kWh. So that's 195 kg/kWh.
That is ludicrous. Modern sources put it at below 100 kg/kWh and I use 65 kg/kWh.
sciencedirect.com/science/articl…
Even the outlier study from Romare has now been updated to below 100 kg/kWh.
sciencedirect.com/science/articl…
Even the outlier study from Romare has now been updated to below 100 kg/kWh.
Let's use 100 kg/kWh and we get 3.6 tCO2 for the battery. Let's subtract 1 tCO2 for the simpler drivetrain.
The result is now that the eGolf only costs 2.6 tCO2 more to produce.
The result is now that the eGolf only costs 2.6 tCO2 more to produce.
So to summarize:
VW estimates its normal golf uses only 3.3 liter diesel per 100 km while in reality it is 5.8 l/100 km.
VW exaggerates the carbon footprint of battery production by a factor of two.
If you correct for those two errors the graph looks like this.
Go figure.
VW estimates its normal golf uses only 3.3 liter diesel per 100 km while in reality it is 5.8 l/100 km.
VW exaggerates the carbon footprint of battery production by a factor of two.
If you correct for those two errors the graph looks like this.
Go figure.
Forgot to add the usual caveat: until we mine, manufacture and drive on low carbon energy, EVERY car emits a lot of CO2.
So biking, car sharing and public transportation (esp. electric) are still better for the planet.
But, let's not make the perfect the enemy of the good.
So biking, car sharing and public transportation (esp. electric) are still better for the planet.
But, let's not make the perfect the enemy of the good.
