The current phase of sustainability in transportation is about making cars electric.

It seems like we have done quite well already, with Tesla trading as the most valuable car company and other EV startups like Rivian, Nio, Faraday Future, and others raising billions of dollars from investors. Even some traditional OEMs are announcing electrification plans with an aggressiveness that was considered unthinkable a decade ago. 

Critics of electric cars will point to the fact that they aren’t actually very sustainable because the manufacturing of batteries is very carbon intensive and  charging an electric car still uses energy generated with non-renewable sources. This is false in all but the most extreme cases with an average electric car in the US producing approximately 1/2 the carbon as a gasoline equivalent and slightly less in Europe [1]. But even with the carbon reduction of EVs, we are still falling behind our timeline for keeping global warming less than 2 degrees Celsius [2]. The recent benefits from electric cars have been largely cancelled by the increase in carbon from transportation due to the upsizing of cars and increase in travel [3]. The manufacturing of any electric vehicle still produces significant amounts of carbon and it will take decades before the energy used to charge electric vehicles around the globe will be even 50% renewable [4].

There is nothing that is more effective currently at reducing carbon from vehicle manufacturing and use than simply making the vehicles smaller and lighter. Smaller and less weight means less materials to process when manufacturing the vehicle. It means less batteries is needed to reach the same range as a heavier vehicle. It means less energy to accelerate and maintain speed because of reduced rolling resistance and aerodynamic drag (I designed and helped build a vehicle that achieved 1496MPG with a gasoline motor simply by making it very light and aerodynamic, enough to become the second most fuel efficient in North America at the time). Even public transit like buses and trains, which practically do not have full capacity all the time, cannot compete in terms of energy efficiency with small and light vehicles.

Data sources: Deutsche Bahn, Alternative Fuels Data Center, Harvard

Nimbus's vehicles weigh around 300kg, 6x less than a Nissan Leaf. Our estimated efficiency is 370MPGe, 3x better than the Nissan Leaf. We think we can improve on efficiency even more in the future by optimizing things like aerodynamics and tires. The lifetime carbon emissions including those generated during production and use we estimate to be 3-4x less than a Nissan Leaf based on a much lower vehicle weight. We also plan on using a powder coated frame and plastic body panels, which reduces VOCc from the traditional car painting process.  

One reason for the slow adoption of EVs is the price. It will take several more years before EVs can reach price parity without large incentives [5]. It will likely take another 20 years before electric car sales have reached over half of all car sales around the world [6]. By this point, electric cars will still only represent 1/3 of all cars on the road [6]. People are owning their cars longer and longer before buying another one. There are 1.4 billion automobiles on the road today, 98% of which are petrol. These vehicle will go on to emit carbon for on average 5 years before being replaced by more, mostly gasoline powered vehicles. We can't afford to wait for everyone to switch to electric cars in a climate crisis.

Projected Global Light-Duty Vehicle Fleet (Source: Bloomberg New Energy Finance)

One shortcut to the long replacement cycle of automobiles is to offer a supplemental option that can co-exist with an owned car but can replace a portion of trips, sort of like a bike on steroids. As we’ve seen with the rapid adoption of shared electric scooters, people will enthusiastically use alternative transportation methods that are much more minimal than the cars that they purchase. The average American spends $165/month just on gasoline with more than half of the miles driven covering trips under 15 miles, and about 40% of those under 6 miles. Americans spend another $150/month or more just on parking in the largest cities [7]. By offering a rental for under $150 a month, I believe it will encourage many people to leave their cars home for their everyday trips. It would be like the equivalent of moving to Amsterdam with a car but leaving it at home most days of the week because biking is cheaper, faster, and safe by using their bike paths. Not every city can be Amsterdam but we can make the short-to-medium distance vehicle for every city.

E-bikes have the capability to extend the range of how far people are willing to travel on bikes and have seen a steady growth recently. There are two reasons I don't believe they'll replace a significant portion of car trips. One, I just don't think most people want to pedal every time they have to go somewhere, and two, there isn't enough bike lanes in most places to allow bikers to travel safely for long distances. Even in the Netherlands, which has one of the strongest bike cultures in the world with cities like Amsterdam that actually have policies and roads that put cars at a disadvantage, 77% of commute kilometers are still covered by car, and just 6% by bicycle. There are reasons why the car is so popular and I think we should try to give people most of what they like about cars.

We plan to eventually offer even shorter rental periods, down to the minute. Existing renters who have already paid for longer periods can sub-rent their vehicles and reduce their monthly costs even more. Hourly car share programs like Zipcar and Car2Go have bad unit economics because even the smallest Smart car has high depreciation, insurance, and running costs. A smaller electric vehicle does the job of a Smart car better and for less cost in a city vehicle share. Vehicle sharing not only reduces the cost for each person using it compared to having one to themselves 24/7, but it also reduces the environmental impact during manufacturing. 

I believe the next phase of sustainable transportation will not just be electric vehicles but a shift towards smaller and lighter vehicles, with a substantial of them being shared. Besides the well known electric scooters and bikes that have taken over many cities, there also has been recent activity in shared miniature cars in Europe [8][9]. I believe the environmental benefit is at least on par with, if not better than switching to from gasoline to electric cars.

I’m glad electric cars have become cool and are becoming mainstream, but with transportation recently becoming the number one contributor of carbon in the US, it’s not enough to meet our goals to slow down climate change. It’s time we break the cycle of bigger and more cars. 


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