E-bikes: a carbon efficient mobility solution

This article was written by François Chaté for Vectos, part of SLR. Vectos specialise in transport planning, mobility solutions, infrastructure design, microsimulation and flood risk.

To combat the Climate Emergency we’re facing, mobility is becoming electrified. EVs and e-bikes are getting more and more popular and are seen as a big part of the solution to achieving net zero targets. But have you ever wondered what these actually cost in terms of carbon emissions?

Back in June 2019, the UK passed legislation setting itself a legally binding target to achieving net zero carbon emissions by 2050. As a result, a wide range of strategies are being identified and progressed by the UK Government, including the Transport Decarbonisation Plan as detailed in ‘Decarbonising Transport: A Better, Greener Britain’ (DfT, 2020). The Plan includes a wide range of commitments and initiatives aimed at reducing carbon emissions from transport.

The task is extremely challenging, but equally urgent. Transport is the largest contributor to UK domestic greenhouse gas (GHG) emissions, responsible for 27% of emissions in 2019. The total domestic transport emission of GHG was calculated to represent 122MtCO2e in 2019. Unsurprisingly, the main GHG emissions culprits are ‘cars and taxis’ (68MtCO2e, 56%, in 2019). The least polluting modes are of course active modes (walking and cycling) and electric vehicles (EVs). The Transport Decarbonisation Plan puts the onus on modal shift, placemaking, and facilitating the take up of EVs, amongst other strategies aiming at reducing emissions across the entire transport sector ( freight, air travel, rail travel etc).

Although EVs have a significant role to play in achieving reduced emissions at the ‘tail pipe’, I have wondered how environmentally friendly it would actually be to accelerate the renewal of the UK vehicle fleet. Interestingly, ‘Decarbonising Transport: Setting the Challenge’ (DfT, 2020), the ‘prequel’ to the latest Transport Decarbonisation Plan, indicates that the set transport related commitments and strategies relate to tackling carbon emissions ‘in use’, not from manufacturing new vehicles. However, when addressing the Climate Emergency, surely one cannot just ‘pick and choose’ the elements that are considered when assessing emissions and a holistic approach is required.

It was interesting to come across the The Role of E-Bikes in Decarbonising Transportation article setting out a comparison of EVs and e-bikes in terms of carbon cost. This article indicates that the carbon cost of manufacturing a bike is around 100kgCO2e and for an e-bike around 150kgCO2e. In contrast, the carbon cost of manufacturing a small hatchback car is 5.5tCO2e, and a SUV 13tCO2e. Some estimate that the carbon cost of manufacturing an EV is up to 68% higher than manufacturing the equivalent ICE vehicle, so for a long-range electric SUV, it would be around 22tCO2e! Of course, an EV would fair better with use, but the article also provides a comparison by km travelled. The carbon cost of a bike is estimated at 25-35gCO2e per km, and an e-bike 21-25gCO2e per km. The carbon cost of an EV is estimated at 160gCO2e per km.

The carbon cost differences between bikes/e-bikes and cars/EVs are so significant, that we must realise that EVs are not the panacea when it comes to carbon reduction.

My view is that as professionals in development planning, we must work towards delivering a shift from cars/EVs to active modes of travel, with cycling either on a bike or e-bike being the most important alternative to help address the Climate Emergency. An EV is still a car. They will still ‘clog up’ roads, demand a disproportionate amount of space, with the resulting negative impact on sense of place, severance, wellbeing and mental health.

‘Decarbonising Transport: A Better, Greener Britain’ indicates that 58% of journeys less than 5 miles are made by car. E-bikes provide an excellent alternative for these shorter trips, and the Plan estimates a potential reduction in emissions of 68MtCO2e if we were to substitute those trips.

The need to deliver a modal shift away from the car to active modes, in particular cycling, is still the most important part of our work, it is simply becoming ‘electrified’ with a shift from EVs to e-bikes. If carbon emission is adopted as the Key Performance Indicator, the case is clear. This shift needs to occur.

But, using carbon emission as a Key Performance Indicator in transport and town planning decision making is probably a topic for another blog…