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→‎How much would be needed, if hydrogen were scaled up?
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(Refactored page. But the PGMs section still needs redoing.)
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{{minor|Note: It ''is'' possible to build fuel cells and electrolysis systems without PGMs, but the energy-efficiency is much lower.{{qn}} There are scientists trying to overcome this,<sup>[LINKS needed]</sup> but there's no guarantee that it will be viable in the near future.}}
{{minor|Note: It ''is'' possible to build fuel cells and electrolysis systems without PGMs, but the energy-efficiency is much lower.{{qn}} There are scientists trying to overcome this,<sup>[LINKS needed]</sup> but there's no guarantee that it will be viable in the near future.}}


====How much would be needed, if hydrogen were scaled up?====
===How much would be needed, if hydrogen were scaled up?===
<tab name="General principles" collapsed>
{{minor|The mass of PGMs needed is proportional to ''peak power'':}}
* For electrolysis systems, the maximum '''rate of hydrogen production''' {{light|is limited by the amount of PGMs}}.
* For fuel cell vehicles, the '''horsepower''' {{light|is limited by the amount of PGMs}}.
** {{minor|But the vehicle can still achieve ''short bursts'' of higher horsepower if there's a battery or supercapacitor in parallel with the fuel cell.}}
</tab>
 
<!-- --- DATA POINTS --- -->
<!-- --- DATA POINTS --- -->
{{dp
{{dp
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|<nowiki>pgm.mine_production</nowiki>
|<nowiki>pgm.mine_production</nowiki>
|<nowiki>platinum.mine_production + palladium.mine_production</nowiki>
|<nowiki>platinum.mine_production + palladium.mine_production</nowiki>
|<nowiki>Global production of platinum-group metals (PGMs) from mining</nowiki>
|<nowiki>Global production of platinum-group metals (PGMs) from mining (status quo)</nowiki>
|<nowiki>Assumption: that the other PGMs (iridium, rhodium, osmium, ruthenium) are in such small quantities that it's ok that they aren't counted here (because data is unavailable)</nowiki>
|<nowiki>Assumption: that the other PGMs (iridium, rhodium, osmium, ruthenium) are in such small quantities that it's ok that they aren't counted here (because data is unavailable)</nowiki>
}}
}}
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|<nowiki>pgm.reserves</nowiki>
|<nowiki>pgm.reserves</nowiki>
|<nowiki>70000 tonnes</nowiki>
|<nowiki>70000 tonnes</nowiki>
|<nowiki>Global reserves of platinum-group metals</nowiki>
|<nowiki>Global mineral reserves of platinum-group metals</nowiki>
|<nowiki>Includes platinum, palladium, ruthenium, rhodium, osmium, iridium.</nowiki><br /><nowiki>
|<nowiki>Includes platinum, palladium, ruthenium, rhodium, osmium, iridium.</nowiki><br /><nowiki>
</nowiki><br /><nowiki>
</nowiki><br /><nowiki>
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}}
}}
{{dp
{{dp
|<nowiki>fossil_fuels.energy</nowiki>
|<nowiki>fossil_fuels.consumption</nowiki>
|<nowiki>11596.92 Mtoe/year</nowiki>
|<nowiki>11596.92 Mtoe/year</nowiki>
|<nowiki>Total consumption of coal, oil, and natural gas (worldwide)</nowiki>
|<nowiki>Total consumption of coal, oil, and natural gas (worldwide) (energy units)</nowiki>
|<nowiki>Key World Energy Statistics 2020 (IEA report)</nowiki><br /><nowiki>
|<nowiki>Key World Energy Statistics 2020 (IEA report)</nowiki><br /><nowiki>
- page 47: World energy balance, 2018</nowiki><br /><nowiki>
- page 47: World energy balance, 2018</nowiki><br /><nowiki>
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|2
|2
|
|
|Without this, we'd be calculating for just personal vehicles. But we also need to factor in commercial vehicles such as buses and trucks. These vary widely in size, and data is hard to find, so for simplicity sake, we just assume that they'd add up to about the same as personal vehicles - thus doubling total energy storage needed. This assumption is based on the fact that freight trucks are a somewhat smaller share of [[energy demand]] than passenger vehicles, but the trucks probably need a longer range.
|Without this, we'd be calculating for just personal vehicles. But we also need to factor in commercial vehicles such as buses and trucks. These vary widely in size, and data is hard to find, so for simplicity sake, we just assume that they'd add up to about the same as personal vehicles - thus doubling total energy storage needed. This assumption is based on the fact that freight trucks are a somewhat smaller share of [[energy demand]] than passenger vehicles, but the trucks need far more horsepower and probably a longer range.
}}
}}
<!-- --- END OF DATA POINTS --- -->
<!-- --- END OF DATA POINTS ---
-->
<tab name="General principles" collapsed>
The supply of PGMs is limited to what we can mine from the Earth (mineral reserves / resources), so we have to be mindful of how much would be needed.


<tabs><tab name="Estimate #1">
{{minor|The mass of PGMs needed is proportional to ''peak power'':}}
Suppose,
* For electrolysis systems, the maximum '''rate of hydrogen production''' {{light|is limited by the amount of PGMs}}.
* that all of today's [[energy demand]] were to be met using hydrogen gas
* For fuel cell vehicles, the '''horsepower''' {{light|is limited by the amount of PGMs}}.
* that all hydrogen gas were to be produced using [[wind]] power (or something with the same [[capacity factor]] as wind)
** {{minor|But the vehicle can still achieve ''short bursts'' of higher horsepower if there's a battery or supercapacitor in parallel with the fuel cell.}}
* that all PGMs can forever be recovered and recycled
</tab>


'''Tl;dr: There ''are'' enough PGM minerals in the Earth, but today's mining rates would be ''far too slow''.'''<br />
<small>We'd have to start mining a lot faster, and find some way to do it '''without''' exploitative [[labor]]. {{en}}</small>


'''Calculations:'''
'''Scenario 1:''' If hydrogen gas (from wind power) were to directly replace all fossil fuels (this implies that people would drive [[hydrogen combustion vehicles]]):
<tab name="(see maths)">
{{calc
{{calc
|energy.tfc / wind.capacity_factor * electrolysis.pgm_by_power
|electrolysis.pgm_by_power / electrolysis.efficiency / wind.capacity_factor * fossil_fuels.consumption
|grams per capita * world.population
|% pgm.reserves
|production_pgm
|a
|PGMs needed for hydrogen production:
}}
}}
{{calc
{{calc
|world.cars * toyota_mirai.pgm
|a
|grams per capita * world.population
|years pgm.mine_production
|consumption_pgm
|PGMs needed for hydrogen-based electricity consumption:
}}
}}
</tab>
In other words, the amount of PGMs needed is pretty reasonable - but we'd have to start mining a lot faster than the status quo (and find some way to do it '''without''' exploitative [[labor]]).{{npn}}
And in fact, some{{x|about half, if calculated from the same datapoints used on this page}} of this mining could be avoided, as we could also recycle existing catalytic converters{{x|which also contain ''some'' PGMs, though nowhere near as much as fuel cell vehicles}} from the gasoline cars and diesel trucks that would no-longer be used.


{{calc
|world.cars * catalytic_converter.pgm
|grams per capita * world.population
|recyclable_pgm
|PGMs recoverable from catalytic converters of old gas cars:{{minor|Old semi trucks (not counted here) could also provide a bit more}}</small>
}}


'''Scenario 2:''' If all vehicles were hydrogen [[fuel cell vehicles]] instead:
<tab name="(see maths)">
{{calc
{{calc
|production_pgm + consumption_pgm - recyclable_pgm
|(toyota_mirai.pgm - catalytic_converter.pgm) * world.cars * commercial_factor
|% pgm.reserves
|% pgm.reserves
|
|b
|Compared to mineral reserves:
}}
}}
{{calc
{{calc
|production_pgm + consumption_pgm - recyclable_pgm
|b
|years pgm.mine_production
|years pgm.mine_production
|
|Compared to current production rate:
}}
}}
</tab>
<!-- TALK:
Maybe I should refactor [[template:calc]] to allow for presenting one calculation in multiple units? This would involve some design decisions.
-->
One benefit of fuel cell vehicles is that they're more energy-efficient than combustion vehicles (i.e. less hydrogen used per kilometer driven).


This estimate is imperfect and oversimplified, but probably reasonable in a scenario where some vehicles use hydrogen combustion and some use fuel cells. In general,
The problem is, fuel cells would need 7 times the PGMs of Scenario 1 {{light(in the estimate above)}}. Perhaps too much to be scalable. And this is true even though we factored in the recycling of old catalytic converters this time (which have less than 1/10th the PGMs of a hydrogen fuel cell vehicle, on average).
* If more vehicles use hydrogen combustion, we'd need more wind power but less PGM.
* If more vehicles use fuel cells, we'd need less wind power but more PGM.


In any case, producing that much wind power is maybe reasonable if most farmland were to be covered in wind turbines.
{{calc
|energy.tfc / wind.capacity_factor * wind.rq_land
|% crop_land
}}


'''Verdict:'''
* If we're going to have hydrogen-powered vehicles, most of them will probably have to be combustion only (or some sort of hybrid with just a very small fuel cell).
* PGMs are ''not'' a limiting factor for wind-based hydrogen ''production''.
<tab name="More discussion / research needed">
<div style="font-size:70%;color:#333;margin:1em;border:1px dashed #CCC">
<div style="font-size:70%;color:#333;margin:1em;border:1px dashed #CCC">
More musings about the calculations above:
More musings about the calculations above:
* Hydrogen ''combustion'' vehicles are about as energy-efficient as gasoline combustion vehicles. But hydrogen ''fuel cell'' vehicles are more efficient. We'd need '''less''' hydrogen than this estimate calls for.
* All of this assumes that electrolyzers and fuel cells can be completely recycled at their end-of-life, with all PGMs recovered. If they can't, we're kind of screwed in the long run (at least for hydrogen).
* Home electricity would be done with fuel cells too. We'd need '''more''' PGMs than this estimate. We'd need '''more''' hydrogen than this estimate, to make up for the losses in fuel cells (although those losses could be used as [[heating]] in some cases).
* Hydrogen ''combustion'' vehicles are about as energy-efficient as gasoline combustion vehicles. Hence we can assume that the Scenario 1 estimate is accurate enough.
* If electric [[semi trucks]] use fuel cells too, we'd need '''more''' PGMs than this estimate.
* Home electricity can also be done with fuel cells - this would of course need more PGMs (and more hydrogen to make up for the losses in fuel cells (although those losses could be used as [[heating]] in some cases)).
* Or if a large enough percent of all vehicles use combustion instead of fuel cells, then we'd need '''less''' PGM than this estimate.
* We didn't count the hydrogen needed in the vehicles that transport the hydrogen (hopefully would be minor, like with fossil fuel transport).
* We didn't count the hydrogen needed in the vehicles that transport the hydrogen (hopefully would be minor, like with fossil fuel transport).</small>
* All this is based on status-quo energy demand, which unfortunately relies on the fact that most of the world currently lives in poverty. If all nations were developed, more resources would be needed.
* All this is based on status-quo energy demand, which relies on the fact that most of the world currently lives in poverty. If all nations were developed, a lot more resources would be needed.
* Wind power land estimates are based on status-quo installations which are likely on windier-than-average land. In which case, maybe crop land wouldn't be enough - but then again, there's also pasture and barren land that could be used.
* But in any case, we probably wouldn't actually use wind/hydrogen for everything anyway. [[Rooftop solar]] combined with [[the great battery challenge|batteries]] could probably be a better way to provide electricity whenever hydrogen need not be involved.
* But in any case, we probably wouldn't actually use wind/hydrogen for everything anyway. [[Rooftop solar]] combined with [[the great battery challenge|batteries]] could probably be a better way to provide electricity whenever hydrogen need not be involved.
* Since vehicle fuel cells use the biggest share of PGMs in this estimate, this is yet another reason to advocate for [[public transit]] and [[walkability]].
* Since vehicle fuel cells use the biggest share of PGMs in this estimate, this is yet another reason to advocate for [[public transit]] and [[walkability]].
</div></tab></tabs>
</div></tab>




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