#PowerToX Part IV: The disadvantages of hydrogen mobility and how we solve those
Most parts of this blog series were covering alternatives to the widely spread combustion powered vehicles which are responsible for a lot of human induced greenhouse gas emissions. While we did talk about the recently famous battery-powered electric vehicles (BEVs), there also was a discussion about hydrogen powered mobility, such as in fuel cell electric vehicles (FCEVs).
I was quite surprised that there are other mobility options which are not only just as sustainable as electro mobility but do have some additional advantages, right?
Exactly. As so often in life, there are advantages and disadvantages for both options.
Due to the battery’s weight, the range of BEVs is pretty limited and re-charging takes a lot of time. Even worse, the infrastructure of re-charging stations is pretty bad in most parts of the world outside of northern America and Europe.
On the other hand, re-filling your FCEV’s tank is just as simple and quick like you’re used to with a fuel powered car. Also, hydrogen is a very convenient way of storing energy and on top of all takes up a lot less weight inside your car.
Therefore, especially for longer travels or bigger and heavier modes of transport — such as trucks, busses, vessels and even airplanes — hydrogen presents a lot of solutions for BEV related problems.
This is quite astonishing — I didn’t even know about FCEVs. How come, this technology isn’t more famous, known of, used and implemented?
Well, as already discussed, there are some arguments against hydrogen mobility. There is a very big lack of infrastructure, so it’s simply hard to re-fuel your car, even if it was faster than re-charging your battery. Additionally, we’ve also already talked about the low efficiency factor. It costs a lot of energy already to even produce the hydrogen, so only about 30% of the total amount of energy is used to move your car. In other words, with the same amount of wind turbine turnaround, a BEV drives three times the distance than a FCEV.
Another big topic is security. As you might know, H2 (molecular hydrogen) is a very small molecule and therefore it is pretty hard to store without letting some of it lose into the air — it’s simply very ethereal. Being a very powerful source of fuel, it can also be very flammable, even starting with concentrations of only four percent.
Now these two properties make it pretty dangerous to handle hydrogen — as you can see in the following picture. The German passenger airship LZ 129 Hindenburg caught fire on May 6th, 1937. The most widely accepted theory on how it started burning was a leak prior to the accident. This way, hydrogen — with which the aircraft was filled completely — would have been ignited through any minor spark leading to the enormous fireball.
Tragedies like this led us to not use hydrogen in everyday life. We use different gases such as Propane (C3H8) or Butane (C4H10) for cooking, heating and other industrial processes.
This is why the existing infrastructure like pipes, devices and valves are designed for these kinds of gases and certainly not for hydrogen.
Well — that’s a bummer! You’ve just come up with this apparently great alternative to our battery powered cars and yet again it has such a big downside? Isn’t there any solution to that?
Glad you’re asking — because, yes there is! I have to warn you beforehand though as this is going to be deep into the chemistry topic again.
As you can see in the previously posted formula of Propane and Butane, the gases we use to generate energy usually consist of Hydrogen, represented through the “H” and Carbon (“C”). This is why they are called hydrocarbon gases.
Another one of these is Methane (CH4) which also makes up the biggest part of the so called natural or fossil gas, a naturally occurring hydrocarbon gas we are using for all different types of energy production.
Alright — but why do you annoy me with chemical formulas again?
Because we are actually able to produce those hydrocarbon gases ourselves. Simply put, there are chemical reactions to put together carbon and hydrogen — which was at the center of FCEVs. Thus, we are able to generate gases such as Propane, Butane, Methane or any mixtures of it.
This is great, because with those gases we can mobilize all sorts of vehicles, use our existing infrastructure for cooking and heating and even use them in a lot of industrial processes which currently are using natural gas. They can even be liquified and would therefore fit perfectly into the liquid-based petrol station utilities or petrol-dependent industries.
Phew! So, let me get this straight. After you’ve convinced me, how bad fossil fuels are and how hydrogen might be our solution, you’re now telling me that we should generate our own fossil fuels and gases synthetically? Yes, we were at the hydrogen — but what’s happening with all the carbon in these gases?
It’s a little confusing, I understand. And you’re also totally right — carbon is a very important factor here.
As you remember, burning is a reaction with the air’s oxygen. So, if you’re burning any hydrocarbon gas, the oxygen (H) will react to water (H2O) and the carbon (C) will react carbon dioxide (CO2). You might argue now that this doesn’t make anything better than normal fuel we’re using already?
You bet I will! Same old problem, isn’t it?
It would actually be the same problem, I agree. But now imagine that we’re capturing our C in the equation straight out of the air. You do know that there is too much carbon dioxide it in the air, causing the whole greenhouse effect in the first place. Now, if we would start to take the CO2 out of the air, split it up to carbon and oxygen we could create our own hydrocarbon gases by ourselves.
Yes, they would emit CO2 to the atmosphere, but only to the amount we removed it out from there. So, this technology would be just as CO2 neutral as the hydrogen process — the amount of CO2 in the atmosphere is constant. It’s like applying circular economy on our mode of transport.
With huge advantages, as theses carbon-based fuels can be implemented in industrial processes and the existing gas network.
Yeah — as if that was working!? You mean, we run all the atmosphere’s air through some filters and get the carbon dioxide out of it? I cannot imagine!
You are totally right! As already mentioned, it is very difficult to filter CO2 out of the air.
However, companies such as ClimeWorks (Switzerland), Global Thermostat (US) or Carbon Engineering (Canada) and a growing number of others are working on exactly this topic.
With the Swiss company, for example, you can now also offset your carbon footprint. This means, that they are already capturing more CO2 from the air than they turn into burned fuels or gases. It’s a big impact for our second biggest imperative: get CO2 out of the atmosphere.
Additionally, we could reduce the whole amount of CO2 in the atmosphere in converting it into something different than new fuels. There are first experiments and tests how to store the captured carbon without turning it into mobile power. ClimeWorks managed to store it back into basalt stone in Iceland.
For a deeper understanding, I recommend this TED talk by Carbon Engineering’s CEO.
Capturing plant of Climeworks
Source: https://en.reset.org/blog/climeworks-where-carbon-capture-meets-greenhouse-fertiliser-06122017
I gotta admit, this is rather fascinating. However, I’m afraid, I cannot take any more input for today
Oh, I understand that. Then let’s call it a day with the following summary:
We’ve talked about common combustion engine vehicles and their disadvantages for the environment. BEVs could be an alternative — but only for some use cases. They are, for example, not feasible for big vessels or airplanes.
This is where hydrogen mobility — in the form of FCEVs — comes in and Hyundai amongst others produces cars which work this way. While this technology is pretty fascinating, unfortunately, it also has very few downsides such as the mentioned danger through its fugacity and explosivity. For certain areas around the world it wouldn’t be feasible to change towards a hydrogen-based mobility.
Now this Part 4 of our series discusses hydrocarbon fuels. And to set it straight right at the beginning: these are not perfect as well! Let alone the very bad efficiency. After capturing CO2, producing the real fuel, burn it in cars again — you simply lose a lot of energy. But again, if we managed to have that production processes running on emission-free energy, that downside would not matter anymore.
Bottom line, we need to get out of burning normal fuel in favor of our climate. There are certain alternatives at hand, all of which have huge advantages and some disadvantages. What I would like you to remember is that we have possibilities to turn all transport carbon-neutral — we’ll just need a mix of all of these different technologies.
Stay tuned for our next part in which we discuss this mix a little more in detail and what it would mean for our energy ecosystem.
This blog is a part of a six part series highlighting a possible solution for fighting climate change and still meeting our energy demand.
The series is based on known scientific facts and is broken down as follows:
1. Why climate change is real, and why it matters
2. How greenhouse gases get into the atmosphere and who is responsible
3. An exemplary sector use case: Mobility could be run on non-fossil fuels
4. The disadvantages of hydrogen mobility and how we solve those
5. What are the consequences if we could transfer global energy supply to Power-to-X
6. What is likely to happen and what can we each contribute personally
