CitroJim wrote:
I think if they can get the styling right and a decent hydrogen distribution network going the they're on to a winner...
That Toyota are looking at fuel cells too will be a huge benefit...
I see fuel cells as far more promising than battery electric in the long-term. I see battery electric as a purely interim measure and somewhat of a dead-end.
Up until recently I would have been right there with you Jim regarding hydrogen fuel cells. But in the last few years my opinion has shifted.
I was a big proponent of (the theory of!) Hydrogen as a fuel for nearly 20 years, as it could be used both to power the then dominant internal combustion engine (a spark ignition petrol engine can run on Hydrogen with modest modifications to fuelling and ECU mapping, similar to an LPG conversion, and give a bit less power than petrol but more power than LPG) or with fuel cells to power electric motors.
It seemed like the ideal clean "universal" fuel since it could power both current internal combustion engines (petrol designs anyway) and electric cars via a fuel cell. Beyond cars you could also use it as a replacement for natural gas for home heating and other purposes. And the byproduct of burning the hydrogen ? Harmless water vapour. What more could you ask for ? At the time battery technology was nowhere near what it is today (I think this predates lithium ion completely) so batteries seemed like a complete non starter to me for serious electric vehicles. (In fact this remained true for nearly 20 years)
I vividly remember an article I first read around 1990 which I think was from a late 70's or early 80's edition of either Electronics Australia or ETI, (Dad literally had stacks and stacks of both!) interviewing an Australian inventor who was trying to patent a new more efficient and safer means of electrolysis and storage of hydrogen. He also had on show in the article a prototype petrol engine modified for hydrogen running, a modified gas heater and so on. I wish I could remember his name or find the article but I've so far failed.
The big problem with hydrogen was always that electrolysis was VERY inefficient, and storage was bulky and low density, because you had to store the hydrogen and oxygen in separate cylinders, or forgo the oxygen cylinder entirely but then get incomplete and not completely clean combustion since trying to use the oxygen in the air ends up trying to burn nitrogen etc, which is the same problem internal combustion engines have with NOx. In short burning Hydrogen in air instead of with pure oxygen is not nearly as clean.
The reason why electrolysis was traditionally so inefficient (we're talking about well under 30% here) is because to capture the hydrogen and oxygen separately you have to space the electrodes quite far apart so that one gas can be collected in one tube and the other case by another. We've all done that experiment in high school chemistry with the glass apparatus I'm sure! A wide electrode spacing in a very non-conductive liquid like water means very high resistance which means most of the power is wasted heating the water rather than electrolysing it.
To make electrolysis of a non conductive liquid like water even possible in the first place you have to contaminate it with something like salt, but even then the resistance is really high and efficiency is really low. Although he tried to beat around the bush a little in the article to hide what he was patenting, his "invention" was essentially the idea that you CAN capture the hydrogen and oxygen together and store them together safely using the right design of storage vessel.
If you can collect them together "pre-mixed", you can make the electrolyser MUCH more efficient by designing closely spaced and interleaved electrodes - think of the design of the plates in a car battery and you pretty much have the design of his electrolyser - very efficient because the electrode gap and thus resistance is so much lower, and there is a large surface area. The real secret of his invention though was probably the insides of the storage vessel, which I'm going to assume was some kind of honeycomb anti-explosion design which was probably novel in the 70's but not anymore.
It turns out that hydrogen and oxygen don't spontaneously explode at room temperatures even when mixed in the perfect ratio as they would be straight out of an electrolyser, so as long as you keep the pressures and temperatures in a safe range and design the storage vessel correctly its no more dangerous than a tank of petrol. Because it's pre-mixed in the correct ratio you simply need to meter the flow of the gas to control the output without having to worry about balancing a mixture, and because you are not burning air you're not producing nitrogen oxides etc... all very tidy.
I don't know what ever came of his plans, I did read a few years ago that he had passed away but other than that I don't know.
Anyway that was my position up until a few years ago, but seeing practical EV's from the likes of Tesla and witnessing the staggering improvements in battery technology I now really do think that Hydrogen Fuel cell cars will be the Betamax of the car industry and will not last more than about the next 10 years and they will eventually give up on them as weight, energy density and charging times progressively improve on batteries to the point where there is no point to a fuel cell car. (If you can get 300-400 miles from a charge that takes 20 minutes, do you really need more than that ?)
Also consider that hydrogen (or hydrogen/oxygen) fuel is a physical good that has to be transported somehow just like petrol and diesel - either by pipe networks such as the national gas network (except it would have to be another separately built out network, which doesn't exist yet) or by tanker or boat as petrol and diesel are now. On the other hand we already have a national electricity grid that can transport electricity from one end of the country to the other relatively efficiently without transporting ANY physical good. It's all just electrons bouncing back and forth on stationary infrastructure, so in that sense it is always going to be more efficient than pumping or transporting a physical good somewhere.
Granted there isn't enough capacity in either generation or transmission at the moment for everyone to be suddenly using electric cars, but it won't happen over night so as the demand grows the grid will have to grow with it. Just like the demand for oil refineries, petrol tankers and petrol stations grew with the increase in petrol cars...
One final point (which was the original point I intended to make in this post before I went off rambling
) is that batteries provide one VERY important feature that EV's of today need that fuel cells do NOT provide for. And that is regeneration. What use is braking regeneration if you have nowhere to store that energy like a battery ?
In a pure fuel cell electric car you would not have regeneration and would have to throw that braking energy away as ICE cars do, dramatically reducing efficiency compared to a battery EV with regeneration. So a practical fuel cell electric car will have to have either a substantial size battery or super capacitor as a place for regeneration energy to be temporarily stored. And in fact I believe that fuel cells are not able to provide high instantaneous output for Tesla like acceleration anyway, so you need either a battery or super capacitor as a ballast for instantaneous demand from heavy acceleration anyway, with the fuel cell acting more like a continuous charger.
Once you have a hydrogen/oxygen fuel tank, a fuel cell, AND a ballast battery or super capacitor, that is a lot of space taken up in your car to make a practical system. So for the reason of regeneration alone, I think fuel cell cars will eventually fail to catch on and battery, super capacitor, or a battery super capacitor combination is the way the future will go.
Maybe I'm wrong - maybe once demand for petrol and diesel starts dropping significantly due to EV's perhaps Petrol stations, seeing the writing on the wall, will start offering hydrogen pumps, but if Hydrogen EV's have already died on the vine by then it may be too late for them...
