Why electrical SUVs are not the way forward in sustainable mobility.
The goal of this article is to explain why lavish use of renewable energy equates to emitting CO2. Cars are used as an example to make this more tangible.
(It is not the point of this article to compare internal-combustion-engine cars with electric vehicles.)
Why do heavy and big cars need a lot of energy to bring you from A to B?
Basically, a car consumes most of its energy on two things: Accelerating and pushing the air away that is in front of it.
The energy required for accelerating is directly proportional to the mass of a car. And the energy required for pushing away air is directly proportional to the surface area and aerodynamic performance of the car.
Therefore a big and heavy car always demands more energy than a light and small car under the same conditions. This a true for an electric-vehicle (EV) as much as for an internal-combustion-engine-car (ICE). Even though it has to be mentioned that EV’s can supply this energy much more efficiently than ICE’s since they are much less bound by thermodynamic limits.
Thereby we can conclude that EV’s are, from an energy perspective, a step in the right direction. But in the case of vehicles as big as an Audi e-Tron, Tesla Cyber-Truck or Tesla Model X this step might be too small to face the challenge. So let’s see how we can make bigger steps and what we gain along the way.
Understanding the opportunity cost of electricity:
So let’s suppose you were only to charge your electric-SUV with renewable energy. Doesn’t that make all this energy-saving talk irrelevant? Unfortunately, that does not work out in the big picture.
Even in a country like Germany, where close to 50% of electricity is coming from renewables, electricity itself only makes up below 20% of the total energy. (Electricity is one form of energy). That means the total energy provided by renewables is currently at around 10% and therefore needs to at least 10x.
So, now please answer for yourself: How many years will it take to 10-fold the renewable energy supply?
For these __enter your number here__ years, using renewable energy to charge an oversized car results in less renewable energy available to replace coal, oil and gas in the electricity grid. And even outside the electricity grid, since renewable energy can be used to create green-Hydrogen or E-fuels that would allow airplanes and ships to operate carbon-neutral or drive industrial processes that need temperatures so high they can not be supplied by electricity. (But yes, you heard right we have all the technology to realise climate-neutral flying, we are just missing enough renewable energy to drive those processes.)
Even if your country were to produce more renewable energy than it consumes, there would be the opportunity cost of exporting it.
These opportunity costs are real, and they delay the progression to a renewable economy!
I am bashing a lot on big cars here, but the same applies to other wasteful energy uses. The International Energy Agency suggests retrofitting houses to be more energy efficient for heating and cooling, increased ride-sharing, car-free cities and less single-use plastic. Less material consumption, in general, is favourable since every product has an embedded energy-use of its production and transportation.
I just used cars as an entry point to make you realise that we can not afford to treat energy as something super abundant when the actual supply of renewables is still small and won’t 20x over a single decade. “Why 20x?” you may ask…
The miracles we can not fully embrace yet
Do you still have your __number of years__ at hand? Because we need to realise something more.
Firstly, historically our energy demand has sky-rocketed, and there are around 760 million people who do not even have access to electricity yet. We are not dictated by our past, so we can form the trajectory of this curve. I think we can flatten it, but it is unlikely that it will decrease since so many people still need more energy to supply basic human needs. So you will have to add some years to __your number__.
Secondly, there are these wonders of modern science and engineering that could make up for many of our past and current mistakes if we rolled them out on a scale. There are facilities operational today that do miraculous things, like sucking CO2 out of the atmosphere or creating freshwater from saltwater, indoor farming or turning polymers into monomers (a form of actually recycling plastics. Most recycling done today is down-cycling).
But all these wonderful inventions suffer the same problem. They require vast amounts of energy to have a meaningful impact. So it would be great if we had some renewable energy that was not busy replacing fossil fuels and could actually drive these processes without additional emissions. So we need to add some more years or decades to the __insert your number here__ years we thought of. These processes are a good shot a trying to reverse damages humanity has caused so far, but we can not embrace their power without more renewable energy.
I hope you agree now that for the next decades, renewable energy is needed to replace fossil fuels, and even at the point where fossil fuels are fully replaced, we still have more valuable ways to spend energy than to charge oversized cars or indulge in material-over-consumption.
What is the lesson to be learned here?
I am fully aware that this message of frugality is a very unappealing one in a culture where we enjoy wastefulness. But looking into the facts and numbers, I can not come to a different conclusion than the following:
For the next decades, things and practices that use energy wastefully can not be considered sustainable. Simplicity and efficiency have to be core drivers of our sustainable transformation.
It is important that we do not think that everything driven by electricity is automatically sustainable, which is currently a very popular claim (you will come across it soon if you keep an eye out for it). As we saw, not even everything powered by renewable electricity puts us on the right path. The goal of this article was to make you aware of this pitfall in general, and huge cars were the unfortunate victim for a concrete example. But after so much nay-saying, I feel the urge to give some constructive alternatives.
So what is the alternative, then?
Wherever we can, cars should be replaced by walking, biking, or placing many people behind one surface area, which is a nerdy description of busses and trains. This is mainly achieved by designing our cities to reduce the need for travelling long distances and by providing safe bike paths and convenient public transportation.
(And maybe public transport would sound much cooler to you if there was as much visionary thought, capital and hype going into it as into Tesla or flying cars.)
An electric vehicle is probably the best choice where a car cannot be replaced or is very hard to replace. In these cases, energy-efficient cars should be the first choice.
There you have it; this is how we make bigger steps and make our cities more livable at the same time. With these reductions, we make it easier to lift people out of poverty by providing electricity, get closer to enabling zero-emissions flying sometime in the future, and use miraculous technology to minimise further and reverse some of our impacts on the planet.
This blogpost was inspired by the book “Renewable energy without the hot air” by David MacKay.
