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Today, AutoVolt gets behind the wheel of the Toyota Mirai hydrogen FCV.
I (JM) have been a passenger in one before and have fairly extensive experience in the Hyundai ix35 FCV so am looking forward to finding out the differences between the Mirai and it, plus how it compares to other Toyota's like the new Prius. One thing I can already mention is the fuel cell stack is beneath the front seats and so is more audibly noticable than the Hyundai's, which is under the bonnet.

Any questions?

[Image: mirai-1600x900_tcm-11-323560.jpg]
JM
I look forward to reading the article.

I don't know what to ask with hydrogen.

Can it be operated in a Battery only mode?
What do you mean audibly noticeable? I never been in FCV.. what kind of noise does the FC make?
(19-04-2016, 02:09 PM)RyanD Wrote: [ -> ]I look forward to reading the article.

I don't know what to ask with hydrogen.

Can it be operated in a Battery only mode?

That's a fair point. Hydrogen questions are generally much the same as EV questions, e.g. range and refilling time (300+ miles and about 5 minutes for the Mirai, respectively). But then there are questions like what's it like in cold weather, what can go wrong, where can you fill it up etc. Although I've just made a rod for my own back, these questions and more will be answered in the article! Nonetheless, to answer them in brief: the Mirai can be run in the cold, fuel cell stack's need to be operated at a warm temperature and they do warm up with use. Cold starting is fine and Toyota has tested the car in -22º. What can go wrong is essentially the same as a normal EV, i.e. electrical components and of course the usual mechanical components that all cars share (brakes, wheel bearings and the like). The hydrogen tank(s) are unbelievably safe, e.g. you could put 150 Toyota Aygo's ontop of one and it wouldn't crush. There is a whole long list of interesting tests it undergoes. The car is arguably much safer than a petrol/diesel car. Filling stations i.e. infrastructure is possibly the biggest negative against the car as there are currently only a few across the UK, with most being in the South East. However, cars like the Mirai are intended as a "chicken" so that an "egg" can be created, or in other words, without hydrogen cars being made, nobody would make an infrastructure for them. There are new confirmed hydrogen filling stations opening around the UK this year and beyond.

Battery only mode… well sort of but there's not really any need. Effectively, the car has a >1kW battery that the fuel cell stack recharges and that is used for capturing any regen. Fuel cell stacks can adapt to demand extremely quickly, but batteries tend to be used in conjuction with them to provide an even power delivery. So, there's effectively no discernable difference between when the car runs from the battery or the fuel cell stack.

(19-04-2016, 03:52 PM)LaiLa Wrote: [ -> ]What do you mean audibly noticeable? I never been in FCV.. what kind of noise does the FC make?

It's hard to describe, but if you've ever heard a loud cooling fan start up on a petrol engine in traffic on a hot day, then it's a bit like that only without the petrol engine of course. Most of the time, occupants are unaware of any noise as it is quieter than road/tyre noise. However, if power is demanded for example when accelerating hard, the "whooshing" noise can be heard. In the Mirai, the front occupants chairs sit on top of the fuel cell stack, so the noise is more noticable than the Hyundai ix35 FCV's setup, which houses the fuel cell stack under the bonnet.
I do like the noise EV vehicle makes, so I imagine it's exciting to hear FC in action. Smile

300+ miles is similar to what my ICE car can do. There are no more excuses to stick to the ICE as soon as the infrastructure gets sorted out. In Europe there are couple projects to "connect" the countries through H2 filling stations on main roads, e.g. H2ME or EHA
(20-04-2016, 01:39 PM)LaiLa Wrote: [ -> ]I do like the noise EV vehicle makes, so I imagine it's exciting to hear FC in action. Smile

300+ miles is similar to what my ICE car can do. There are no more excuses to stick to the ICE as soon as the infrastructure gets sorted out. In Europe there are couple projects to "connect" the countries through H2 filling stations on main roads, e.g. H2ME or EHA

Yes and the UK has more stations coming this year and next - funding and a "green light" was given last year for (I think from memory) around 11 stations. It's a start.

Currently, only about 6% of hydrogen produced comes from renewable technology though, so there's still some way to go before hydrogen can be seen as a so called "green" alternative to fossil fuel. The current truth is ironically that 94% of hydrogen is produced from fossil fuel! However, of course, this can all change and very quickly too.
What about the waste products of the Mirai? Is there steam coming out of the exhaust or is there a water collected in a tank and then tipped out when full? Also where does the heat go from the fuel cells? Is it used for cabin heating or any other auxiliaries?
(21-04-2016, 07:39 AM)LaiLa Wrote: [ -> ]What about the waste products of the Mirai? Is there steam coming out of the exhaust or is there a water collected in a tank and then tipped out when full? Also where does the heat go from the fuel cells? Is it used for cabin heating or any other auxiliaries?

The waste product is water. About 0.8 litres is produced for every 10 km travelled. The system self purges itself while travelling, and yes, it appears as steam. However, there is an H2O button on the dash which the driver can press to manually purge the system of water. The idea behind this is if, for example, you park the car in a nice garage, you don't want it to dribble water onto it once you're parked. To help prevent this, drivers are encouraged to purge the system before entering the garage.

Fuel Cells don't run at any significant level of heat, so the water is only tepid (no worries of being scolded). The exhaust pipe is plastic and you can reach under the car and feel it. It's quite pleasant, in an odd way!

I don't know for certain with the Mirai, but in the Hyundai ix35 FCV, the fuel cell heat was used for interior cabin heating. It isn't instant like an electric heater, instead it takes a couple of minutes to feel the benefit. To my knowledge, there is no cabin pre-heating for the Mirai, unlike many electric cars, but there's no reason why that kind of tech cannot be installed in future models.

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I was wondering what would happen if all the cars on roads now would be H2 FCV..
Would the water vapor produced cause more global warming as it is one of the greenhouse gases?
I read this article: https://www.newscientist.com/article/dn1...house-gas/ and the scientist is saying that CO2 is much more harming than the vater vapour. According to this the CO2 sinks have limited capacity, but water can always be cycled e.g. vapourise, turn into clouds and rain and there isn't limit on rainfall.
But surely unlimited amount of rainfall can't be beneficial to humans...
I think that if millions of cars ran on hydrogen and produced H20 both as vapour and liquid, it would possibly have a net effect on the environment but I don't think we'd know what that is until it happened. Maybe mist and fog would become more common from the added humidity in the air? Instead of smog (smoke + fog), we'd have… err… mog (mist + fog)?!
I think one major benefit is of course that water is relatively harmless whereas the particulates we've been breathing for decades certainly don't do our health any good. Personally, I like hydrogen fuel cell vehicles but their infrastructure is my biggest worry. IF that can be sorted - and sorted right first time - then it has promise. If on the other hand there are only a handful of stations built over a short period of time and all using hydrogen from fossil fuel (steam reformation), then there's little benefit.
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