Why Green Transportation is Not All About Electric Vehicles
With transportation estimated to account for 16% of the world’s carbon dioxide production it is no surprise that the goal of global ‘net zero’ emissions is forcing us to change the way we think about moving around. This is why we have seen many governments mandate the move to electric vehicles and a growing number of automotive manufacturers announce plans to stop making cars and trucks built around the internal combustion engine.
However, while the technology to deliver electric vehicles is evolving at speed there are some significant challenges ahead in terms of infrastructure, the source of energy and practicality. Everything that Elon Musk says about Bitcoins, for example, is also true when it comes to electric cars. Specifically, if the source of energy is renewable, the electric car can be considered to be eco-friendly. However, if the source of energy is not renewable, then the electric car is actually responsible for creating more CO2 than a hybrid vehicle when you consider the end-to-end power chain from generation, distribution and conversion to the vehicle battery, electric motor and tires.
Focus on the Goal, Not the Technology
With this in mind it is important that we always keep in mind the ‘bigger picture’. This means we must continue to look at alternatives that could help achieve the net zero goal rather than dictating specific technologies just because they are politically expedient or currently ‘fashionable’.
Take biofuel as an example. Laws to mandate annually increasing targets for the percentage of biofuel could pay dividends in terms of goals for annual reductions of CO2. Certainly there is a case that hybrid vehicles and biofuel represent a winning combination considering:
- The energy density of liquid fuel is much higher than the energy density of existing battery technology, which ensures a lower weight to transport energy ratio. Reducing moving masses is the first step to saving energy.
- The speed of supply (filling the fuel tank) is significantly better than the best charger.
- Because combustion engines can work perfectly with pure or high percentages of biofuels such as ethanol, biodiesel or biogas the time to carbon neutrality will be much shorter.
- Hybrid plug-in vehicles can work in electric mode in the city streets or in areas where localized emissions are a problem, while on highways the combustion engine allows ultra-high autonomy and speedy refuelling.
- There are combustion engines that are even more efficient than those used today (e.g. the opposed piston engine). These engines can deliver efficiencies above 60%, even before considering the possibility of additional energy recovery that can increase this figure to 80% (depending on usage). Such efficiencies are currently impossible for any electric solution.
- In my opinion, existing hybrid vehicles are more technically advanced than electric cars since they bring together the best of multiple technologies that have been developed over many years. And they can be evolved further since we are a long way from reaching the limit of these technologies.
- We are far from having studied enough and from having invested enough resources in eco-friendly ways to generate bio-fuel.
Problems With Electric Vehicles
The most obvious problem for electric vehicles is that a significant proportion of electric power does not, currently, derive from renewable sources. Until that changes all we are doing is hiding, rather than solving, the problem. In fact, right now (and putting aside the challenges of a practical charging infrastructure), if all the cars currently on the road were to be replaced with electric vehicles then global CO2 emissions would actually increase rather than decrease.
Unfortunately, while the situation is improving, the dream of producing high volumes of green electricity in a very short amount of time is hampered by the costs and difficulties associated with quickly realizing generation from renewable sources such as solar and wind. Clearly increasing the production of energy from green sources is a must and ever-stricter targets should be imposed by law. This will not only make electric vehicles greener but also help the de-carbonisation of every electrically powered device and service.
But even if we address the challenge of more renewable energy sources this does not change the fact that charging electric vehicles takes much longer than refuelling conventional or hybrid vehicles. This, coupled with relatively limited range, means that electric vehicles are still not practical for long journeys. What’s more, making charging faster means making the efficiency worse - speedy converters are typically less efficient and consume more energy than slower chargers. And even the fastest chargers wouldn’t match the speed of filling a tank with liquid fuel.
That’s why a focus on hybrid vehicles combined with legislation that mandates lower emissions and higher percentages of biofuels¹ offers the real possibility of highersustainability today while addressing both speed of refuelling and range limitations. In parallel we need to continue research and development into other ways of achieving the overall goal of reduced emissions. For example, thermo-chemical methods of converting CO₂ into fuel using sunlight (see https://www.sciencedaily.com/releases/2016/07/160707101035.htm) seem promising and should be investigated fully before investing large sums of money in the ‘wrong’ infrastructure.
¹ If we switch today and we use rapeseed or similar, then the surface needed is too high. By contrast, significant improvements can be achieved with algae (last ones are made 46% by lipids, very good for biofuel, but the process is still too complicated. But the same can be said for electric panels, and algae can be cultivated into the sea with higher surface, much more solar energy, and so on. So my point is creating more and more severe regulamentations rather than forcing a technology.
Another obvious problem for the electric vehicle is a sustainable and practical charging infrastructure. Embarking on a long journey in an electric vehicle requires meticulous planning of stops for charging and extended journey times as we wait for batteries to be replenished. It is almost as if we end up serving the car rather than the car serving us!
While the electric car makes more sense for short journeys there is another issue when it comes to charging. Specifically, if we charge millions of vehicles simultaneously (for example during evenings when everybody gets home or in the mornings when parking at work) then there will be peaks of demand that no electric grid (either today or in the foreseeable future) is able to support. Improving the situation to better handle peak demand will require unprecedented investment in grid infrastructure as well as the development of complex optimization algorithms.
And then we come to the battery, which at the moment is simply too heavy and bulky.
Anybody that knows even a little about engineering understands that in order to produce eco-friendly cars in a simple way you need to make them lighter. Once again, the electric car introduces a problem that we currently do not have by actually making the vehicle heavier. Furthermore, lithium, a key component of batteries in electric vehicles, is not exactly an eco-friendly mineral. Not only are lithium mines an enormous ecological problem that must be addressed, but there are also few countries producing lithium, some of which are neither stable nor reliable. Indeed, they present very real concerns when it comes to establishing geopolitical links and trading relationships.
And, of course, time between battery charges also depends on how the vehicle is used. Optimizing consumption requires considered and economical driving rather than rapid acceleration and high speeds. And while it may not be how marketing departments want to promote their vehicles, responsible communications should deliver the message that if you accelerate quickly and drive fast then expect to pass many hours in the service station!
But what about passenger comfort? One problem that few people seem to consider or care about is the impact of air conditioning and heating. Vehicles transport people who expect a cool car during summer and a warm one in winter. However, use of air conditioning can reduce the electric car range autonomy by 33%, a problem that is not relevant for traditional cars. During the winter it is even worse. A traditional car isa co-generating system and, as anyone who has attended a mechanical, industrial or mechatronic engineering course will know, co-generating systems are highly efficient. This means that the heating, in effect, comes for free. However, the heating in an electric car is paid for in terms of an increased drain on the battery (and corresponding impact on range autonomy) of as much as 40%.
I want to underline that I am not nostalgic about the ‘good old V12 aspirated engine’ or the internal combustion engine. I strongly believe in progress, and progress means taking care of the planet, polluting less, increasing performance, taking care of people and making quality of life better rather than worse. We need to consider avoiding problems that don’t need to be solved and make sure we look at the overall objectives. Countries should concentrate more on defining precise numerical goals (for example in terms of carbon neutrality) and less on which specific technology to promote and making sure that investment is given to research activities (rather than trends).
At present, we are not embarking on enough activities that will drastically reduce emissions in line with net zero goals. Encouraging the production and take-up of hybrid vehicles while incentivizing sustainable fuels is one way that we can move towards achieving this objective through significant and immediate advancements that deliver high margins of improvement.
At the same time I would love to see more honest communications from manufacturers rather than speeches aimed to please a public which is concerned about the environment but does not necessarily have enough information on which to base key decisions. If the goal is to sell and ecology is the new marketing, that’s OK. But if we really care about the planet and the people, maybe we should do what is right and not what is trendy. And one thing that is definitely right is admitting that there’s a lot to be done, a lot to study, and a lot to improve quickly.
Finally, we need to recognize that a single vehicle type that is suitable for each and every individual need while meeting environmental sustainability goals does not exist. If you are living in California, traveling a few miles per day, producing your own energy from the solar panels on your roof then a Tesla may well be the perfect solution. But this is unlikely to be the case if you have to cover long distances in short periods of time and the majority of your region’s electricity derives from fossil fuels.