Second in my series of semi-regular (meaning I post when I have the time) posts where I go over popular tech myths, I’ll look at hydrogen as a fuel for cars. Will the hydrogen car kill the EV? And why did Elon Musk call hydrogen “a stupid technology”, and refer to fuel cells as “fool cells”?
I’m a happy EV owner, and have been for some time. I’ve driven the Kona EV and now drive a Tesla Model 3 Long Range. And yes, the logistics of driving an EV is different to driving an ICE car (I’ll put up a post on this at a later date).
But are EVs really the future? Or will they be obliterated by hydrogen vehicles?
First, let’s look at the two technologies, then compare them.
ICE, ICE baby
First, we have ICE (internal combustion engine) cars. They’re well-known to most, as they’ve been around for more than a century. Oil is drilled from the earth and refined into gas/petrol and diesel. This is then transported using pipes, tankers, and trucks, to gas stations, where it is pumped into the gas tanks of cars. The car’s engine then takes the fuel and burns in (the process is slightly different for gas/petrol and diesel), which makes for propulsion energy.
The advantages of ICE technology is mostly its history. It’s been around for a long time, and the entire logistical system and supply chain is in place. We don’t need to chagen anything to make it work. It is also a pretty effective mode of energy storage, and we’ve largely worked out the kinks of the vehicles using it (i.e., they don’t blow up as much as they used to).
As appareant as the advantages are, the disadvantages are equally obvious. Drilling for oil has immense environmental impacts, as does the combustion of the fuel. The two main problems are CO2 and particule pollution. CO2 is a gas that naturally occurs in a combustion process, and is tied to global warming. Particle pollutants come about because no combustion process is 100 % clean, and some of the impurities come out the tail pipe. These can cause a number of health issues if they’re breathed, including resperatory issues and cancer.
Power To The People
Most people know how EVs work. You have a car that runs entirely on eletrcitiy, with a drive train consisting of a large-capacity lithium battery and one or more electric engines (for instance several Tesla models have two, one on each axis). To charge the car, you need to plug it in to a power source. The simplest solution is to plug a dedicated charger into a wall socket, charging it basically like you would your phone. This is however very slow (if you’re lucky, you’ll get a handful of miles worth of range for every hour you charge), and not all home power grids can handle that kind of load for long durations. A better option is a dedicated charger, which you can install in your home (if you have your own drive way or garage) or you can access public charging stations, such as Tesla’s SuperCharger network. These are a lot faster. How fast depends on the charger and the car. But in best-case scenarios, you can charge several hundreds of kilometers in 30-60 minutes. Still a lot slower than pumping gas into an ICE car.
The advantages are that there are no emissions from the vehicle itself, and if the power on a given grid come from sustainable sources, it can be a 100 % green mode of transport. But even on all “black” energy made from all fossil fuels, EVs still have environmental advantages. Burning fossil fuels in an effecient power plant is typically less damaging than burning it in a smaller and less-effecient car engine. Plus, refining the oil also creates pollution, so at least we’re reducing the polluting processes. Also, provided you can charge at home, you basically don’t have to worry about refueling for daily needs (only for longer road trips).
The disadvantages are the range (an EV typically has a range up to 400-500 kilometers, where ICE cars can often go 600+ on a tank of gas). Recharging also takes longer, as stated above. Another challenge is access to charge points. While some countries are well into building public charge stations, but the network in most countries are still somewhat lackluster, and struggling to keep up with demand. Also, some countries’ power grids may need upgrades to handle the increased load as more and more EVs hit the roads.
It’s A Gas, Gas, Gas
A hydrogen car uses hydrogen, which is burnt in a fuel cell, and uses the energy released from this for propulsion. The construction of a hydrogen car is closer to an ICE car than to an EV, with a fuel storage tank and an engine that burns the fuel. However, when you burn hydrogen in a fuel cell, the only emission is water, which is what makes it interesting. Refueling a hydrogen car is also very similar to pumping gas into an ICE car, so a lot faster. Some existing gas station could also potentially be converted to hydrogen stations, making the conversion of the infrastructure relatively, at least for the end-point (more on that later).
So a green fuel that is as easy to use as gas, and can utilize existing refueling infrastructure? What’s not to like?
Well, there’s a lot to like, but hydrogen also has problems. Let’s look at disadvantages.
First of all, hydrogen in a completely free form is hard to come by (because physics and chemistry), so it needs to be separated from other componants. It can be done from water (more on this later), but mostly it is done from fossil fuels. This is often done by a process known as steam reforming, using natural gasses such as methane, but it can also be made from coal or biomass. And already here, we can see some issues. To make hydrogen, we have to use fossil fuels. And the process of steam reformation itself creates large amounts of CO2, which is not what we’re trying to achieve. Hydrogen can also be made through electrolysis of water, but this also requires large amounts of power. This power can be gotten from renewable sources, though, once we have the capacity.
The problem is that we’re using energy to create a fuel, and any time energy changes form, there’s a transition loss. A study by Ulf Bossel and Baldur Eliasson shows that of the energy (in the form of electricity) put into a process of creating hydrogen, only about 25 % is stored in the hydrogen, meaning we have a loss of 75 %. In an EV, we could put close to all 100 % of that energy into the car to run on. I say “close to” because there’s always a loss of energy when we transport it through the power lines, as well as when we charge and discharge the battery, but the difference is still striking.
Then there’s transport and safety. Hydrogen is the simplest and lightest element in the universer, so it takes up a lot of space. So strorage is a problem. Storing it in its gas state just isn’t feasible. The most common option is liquification, but that requires it to be cooled to almost absolute zero, and stored at this temperature. That’s pretty tricky. And cooling the hydrogen takes up about 40 % of the energy in that hydrogen, so a further loss. Compression is a better option, and what most look to, but while it can be compressed, it still takes up a lot of space. A car running on compressed hydrogen would need a fuel tank roughly 4 to 5 times larger than a gas tank for the same range. The best option is probably solid state hydrogen, but this an immature technology, that isn’t viable yet.
And all of this hydrogen needs to be transported. If we transport it using diesel engine trucks, we’re negating all advantages of the hydrogen. And if we use hydrogen trucks, we need evern more hydrogen to get the hydrogen to consumers, incurring a further effeciency loss. Electrcity can be sent through power lines with relatively minimal loss along the way.
Then there’s safety. Hydrogen has a few advantages here, in that it does not pool, so we won’t get spills as such. It will simply disapate into the atmosphere. It also is non-toxic. However, hydrogen also has some safety issues. It is invisible and odorless, and adding odorants like we do with some natural gasses doesn’t work as these pollute the fuel cells. So leaks can very easily happen (because the gas is so fleeting) and they are near-impossible to detect. Hydrogen also burns very, very easily. The energy from a cell phone (not a spark, but just the energy coarsing in the phone itself) can set it off, as can thunderstorms miles away. And when hydrogen does burn, it burns invisible, which has in the caused people to walk straight into hydrogen fires because they couldn’t see them.
That’s not to say that hydrogen can’t be stored or transported, that happens today, but it only happens under very tight, combersome, and expensive regulations.
Hydrogen is a difficult fuel, with a very ineffective production method, that has a significant environmental footprint, and several issues relating to transport and storage.
It’s also expensive, due to all these factors. A 2019 CNBC article, which is actually largely positive about hydrogen, compared the price of refueling a hybrid car in California, to refueling a conventional car, and at the time, a conventional car would cost some 40+ dollars to refuel, and the hydrogen came in at 55 to 65 dollars. And yes, since then, fossil fuels have become more expensive, but that has also hit hydrogen, as it is often made using fossil fuels.
From an environmental point of view, hydrogen won’t really make sense until we have enough surplus energy from renewable sources that it can cover all our power, and still have enough to make hydrogen to cover our transportation needs. But even then, we would need to produce roughly half as much power for transportation if we relied on EVs instead.
Bottom line is that while we’re in the middle of the EV breakthrough, hydrogen still needs its breakthrough. Will that breakthrough come? Maybe, but it’s not here yet. And even when or if it arrives, it will probably still make sense to just use the electricty itself, instead of using it to make hydrogen.
There are situations where electricity won’t work, though. Such as airplanes, or space travel. The energy needs of these modes of transport are just to great for a battery to be a viable solution. Here, hydrogen has an advantage, and this is where all the Power-To-X projects come in. They have their place. But as a source of energy for private transport, hydrogen is an unlikely contender.
UPDATE: Someone asked me what I believe it will take for hydrogen cars to overtake EVs. First of all, my take on this is purely from a technological perspective. Whether hydrogen becomes the dominant technology is also dependent on other things, such as marketing push by producers of hydrogen vehicles, lobbyism and political support, and a number of other factors. Maybe hydrogen will win, despite being the lesser technology and we’ll get a Betamax/VHS thing all over again.
But for hydrogen cars to become the better technology, a few things will have to happen. First of all, we need to crack the code to solid state hydrogen fuel cells, something that is not matured yet, not in a scale where it can be used for individual cars. Then we need to stop using steam reclemation and use only electrolysis of water to make hydrogen. And to do that, we need to convert enough of the power grid to sustainable, emissions-free power production, and produce enough of it to meet our currently electricity needs plus have a surplus large enough to produce hydrogen. And even then, we may still only need a smaller amount of surplus green electricity if we stick with EVs.
All of this is even without considering the development that EVs are likely to go through in coming years. Already we’ve seen range and charge times improve by leaps and bounds in recent years. So in other words, for the scenario above to come to fruition and hydrogen become king of the hill, we’re assuming that hydrogen technology improves exponentially, much more so than it has in the past decades, while EV technology will have to come to a screeching halt at its present level.
And do note that I say that hydrogen is not ready to be the dominant fuel technology. As I write further up in the post, there are vehicles with an energy need that an electric engine will struggle to meet, and with those, hydrogen can be a suitable solution. But it should remain a niche technology for now.
Sources
Why A Hydrogen Economy Doesn’t Make Sense, from Phys.org
The Truth About Hydrogen, from Popular Mechanics
Energy and The Hydrogen Economy, by Ulf Bossel and Baldur Eliasson
Cost to Refill, from California Fuel Cell Partnership
Musk Calls Hydrogen Fuel Cells “Stupid”, But Technology May Yet Threaten Tesla from CNBC
More California Gas Stations Can Provide H2 Than Previously Thought, Study Says, from Phys.org
Thomas Grønfeldt Senger 
Very interesting! Thanks for taking the time to explain all this.