The CO2 Footprint of Ebikes vs. That of Cars

Most people seem to have accepted that climate change is caused primarily by burning fossil fuels. The debate is now switching to the carbon footprint of new technologies that are slowly replacing the present fuel-burning ones.

Updated on 08.24.2023

A somewhat cheesy topic?

Probably, not many could  fathom the appalling death toll of tiny particulates emitted by exhaust pipes  (p.m. 10 & 2.5). Its “just” more than eight millions individuals per year worldwide, according to a recent study by the Harvard University. Sometimes these estimations vary from one source to another, depending on their political orientation, who is directly (or indirectly via advertising) financing their publications, and so on. The Harvard University has a good reputation, anyway.

Transportation is essential to economic, social and even cultural development. Yet, not only it pollutes the air, but does it near our noses, unlike pollution from power plants and industries. Could a widespread usage of bikes and e-bikes a solution? Would it improve air quality and promote a healthier lifestyle?

The CO2 footprint of cars production vs. that of Ebikes

Calculating the carbon footprint of producing a car with a decent approximation, not to mention precision, is a hard task. One should take into account lots of conditions changing with space and time. Here is a non-exhaustive list of the sources of CO2 that car production can emit:

1. electricity and fuel for the extraction of iron ore, copper, silver, platinum, palladium, bauxite and other minerals
2. electricity and fuel for the production of plastic
3. electricity to produce and assemble the car parts
4. electricity for the functioning of offices
5. fuel to carry the workers to car plants and to offices
6. fuel for the transportation of the car parts and materials to the final assembly line
7. fuel for the transportation of the car from the assembly line to the final purchaser

Here’s what The Guardian reckons for The carbon footprint of a new car:

• 6 tonnes CO2e: Citroen C1, basic spec
• 17 tonnes CO2e: Ford Mondeo, medium spec
• 35 tonnes CO2e: Land Rover Discovery, top of the range

For an e-bike, the most energy consuming part is the battery

A 2019 paper from the IVL Swedish Environmental Research Institute (source: Forbes) reviewed the available carbon emissions data for lithium-ion batteries. The authors found that the production of the upstream battery materials generally accounts for the largest share of the emissions, which they identified as 59 kilograms (kg) of CO2 equivalent (eq) per kilowatt-hour (kWh) of battery capacity. The cell production and battery pack assembly consume more electricity, so this process is highly dependent on the type of electricity used. For this process, the authors estimated a range of 0-60 kg CO2-eq/kWh battery, going from 100% renewable power, up to primarily power derived from fossil fuels. The total amount can go from 59 to 129 Kg per kWh battery.

The calculation is all the more complicated, since the most fluctuating variable is the source of electricity. Indeed a country like France produces only 1/10 of its electric energy using fossil fuels, whereas countries like China or Australia produce at least 50% of their Kwh burning coal or gas. Then you have countries like Portugal and Germany, which, in a sunny or windy day, can fulfill the whole of their electric energy needs with renewables, still needing to burn fossil fuels whenever wind and sun are lacking. Therefore, a battery produced in a windy day in Germany has a carbon footprint considerably lower than the same battery produced when the wind is still.

Regarding production, let me boil it down to a few digits

Assuming that energy consumption is roughly the same for each kg of vehicle manufactured, an electric bike weighs, on average, excluding the battery, 21 kg, vs. 1,700 kg for a car, i.e. 81 times more. We can take into account that some bikes are made of aluminum, which needs more energy than steel, and the energy needed to produce the battery. The latter amounts to roughly 30 Kg of Co2 for a 500 Wh battery, following the above-mentioned criterion, giving a total of  51 kg of Co2. Even then, we could reckon that producing a car generates at least 33 times more CO2 than producing an ebike.

Recycling

Once again, advantage for e-bikes: they contain very little plastic, unlike cars, and Li-ion batteries are 95 % recyclable (in Europe by Bosch, Renault, Veolia to quote just a few).

For cars, the percentage of recycling is an average 85% in the E.U., if we are to believe the European Commission: End-of-life vehicle statistics – Statistics Explained (europa.eu)

Between driving and riding, the gap is even wider: 100 times less CO2!

Driving a car produces, on average, at least 130 g of CO2 per kilometer, 11.5 tons for 78,000 km with a Renault Scénic, according to Car carbon footprint calculator. An E-bike can be ridden for at least 100 km with a Kwh of electricity, since a 500 Wh battery provides a range of at least 50 km. Thus, even if those Kwh were to be produced burning exclusively fossil fuels, we can approximately estimate the consequent CO2 production between 1 and 2 g per kilometer.

Electric bikes are cool, wheareas cars are driving heaters

A 2,000 cc car engine spits into the atmosphere two liters of hot gases (400 C° or 752 F) for every tour. At an average 3,000 tours per minute, that is tantamount to 180,000 liters, or 180 cubic meters, of hot carbon dioxide, hot water vapour and hot  toxic gases (carbon monoxide, unburned hydrocarbons, irritating and carcinogenic, nitrogen oxides, nitrogen) per hour of driving. What effect do you reckon it can have on global warming?

Let me put it bluntly

Why worrying about the little CO₂ deriving from battery manufacturing, when gas guzzling transport spits far more than a kilogram of CO₂ and poisonous gases every 10 km, right below our noses? Jeopardizing our whole planet, whilst e-cars and e-trucks are yet not affordable for the masses. For instance, DHL, probably the world’s largest shipping and delivery company, recently bought several types of cargo e-bikes, just Google “DHL cargo e-bikes”. They reckoned that they are by far cleaner than internal combustion vehicles, regardless of the CO₂ ejected for their manufacturing. Hence, if you feel proud of riding your e-bike to work, well, you may not be that wrong, no matter how it was produced!