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Random Thoughts About The Future - Cars

TL;DR: I believe we overestimate the capabilities of battery driven cars and ignore other possibilities, such as fuel cells or grid connected vehicles.

Since my master thesis is now finished, I have some more time for other things. There are several things I plan to write about, including my thesis itself. One topic that gets a lot of coverage without really going in depth is the future of cars. In many ways Germany is the land of cars: We have the fastest roads. We not only build a lot of cars (Volkswagen is almost the biggest car manufacturer), but we also build the high end ones, which everyone desires (say BMW, Audi and Mercedes). Furthermore, a lot of jobs in Germany depend on the automobile industry, some say every seventh, but in reality it’s probably not that much.

In a recent discussion someone told me that it is impossible that the big German carmakers do not have a plan for the future – they must have because it is their job. I argued that it was not the big mainframe companies who prospered through the PC age and not the big phone manufacturers that build our smartphones to day – so why should the carmakers of today deliver the transportation of tomorrow?

What the transportation of the future will look like is the key question. In other words we have to ask: What job does the car for us and what job has a new the techology to do, when oil gets too expensive to burn. This question does not get asked enough. We only try to replace what we have with something similar; instead of making or at least dreaming about something that is better suited to do its job. Or as Henry Ford said: "If I had asked people what they wanted, they would have said faster horses." What most companies do at the moment is, take a car with a combustion engine and put a battery pack and an electric motor in it – seems like a “faster” horse to me. On the other hand, the first car, built by Gottlieb Daimler in Germany, was pretty much a horse wagon with a combustion engine.

The car enables us to get from A to B whenever we want, with almost all the luggage we desire and virtually no matter where A and B are. It does that, with a reasonable price per distance, a reasonable price per car and with adequate speed. Furthermore, a car is easy enough to drive, anyone can learn. You can go faster via a small plane, but you lose a lot of the flexibility and flying is much more expensive. Plus you will need years to learn how to fly. On the other end of the spectrum is public transport. To go by bus or train is usually cheaper, but you again lose a lot of flexibility, however, you do not have to learn anything. Well, except how to navigate the overly complex ticket vending machine. Carrying a lot of luggage is more exhausting because you not only have to get it to the next bus stop or train station, but you also usually have to move it several times between different lines.

One thing we tend to forget is, that we only can travel that easily by car because of the entire infrastructure that we build around it. First of all we have roads everywhere. Sometimes this seems so normal that we tend to take it as given. Imagine if we somehow came to the conclusion that we would use planes for every longer distance trip, so that there would be no road network between cities, no motorway and no interstate. The world would look very different then. Secondly there is a very dense network of gas stations, car dealerships and car workshops that support our cars. There are some places in the world where you do not have such infrastructure, like in parts of Siberia. In such places driving suddenly becomes a much harder undertaking, involves much more planning and gets a lot slower.

In reality there are two parts that make up the car experience if you will: the car itself and the infrastructure. We tend to see trains as very limited, because you need to build railway lines everywhere to use them – but that is exactly what we did for cars. You could argue that a road is much more versatile than a railway lines and that we as mankind used roads long before the car was invented. But how many cars modern cars can you drive for long distances on the roads of the middle ages?

But let‘s focus again on the vision of the electric car, its shortcomings and possible solutions, which I think are overlooked a lot of the time. The idea of the electric car is really old and simple: you combine chemical electricity storage with an electric motor, put that in the body of a standard car and you are ready to go. What you get is a car that drives silently, has a lot of torque and needs a lot less mechanical parts. It is even simpler to drive than a car with combustion engine because you don‘t need a clutch or gearbox. There is one severe problem though: energy density.

Energy density means: How much energy one can store (and then easily release) in proportion to the weight of a certain system. In a lithium ion battery you can store about 0.5 MJ per kg while one kilogram of gasoline can release about 43 MJ. It is much harder to put the energy back into the gasoline than into the lithium ion battery though. In other words you need about 80 kg of battery system to replace one kg of gasoline. This results in heavier cars, because the loss of mechanical components does not compensate the weight. In fact accumulators are so heavy that you cannot pack enough of them into one car to get the same mileage as in a gasoline car. The famous Tesla Model S weighs 2.1 tons and can drive up to 480 km. A comparable Audi A6 or Mercedes E class weighs between 1.6 and 2.0 tons and has a total mileage of up to 1000 km. Even though the whole system in the electric car is much more efficient – it can transform a higher percentage of the stored energy into movement (or kinetic energy) – does not help. This is the energy density problem. We will discuss it in the next few paragraphs.

There are some more problems coupled with it. Refilling a fuel tank is easy and reasonably fast, but charging a battery instead takes much more time and in the case of li-ion accumulators is rather complex. This becomes especially problematic when you want to drive a distance longer than it is possible with one charge. One solution is to replace the whole battery pack with a new charged one. Tesla Motors demonstrated that this is a technically feasible solution but it may have some economical problems because batteries age. But that is only a problem for the business model. Tesla could track the usage of every battery a driver uses and charge him accordingly. The Question might be if this would kill the price advantage of the electric car. If you look at the cost of "fuel" (a better term might be energy) per kilometre the electric car can easily win. You need about 20 kWh (Tesla Model S) per 100 km which will cost you about 5€, in comparison you will need at least 6 L fuel per 100 km for a price of about 9€. But if these costs suddenly include the compensation for the aging battery, it does not look so bright anymore. A new battery will set you back about 10.000 € and will last 200.000 km, again these numbers are from Tesla, for 100 km this means 5€ for the battery.

A minor problem is that eclectric motors work so much more efficiently than combustion engines that there is not enough heat for heating the passenger cabin and since the energy you carry in your battery is very limited you are unwilling to spend any of that for heating. Driving in the winter, time will be even worse than now.

A much bigger problem with electric cars seems to be that they are not only expensive, but in addition to that the process of making them does not appear to scale (get cheaper with mass production). This is because a lot of the minerals used to build the batteries are in short supply and will become more expensive if demand rises. The next problem might be where the energy to charge all the electric cars should come from if we abandon oil and coal, but we will ignore this one for now.

While electric cars still can transport us from A to B they limit the distance between A and B. Aside from that; they seems to be and to remain expensive.

One solution may be, to make private transportation public, via car sharing. Anytime you need a car, you just grab one from the next sharing point and drive where you want to drive. If your destination is further away than the reach of the car, you just stop by a sharing point along the way and grab another one. While this is a very good solution for big cities and a lot of everyday driving, it mostly ignores problems with large amounts of luggage. How many times do you want to repack your car on the family vacation trip? How many times a day would a traveling businessman or salesman want to change his car? Even though we are talking about cars, imagine the same system for trucks – almost impossible.

Let‘s not forget another fact: not all people live in big cities. Even with rising costs of transportation in the future this will probably not happen. Depending on the country, the urbanisation might be on different levels, but even in the highly developed countries you still have 9% (Japan) up to 40% (Portugal, Greece, Ireland) of the population living in rural areas. How well can car sharing work for them? What if a shared car becomes stranded in a small village? How do you share a car if you need it every day? The solution of the shared electrical car seams worse here than what we already have.

One way to solve the energy density problem is to make cars independent of energy transportation – you just connect them to the grid. Just like an electric train or a trolleybus. There are even ideas to transfer energy wirelessly via induction. Imagine you are driveing on a motorway; your car connects to the overhead wire and switches into autopilot, to charge its battery and take over driving for you while doing so. You can lean back and take a nap. The combination of connection to the power grid and the autopilot are actually separate things, but they fit very well together. You do not want to manually connect to the power line and whilst trying to overtake someone forget to unlock your connection first.

The ability to connect a car to the power grid for long trips would mean we could downsize the battery pack to last only for 100 km, with a small reserve for cold days. This would be sufficient for a shopping trip even if the next city is a bit further away. This would lower the cost of the car dramatically. We could even switch to other battery technologies (apart from lithium ion) that are much cheaper and widely available. The technology for pantographs (connection to the overhead wire) is also common and established. The obvious question is: what about the entire new infrastructure? We will need new infrastructure anyway; the question is what will be the best investment?

Let‘s not end the discussion of infrastructure here. If we consider building a network of filling stations either for hydrogen or for battery charging/exchanging versus some kind of system to connect cars to the grid on the highway, the big difference is who is going to finance it. A network of filling stations can be built by numerous companies as long as a standard connector for filling is established. The grid connection system instead will probably have to be founded by the state. My personal standpoint is that infrastructure should be provided by the state, like roads, water supply, electricity and telephone/internet connection, but your mileage may vary. Maybe a government-run project to build new infrastructure as a beginning of a new century and to overcome the current crisis is not such a bad idea.

The possibilities of cars that can drive on their own is another, not so distant, future prospect that I believe is overlooked a lot of the time. Some of us view driving as a fun activity, like as it would be a small adventure every time, or even a race – and for sure there are times when driving is fun. Most of the time however we do not feel any kind of fun when driving to the supermarket though the rush-hour, or when we drive home from work like we do every day, or when we drive several hundred kilometres with a fully loaded vehicle to arrive at the beach even more stressed and ready for a holiday than when the trip begun. For all those times a self-driving car would be marvelous – just get in, set the destination, and lean back. That would be much more joy than the cars we have today. A car that is able to navigate and drive on its own would even allow for a better shared car experience. Just tell your service provider when you need a car and it will be in front of your door.

Another solution for the energy density problem is to just not exit the era of liquid fuels. The usage of fuel cells in cars made a lot of noise in the early 2000s, but since then it seems that nothing has happened on the hydrogen front. The contrary is true. Toyota as well as Nissan, Honda and Mercedes-Benz have continued development of fuel cell cars and plan to release them to mass market in 2014/15. The cost of manufacturing is still higher than for a normal car (about 20%) but this is nothing unusual for a new technology. The Toyota fuel cell prototype FCHV was already available for leasing in Japan.

The good news is that liquid hydrogen can store even more energy than gasoline, which translates to fuel cell cars that have a total mileage of about 800 km, like we used to get from fuel. The problem with liquid hydrogen is that it will not stay liquid so easily - in fact hydrogen will not stay where you want it to be in any form easily. Hydrogen at normal pressure and room temperature is a gas. In contrast to a battery with a fixed energy density, you can compress or liquefy a gas to raise its energy density. You need either a very low temperature to make it liquid or high pressure to store hydrogen in a form that is dense enough to be competitive. Since it is not easy to keep things at low temperatures, the only feasible way to store hydrogen in a car is in a very high-pressure tank (700 bar). This is because hydrogen atoms are so small that they tend to leave a normal the tank very easily right through it‘s walls. With a combination of several synthetic materials it is possible to reduce these diffusions to an acceptable level, so we can mark this problem as solved. The fuel cell cars weigh only about 100 kg more than their combustion engine counterparts and use the same amount of platinum in there fuel cell than a normal car in its catalytic converter. Sounds perfect right? All we need is a network of hydrogen refill stations and we are set.

The production of the pressurised hydrogen though uses a lot of energy. To fill a tank with hydrogen at a pressure of 700 bar you need the energy of 12% of the hydrogen you fill in the tank. That means you not only need the energy to produce the hydrogen, you need 12% more to store it. But once again we come back to the question of energy later.

Another possibility is to produce synthetic oil. That may sound strange but the qualities of oil as energy storage are so good that a lot of people are working on projects to produce cheap oil without drilling for it in the ground. One way is to grow special algae that can be used as fuel. There are several different approaches, but until now it does not seem like they will be successful in the near future. Nevertheless it might be part of the solution to keep cars with combustion engines around and fuel them with synthetic oil produced from algae.

What about combustion engines anyway? They are probably not completely going away but with rising prices for fuel they will become more of a hobby. We do not use sailing ships for transport anymore but there are still a lot of people who use them just for fun. The same can be said for horse-drawn carriages and so on.

A more utopian version for the energy density problem could look like this: You have to travel to a bigger city, say it is 500 km away, you have a lot of luggage and the trip has to start tomorrow. You pull your smartphone out of your pocket and type in your destination and the time you plan to start. Your phone will suggest an appropriate route on a car train and book your car. The next morning the car is waiting in front of your door. When you have finished loading you, or your car, drives to the next train station several kilometers away. The car train leaves every hour, your smartphone knew that and suggestet a time early enough to catch it. Once your train has reached its destination town your car will drive you to the address you entered yesterday. That way your car will need a much smaller battery, same as in the grid connection example. We already have the technology to integrate different means of transportation like that. The question is if something like this will be fast enough compared to traveling by car and whether it can deliver enough throughput for the big routes. It will need even more new infrastructure.

Now you might expect some words about the question of where the energy to power electric cars might come from. When I started writing about this so many thoughts crossed my mind that I decided they should go in another article.

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