GRA
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Re: Toyota Mirai Fuel Cell

Mon Jul 09, 2018 7:08 pm

Oils4AsphaultOnly wrote:
jlv wrote:
mux wrote:Really, the only reason gasoline refueling is so relatively quick isn't due to the high energy density of the fuel alone, it's mainly because of how incredibly widespread gas stations are so you can always find one along your itinerary.
I don't see that at all. I don't think 3 minutes pumping gasoline to put in 400 miles of range has anything to do with how widespread gas stations are.


Have you factored in the travel time to get to the gas station? If there wasn't one around the corner, you'd have to make a trip to the gas station (could be a 5-15 min detour). You could combine it with a costco run, but now you have to add a 15-min line-wait.

Sure, that can be an issue locally, but on road trips? Where's the gas station on an interstate? Right off the exit, usually along with a few others plus a collection of fast food restaurants and maybe motels. And for added convenience, odds are there's such a collection of stations at every major junction, plus gateway towns to major recreation areas, and sometimes inside those areas, and generally there'll be one station no more than every 30 miles apart. Regardless of the type of energy storage and replenishment, that sort of density is necessary to maximize speed and convenience on trips, and Tesla has devoted most of their SC construction this year (in the U.S., at least), to providing that density along major routes, to the detriment of expanding the network's coverage to new areas.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

GRA
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Re: Toyota Mirai Fuel Cell

Mon Jul 09, 2018 7:24 pm

mux wrote:The point is that you're never filling up an EV completely and charging speeds are going up so fast that we're rivaling gas pump dwell times. A 350kW DCFC from 20-80% means you're only there for about 7 minutes. That is barely more than typical gas station visits, in fact, it's slightly below the average gas station visit in my country.

So if H2 infra isn't being deployed nearly as quickly as EV DCFC and the charging times are getting reduced by so much, where's the USP of any high-density fuel?

You seem to be arguing against yourself. Yes, charging speed are increasing, something that's much needed if BEVs are to compete with ICEs for long trips. But why should that be necessary, if refueling speed doesn't matter? The reason people 'never fill up an EV completely' is because it's very slow and also increases degradation, something that doesn't happen with liquid or gaseous fuels. When I'm on a road trips, I'm always filling up my ICE completely, to maximize my options and minimize my required stops. There's simply no reason (other than high-priced fuel in that particular location) not to do so.

350-400kW charging, once there's a car that can actually take that, will be a major step towards full ICE replacement. But will still don't know what such charging will cost, and it will still be far slower than liquid or gaseous fuels can replace range - retail gas pumps are limited by regulation in the U.S. to 10 gpm, so even at 20mpg that's 200 miles/min compared to say 360kW = 6 kWh/min. x say 4mi./kWh, or 24 miles/min.

If we can simultaneously increase the range of those BEVs, it may not matter. I've been saying for a long time that 4 hours at freeway speed while using the HVAC system, plus a reserve, would likely be considered adequate for the vast majority of consumers, if they could recharge and do the same thing again without degradation while eating a fast food meal. 2 hours as above, alternating short and long stops, says 20 minutes (incl. food) and 10 minutes for stretching/bathroom, might be acceptable to many. But the existing paradigm is 4+ hours as above, with only 5-10 minutes including a bathroom visit required before repeating ad nauseam, adding longer breaks wherever you wish, not where the car makes you take them.
Last edited by GRA on Tue Jul 10, 2018 5:18 pm, edited 1 time in total.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

GRA
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Re: Toyota Mirai Fuel Cell

Mon Jul 09, 2018 7:34 pm

GetOffYourGas wrote:
jlv wrote:
mux wrote:The point is that you're never filling up an EV completely and charging speeds are going up so fast that we're rivaling gas pump dwell times. A 350kW DCFC from 20-80% means you're only there for about 7 minutes. That is barely more than typical gas station visits, in fact, it's slightly below the average gas station visit in my country.

So if H2 infra isn't being deployed nearly as quickly as EV DCFC and the charging times are getting reduced by so much, where's the USP of any high-density fuel?
OK, I see that logic!

Of course, once you toss in the ability to DCFC at 350kW at a reasonable cost...

Of course, we are talking here about the occassional road trip. What we are missing is the elephant in the room - the daily commute. This is the bulk of most people's annual mileage. How much time do you save in a year by charging while sleeping or working (i.e. about 10 seconds/day to plug/unplug your car) versus travelling to the pump (gas or H2) once a week and standing there for 5 minutes while pumping fuel? I know it's a change in mindset, but I'll take the slightly longer road trip over the weekly fuel stop any day.

But going further, the last time I took a trip beyond my car's range, I simply timed my charge stop to coincide with a meal. So even my 40 minute charge session took considerably less time out of my trip than gassing up. If I had to buy gas, I would have eaten dinner and then had to go to the pump for 5 minutes to refuel.

All true, for those who can charge at home. For those who can't, which is currently most of the world's car-owing population, you have the same issue of time spent driving to/from the station, plus a much longer wait once you get there, and owing to the currently shorter ranges of affordable BEVs, you'll probably be doing it more often too. Which is why I think installing charging at workplaces and local parking lots, along with a switch to AV BEVs which can charge wirelessly, will be essential to make the large-scale switch I think is needed quickly, instead of over a half-century or more.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

smkettner
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Re: Toyota Mirai Fuel Cell

Mon Jul 09, 2018 7:54 pm

GetOffYourGas wrote:Of course, we are talking here about the occassional road trip. What we are missing is the elephant in the room - the daily commute. This is the bulk of most people's annual mileage. .....snip
Exactly this.

If you build all the infrastructure for fueling all cars as hydrogen it will be a huge undertaking. If you build infrastructure to charge EVs for long distance there is not any need for the same scale. 80%+ would be my guess that EVs would charge at home with less than 20% needed for long distance travel. You just do not need as much public infrastructure for an EV.
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mux
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Re: Toyota Mirai Fuel Cell

Mon Jul 09, 2018 10:18 pm

GRA wrote:You seem to be arguing against yourself. Yes, charging speed are increasing, something that's much needed if BEVs are to compete with ICEs for long trips. But why should that be necessary, if refueling speed doesn't matter?


In these really long comment chains the original context often seems to get lost. I'm arguing a systematic point: if refueling speed is the major USP of high-density fuels, then this is poised to become moot as charging speed and availability of DCQC stations increases. Right now, charging speed is still a weak point of contemporary EVs compared to gas, diesel or hydrogen, but this is going to be moot in a very short timespan as range on a single charge as well as QC speeds improve.

That's my actual point, and that is completely congruent with what I've said so far.

GetOffYourGas
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Re: Toyota Mirai Fuel Cell

Tue Jul 10, 2018 4:10 am

GRA wrote:
GetOffYourGas wrote:
jlv wrote:OK, I see that logic!

Of course, once you toss in the ability to DCFC at 350kW at a reasonable cost...

Of course, we are talking here about the occassional road trip. What we are missing is the elephant in the room - the daily commute. This is the bulk of most people's annual mileage. How much time do you save in a year by charging while sleeping or working (i.e. about 10 seconds/day to plug/unplug your car) versus travelling to the pump (gas or H2) once a week and standing there for 5 minutes while pumping fuel? I know it's a change in mindset, but I'll take the slightly longer road trip over the weekly fuel stop any day.

But going further, the last time I took a trip beyond my car's range, I simply timed my charge stop to coincide with a meal. So even my 40 minute charge session took considerably less time out of my trip than gassing up. If I had to buy gas, I would have eaten dinner and then had to go to the pump for 5 minutes to refuel.

All true, for those who can charge at home. For those who can't, which is currently most of the world's car-owing population, you have the same issue of time spent driving to/from the station, plus a much longer wait once you get there, and owing to the currently shorter ranges of affordable BEVs, you'll probably be doing it more often too. Which is why I think installing charging at workplaces and local parking lots, along with a switch to AV BEVs which can charge wirelessly, will be essential to make the large-scale switch I think is needed quickly, instead of over a half-century or more.


Yes, this is also true. The solution is to provide charging outlets where people are parked overnight, not to add more high-power chargers so they can continue the old MO. I know that will take a while, but I have to believe that adding L2 charging to street/lot parking spots would be cheaper than building a ton of H2 fueling stations. But that's just my gut. I haven't done the math - feel free to prove me wrong.

More to the topic, home fueling is the ace in the hole for EVs. It won't happen for H2 at any larger scale than the current hobbyist making bio diesel at home. In order to be competitive at all, FCVs will need a bigger battery and a plug, with an AER sufficient for a typical commute. But then that causes a downward pressure on demand for H2 fueling stations, which makes it even harder to build and operate one profitably. I'm in the camp that doesn't see FCVs ever working out as passenger cars. The Mirai only seems to confirm that.
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mux
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Re: Toyota Mirai Fuel Cell

Tue Jul 10, 2018 4:54 am

GetOffYourGas wrote:Yes, this is also true. The solution is to provide charging outlets where people are parked overnight, not to add more high-power chargers so they can continue the old MO. I know that will take a while, but I have to believe that adding L2 charging to street/lot parking spots would be cheaper than building a ton of H2 fueling stations. But that's just my gut. I haven't done the math - feel free to prove me wrong.


Most quantitative arguments never deal in these kinds of absolutes. It is essentially unprovable that the total cost, all said and done, of an equilibrium system of either kind will go one way or another. What's usually done, though, is that you either

1) work from the current day and extrapolate current trends for as much as they will reasonably stretch,
2) work from first principles (raw material cost, complexity arguments, energy cost) and reason your way towards a likely outcome

Moreover, these kinds of questions are then STILL almost impossible to answer considering most factors driving uptake will be political and social, not physical or financial. If oil companies tomorrow decide to go all-in on hydrogen fuel cells and subsidize the shit out of them (and they can - there's a couple dozen trillion dollars on the line that can be diverted, more than enough to litter the world with untold amounts of free hydrogen cars and fueling stations), skewing the calculation a lot.

If you want I can rattle off some raw numbers of hydrogen vs battery-electric charging infrastructure if you need context.

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RegGuheert
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Re: Toyota Mirai Fuel Cell

Tue Jul 10, 2018 4:18 pm

GRA wrote:And the higher throughput of the H2 stations means less land is required per car served.
Absolute nonsense. You conveniently ignore the fact that the vast majority of BEV refueling is done at the destination, requiring NO additional land.
RegGuheert
2011 Leaf SL Demo vehicle
10K miles: Apr 14, 2013, 20K miles (55.7Ah): Aug 7, 2014, 30K miles (52.0Ah): Dec 30, 2015, 40K miles (49.8Ah): Feb 8, 2017, 50K miles (47.2Ah): Dec 7, 2017.
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RegGuheert
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Re: Toyota Mirai Fuel Cell

Tue Jul 10, 2018 4:24 pm

mux wrote:Most quantitative arguments never deal in these kinds of absolutes. It is essentially unprovable that the total cost, all said and done, of an equilibrium system of either kind will go one way or another. What's usually done, though, is that you either

1) work from the current day and extrapolate current trends for as much as they will reasonably stretch,
2) work from first principles (raw material cost, complexity arguments, energy cost) and reason your way towards a likely outcome

Moreover, these kinds of questions are then STILL almost impossible to answer considering most factors driving uptake will be political and social, not physical or financial. If oil companies tomorrow decide to go all-in on hydrogen fuel cells and subsidize the shit out of them (and they can - there's a couple dozen trillion dollars on the line that can be diverted, more than enough to litter the world with untold amounts of free hydrogen cars and fueling stations), skewing the calculation a lot.

If you want I can rattle off some raw numbers of hydrogen vs battery-electric charging infrastructure if you need context.
What's missing in this discussion is that BEVs can actually pay back the cost of the infrastructure by lowering the cost of fuel, particularly when PV is providing the electricity. That is why many homeowners are willing to pay for the charging infrastructure to add BEVs into their fleet. With H2 gas, there is NO way to payback the cost, meaning that it is simply the government wasting the taxpayers' money.
RegGuheert
2011 Leaf SL Demo vehicle
10K miles: Apr 14, 2013, 20K miles (55.7Ah): Aug 7, 2014, 30K miles (52.0Ah): Dec 30, 2015, 40K miles (49.8Ah): Feb 8, 2017, 50K miles (47.2Ah): Dec 7, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

GRA
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Re: Toyota Mirai Fuel Cell

Tue Jul 10, 2018 5:16 pm

mux wrote:
GRA wrote:You seem to be arguing against yourself. Yes, charging speed are increasing, something that's much needed if BEVs are to compete with ICEs for long trips. But why should that be necessary, if refueling speed doesn't matter?


In these really long comment chains the original context often seems to get lost. I'm arguing a systematic point: if refueling speed is the major USP of high-density fuels, then this is poised to become moot as charging speed and availability of DCQC stations increases. Right now, charging speed is still a weak point of contemporary EVs compared to gas, diesel or hydrogen, but this is going to be moot in a very short timespan as range on a single charge as well as QC speeds improve.

That's my actual point, and that is completely congruent with what I've said so far.

We have no disagreement that charging speeds are increasing and must do so to be fully competitive with ICEs, the issue is at what point it will become moot, i.e. how close to ICE capability do charging speeds and range need to be to be considered generally acceptable to the public as a full ICE replacement. I don't believe 150kW is enough, 350-400 kW is closer and will satisfy many, but 900-1000kW (China's talking about 900kW for GB/T) would probably be necessary to render the discussion moot, as 6-7 minutes would give enough range to allow my 4 hour plus reserve freeway with HVAC replenishment, and that's probably close enough assuming every energy replenishment stop will at least include a bathroom break. The cost of the infrastructure necessary to provide anything approaching such rates is so far unknown. Such high-rate infrastructure can be limited to major road trip corridors, but will still be expensive.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

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