mspohr
Well-Known Member
Might want to make a "for dummies" version which cuts it down to fewer slides but keeps the main points.
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Hydrogen vs. Battery
- Thread starter siry
- Start date
One of the most damning indictments of the H2 Fuel Cell technology, is where it sits today after many years of development as a powerplant option in it's own rights.
Toyota's Mirai compact 4-door is perhaps the only significant example, so we will use that.
4,084 lb for a compact sedan makes it among the heaviest compacts in history, if not the heaviest. While advertising 154HP of thrust, it simply does match other green powertrains in performance while being double the price of many "green" cars. Only the Prius can match it in a Slowest Green Car competition.
This is terrible engineering for a powertrain system. You normally avoid picking the worst power to weight possible when selecting powertrains because it affects everything from braking to bearing life. Not to mention efficiency or performance.
So even if you could justify refueling it with fossil fuel products and a heavy CO2 footprint, as an automotive powertrain it is simply a poor choice. It would be better for applications where weight was not as important like stationary power generators.
Toyota's Mirai compact 4-door is perhaps the only significant example, so we will use that.
4,084 lb for a compact sedan makes it among the heaviest compacts in history, if not the heaviest. While advertising 154HP of thrust, it simply does match other green powertrains in performance while being double the price of many "green" cars. Only the Prius can match it in a Slowest Green Car competition.
This is terrible engineering for a powertrain system. You normally avoid picking the worst power to weight possible when selecting powertrains because it affects everything from braking to bearing life. Not to mention efficiency or performance.
So even if you could justify refueling it with fossil fuel products and a heavy CO2 footprint, as an automotive powertrain it is simply a poor choice. It would be better for applications where weight was not as important like stationary power generators.
Wow 500 lbs more the a Bolt. Curious what makes it so heavy? Obviously not the powerful electric motor. I know in BEVs it's the battery - so is it the fuel tank here? Or the conversion stack?
I have no idea why a small car would weigh that. The Bolt has an 800lb battery in it.
I am assuming the seats are not made of lead on Mirai, nor are the tires filled with sand. So it must be the powertrain.
Hydrogen tanks are heavy. For a 700 Bar tank, around only 5% is hydrogen by weight. Toyota claims theirs is an industry leader at 5.7%.
Thus for 5 kg of hydrogen, the total tank weight is around 100 kg.
Thus for 5 kg of hydrogen, the total tank weight is around 100 kg.
JohnSnowNW
Active Member
The tanks are heavy at 200 lbs, the NiMH battery is about ~100lbs, FC weighs 125lbs..., so there's 425lbs right there. The Bolt battery weighs about 960 lbs, but also provides a structural component of the vehicle. The tanks, nor the battery, or FC are incorporated into the structure of the Mirai.
The Mirai is also a full 28" longer than the Bolt...got to have room for those bulbous cylindrical tanks.
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By the way, thanks for the comments. I realise some of the slides are quite wordy. I was trying to strike a balance between overloading it and making it too basic such that detractors could attack it for not showing how those conclusions are arrived at.
In practice I plan to give this as a stand up talk to what I suspect might be a semi-hostile audience, and can talk around some of this stuff, but I also want there to be a version on the internet that people can link to when they see hydrogen b.s.
If some lay people can suggest what might be sensible to edit down then please do.
In practice I plan to give this as a stand up talk to what I suspect might be a semi-hostile audience, and can talk around some of this stuff, but I also want there to be a version on the internet that people can link to when they see hydrogen b.s.
If some lay people can suggest what might be sensible to edit down then please do.
Put the nitty gritty details in backup slides. They can be as thorough as you please. Keep the presentation slides themselves clean and streamlined; talk to the content and only dive to the backups if REALLY necessary.
More words = less attention overall, and less attention on you specifically, because humans will typically read first and listen second.
More words = more opportunity for opponents to challenge distracting and unimportant minutia.
More words = more reading [and thus less talking] on your part, which makes it seem like you don't actually underatand the subject matter.
More words = less attention overall, and less attention on you specifically, because humans will typically read first and listen second.
More words = more opportunity for opponents to challenge distracting and unimportant minutia.
More words = more reading [and thus less talking] on your part, which makes it seem like you don't actually underatand the subject matter.
I think there are two points that are missing:
1) You note that the Mirai is less efficient than EVs at 90 g/km CO2. To me that's not nearly as powerful as pointing out that it's noticeably worse than the 70 g/km Prius (according to Toyota). The Mirai emits more CO2 than a standard gasoline burning Prius. It's harder to fuel than a standard Prius. It's more expensive than a standard Prius. The Prius is strictly better than the Mirai.
2) Clean electricity is better used on the grid than for electrolysis. If you build a windmill that produces 1000 kWh per day, you can put that on the grid and the local natural gas plant will emit 550 kg less CO2. or you could use it to create 18 kg/day of Hydrogen and the local steam reformation plant will emit 100 kg less CO2. In other words, until there's a surplus of electricity, electrolysis is several times more polluting than steam reformation. and a Mirai running on steam reformation is more polluting than a Prius.
I've added the Prius to the comparison table and for good measure threw in a Porsche 911 Carrera 4S 
Your second point puts the whole issue very succinctly. I'm trying to find the best place to put that in the wrap up.
Your second point puts the whole issue very succinctly. I'm trying to find the best place to put that in the wrap up.
It's not happening. This will be the VHS vs Beta technology. . No one is going to invest in the infrastructure to install hydrogen stations (in the near future). I saw couple of years ago about some consortium planning to place stations on the east coast, before I purchased my 1st Tesla (2014) but here we are 2017. Automotive groups are pushing out for the EV charging stations across the US. The only industry that may do Hydrogen is ironically the big oil companies. So far you can only lease two vehicles and they are both in CA area. Too small a market to make the investment. Time to model 3 comes out it will be a mute point, as the Bolt and other full EV cars will be on the market. Hydrogen is a
JRP3
Hyperactive Member
Good series posted in another thread but relevant here Why fuel cell cars don't work - part 1 - mux' blog - Tweakblogs - Tweakers
WannabeOwner
Well-Known Member
Oil majors, car makers to push hydrogen technology to help cut emissions
"Oil majors, car makers to push hydrogen technology to help cut emissions
The heads of some of the world's biggest oil firms and automakers agreed on Tuesday to push for broader global use and bigger investments in using hydrogen to help reduce emissions and arrest global warming
... the chiefs of oil firms Total (TOTF.PA) and Royal Dutch Shell (RDSa.L) ... the CEOs of car makers BMW, Daimler, Honda, Hyundai, Kawasaki and Toyota as well as miner Anglo American and energy and engineering firms Engie, Linde and Air Liquide."
In another news feed I read that they plan to spend $10.7 billion over 5 years on this White Elephant ...
"Oil majors, car makers to push hydrogen technology to help cut emissions
The heads of some of the world's biggest oil firms and automakers agreed on Tuesday to push for broader global use and bigger investments in using hydrogen to help reduce emissions and arrest global warming
... the chiefs of oil firms Total (TOTF.PA) and Royal Dutch Shell (RDSa.L) ... the CEOs of car makers BMW, Daimler, Honda, Hyundai, Kawasaki and Toyota as well as miner Anglo American and energy and engineering firms Engie, Linde and Air Liquide."
In another news feed I read that they plan to spend $10.7 billion over 5 years on this White Elephant ...
I've updated the presentation to include a slide on this and a slide on the costs.
Taking the wholesale grid cost of electricity in the UK and the wholesale cost of water, and factoring a 10 year amortisation period for the electrolyser, it's clear that the base cost of this source of hydrogen cannot fall below £5 per kg at 2016 prices.
Now considering that the wholesale cost of petrol is around 25% of the retail price (after the retailers' margins, duty and VAT are taken into account) and we could be looking at £20 / kg or £100 to fill up the Mirai.
As the wholesale cost of electricity is forecast to reach £78 per MWh in 2025, by then you could be paying £7 per kg of hydrogen.
If onshore wind strike prices are to be taken as a guide for the idea of a renewables-powered site, these are already around £90 per MWh now. Therefore the true price of fully renewable hydrogen, even if the practical considerations are ignored, would be north of £8 per kg now before any other overheads and taxes are considered.
I haven't done costs for the steam reformed route, as that's a whole new rabbit hole of research.
Taking the wholesale grid cost of electricity in the UK and the wholesale cost of water, and factoring a 10 year amortisation period for the electrolyser, it's clear that the base cost of this source of hydrogen cannot fall below £5 per kg at 2016 prices.
Now considering that the wholesale cost of petrol is around 25% of the retail price (after the retailers' margins, duty and VAT are taken into account) and we could be looking at £20 / kg or £100 to fill up the Mirai.
As the wholesale cost of electricity is forecast to reach £78 per MWh in 2025, by then you could be paying £7 per kg of hydrogen.
If onshore wind strike prices are to be taken as a guide for the idea of a renewables-powered site, these are already around £90 per MWh now. Therefore the true price of fully renewable hydrogen, even if the practical considerations are ignored, would be north of £8 per kg now before any other overheads and taxes are considered.
I haven't done costs for the steam reformed route, as that's a whole new rabbit hole of research.
Is it noteworthy that the auto company with the most experience and IP in the area of FC automotive technology is not a member?
They currently make H2 Fuel Cell vehicles, but they are betting on battery storage instead for passenger cars. I wonder why?
JohnSnowNW
Active Member
I delike these headlines that make it appear the companies are going to be betting their own money, when it's pretty clear it's a coalition banding together to panhandle.
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