Any vehicle that uses energy as its source of propulsion but produces no exhaust gas or other pollutants is considered a zero-emissions vehicle. Hybrid and plugin hybrid vehicles still emit some tailpipe pollutants, unlike fully electric vehicles. These vehicle types produce a lot less pollution than combustion vehicles as they have no tailpipe emissions. CAKE bikes, being powered by electricity, result in zero-emission driving, per definition. However, emissions are created from production, charging and end-of-life phase.

Although driving electric is considered zero emissions, the overall carbon footprint is not zero. Zero-emissions driving refers only to the use phase of the vehicle. While electric vehicles do not have any tailpipe emissions, they do produce emissions from a life-cycle perspective. Even the electricity that is used to charge the batteries has a carbon footprint. In simple words, nothing is truly zero emissions. It comes down to how we draw the boundaries to define emissions.

Electricity production

To better understand the emissions for driving an electric vehicle, we need to understand the emissions for producing the electricity consumed to drive. Figure 1 shows the average global emissions to produce 1 kWh of electricity.

CAKE bikes consume 0.03 kWh to drive 1 km. This equals 0.4 g CO2e per km if charged with energy produced from wind and 31 g CO2e when charged with energy produced from coal. A regular diesel car driving the same distance emits 214 g CO2e / km (2).This is nearly 99.9% emissions savings. As we can see, driving electric is not completely zero, the best scenario today is 0,4 g CO2e per km.

As most of us would just plug into our regional/national grid to charge our electric vehicle, the emissions per km varies drastically from country to country. For example, Figure 2 shows the European map with insights on how the grid emission factor varies in different European countries.

Electric vehicles do push the extra mile towards zero-emissions driving. However, there are other alternatives to electric vehicles, reducing emissions from the driving phase. HVO100 is a renewable fuel often referred to as zero-emissions driving.

HVO100

Hydrotreated Vegetable Oil (HVO) is a bio-based liquid fuel originating from many kinds of vegetable oils, such as rapeseed, sunflower, soybean, and palm oil, as well as animal fats. HVO100 has up to 90% less carbon emission than fossil based diesel. However, there are differences in how the environmental impact studies are considered, thereby reducing the benefit to between 90-50%. There are big variations between markets and raw material sources used for production.

The composition of the Swedish market for HVO consists of 72% slaughterhouse waste, 10% palm oil and palm oil fatty acid distillate (PFAD), 12%crude pine oil and 6% rapeseed oil 6%. (3) The source and production method of HVO is not yet mandatory to be disclosed by the producers, further decreasing the transparency around the exact emission reduction. As an example based on the raw material source, HVO100 would have a carbon footprint (well-to-wheel) of 1100 g CO2e/l, if produced from slaughterhouse waste. (4)

To put this data into perspective of driving, a regular diesel car fuelled with HVO100 would emit 71 g CO2e / km. This is a big reduction compared to conventional diesel 214 gr CO2e / km, but significantly higher emissions than electric alternatives, in particular electric 2-wheelers. In addition to CO2 emissions, HVO100 also emits other pollutants like particles, soot and nitrous oxides, which causes cardiovascular diseases, lung cancer and respiratory problems and is one of the very reasons for banning diesel cars in city areas. (5) Based on the definition of zero-emission driving (no tailpipe emissions), HVO does not fit in.

While both electric and renewable fuels reduce emissions in the use phase, we need to look beyond driving. For any electric vehicle, part of emissions originate from the production phase, and therefore we need to look from a life-cycle perspective when we talk about zero emissions.

Life-cycle footprint

While electric vehicle drivers can remove tailpipe emissions, electric vehicle manufacturers need to travel the extra mile to reduce the production phase emissions, as it stands for 25-95% of the total carbon footprint for electric vehicles. (6) Depending on the source of electricity used to charge the vehicle, the production emissions vary drastically in proportion to the driving emissions. The emissions originate from material extraction, material processing, manufacturing and transportation throughout the supply chain. Today, a CAKE bike emits slightly above 1 ton of CO2e to be produced and an electric midsize electric car 10-15 tons CO2e. Ultimately, also the end of life phase will add a share of emissions, depending on how efficient we can reuse the materials. Looking from a life-cycle perspective, electric vehicles still create carbon emissions.

CAKE has started the journey to decarbonize the production phase. In our joint project together with Vattenfall; The Cleanest Dirt Bike Ever, we are investigating the potential to reinvent the complete supply chain for the CAKE Kalk electric off-road bike. Our aim is to reduce the manufacturing footprint from 1186 kg CO2e to an absolute minimum by 2025. Insights and solutions will be implemented into CAKE volume production and openly shared with our industry and beyond.

To understand the magnitude of 1186 kg CO2e for one CAKE bike, the CARBON CUBE was created. The CUBE is a transparent 8.6-meter box that contains the total amount of carbon emissions currently created in the production of one CAKE Kalk off-road motorcycle, filling a 637 cubic meter cube, several times bigger than the bike itself. By visualizing our production footprint, it is clear how big of a problem it is, literally.

Every part of the bike and every product produced has a carbon cube link, and we are on the journey to decrease ours, centimeter by centimeter by removing CO2 from the production chain. We hope to create an example of transparency and inspire more brands to disclose their production footprint. Thus, helping consumers make conscious choices and to put the full life-cycle perspective in the center of discussion of zero-emission driving.

Summary

Zero-emissions driving should be one that is truly zero. Based on the current technology of today, this is not possible. Yet.

Every option has hidden values and it is unfortunate that companies and policy makers do not talk about the hidden emissions.

Well, at CAKE we aim to show all emissions. All the numbers are out there, all hidden numbers behind zero-emissions driving. Today, CAKE stands at 0.4 g CO2e / km for the use phase. Including the full life cycle, the current CAKE emission per km is estimated to be 36 g CO2e. CAKE´s mission is to inspire the transition towards a zero-emission society, including all hidden emissions.

References

1 https://www.nrel.gov/docs/fy21osti/80580.pdf

2 Eriksson, M. and Ahlgren, S. (1970) LCAs of petrol and Diesel: A literature review, Rapport (Institutionen för energi och teknik, SLU). Available at: https://res.slu.se/id/publ/40431 (Accessed: December 19, 2022).

3 https://energimyndigheten.a-w2m.se/FolderContents.mvc/Download?ResourceId=203063

4 https://f3centre.se/app/uploads/f3-23-17_2019-04_K%C3%A4llm%C3%A9n-et-al_Rev_190508_FINAL.pdf

5 https://www.reuters.com/article/us-climate-biofuels-idUSBRE90601A20130107

6 https://www.transportenvironment.org/discover/how-clean-are-electric-cars/