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Re:Rivian S-1 by jazzyjackson on Saturday October 02, 2021 @01:40AM (#28726247)
I like hydrogen. The idea that every personal vehicle should have 1000 pounds of lithium-cobalt-etc is crazy to me, that's before getting into super-trucks and 18 wheelers, then not to mention aircraft and cargo ships.

Batteries are neat, but I'm not sure they scale.

Re:Rivian S-1 by coryrc on Saturday October 02, 2021 @02:58AM (#28726590)
Modern vehicle weigh multiple tons, what's a half-ton battery really matter?

Also much of the weight is carbon and oxygen. LiFePO4 also (obviously) is substantially iron and phosphorous.

Li-Ion battery production had been growing at double-digit percentage for decades. I think they've proven you wrong many times over.

Finally, electric cars charge at ~96% efficiency, while hydrogen is something like 40%. I, for one, am not interested in paying 3x per mile.

Re:Rivian S-1 by rewma on Saturday October 02, 2021 @03:58AM (#28726874)
> Modern vehicle weigh multiple tons, what's a half-ton battery really matter?

The Tesla Model S weights about 2100kg.

The Tesla Model S battery weights about 540kg.

This means that a 1500kg car is forced to pack an additional 540kg to be able to store energy. That's an additional 30% of the mass that you need to accelerate and brake.

People do care about that. In the very least, the battery mass is responsible for an effective drop in energy efficiency of around 30% just to cart someone around.

> Finally, electric cars charge at ~96% efficiency, while hydrogen is something like 40%. I, for one, am not interested in paying 3x per mile.

This claim has little substance and credibility. For starters, if you factor in how much additional energy you need to waste just to pack along a massive half ton battery, you'll eventually realize that the effective energy waste of a EV is not much different than the hydrogen one.

I mean, the point of a EV is not to have it parked on the driveway, charge a battery, and proceed to boast about how that was very efficient. Your goal is to move around, and moving that massive half ton beast of a battery along with you wastes a lot of energy too.

Also, battery efficiency is around 80%, which naively sounds a far improvement over fuel cell's lauded 40% efficiency. However, a Li-Ion battery weights half a ton and represents around 1/3 of a EV's mass, which also requires energy to be moved around. For reference the fuel cell of a Toyota Mirai is only 40kg, less than the weight of an adult passenger. Once you do your math you'll quickly notice the effective energy use is not that different.

And then there's the cost argument. The typical back-of-the-napkin figure for how much EVs cost to run is around 500€/year. Even if you bump that up to twice the cost, that price is eclipsed by the huge markup that you're already paying for an EV. I mean, a Tesla Model S costs about a century worth of energy bills before it even gets it's tires dirty.

Playing the frugality card with the current batch of EVs lacks any credibility and is, at best, being penny wise and pound foolish.

Re:Rivian S-1 by bostik on Saturday October 02, 2021 @06:59AM (#28727603)
> This means that a 1500kg car is forced to pack an additional 540kg to be able to store energy.

I think this is the wrong angle to look at the issue.

A 2100kg EV requires 25% of its total mass to support the energy storage, generation and transfer in order to provide a range and performance profile people are generally happy with.

What is the fraction for a new ICE vehicle with similar profile? The combustion engine weighs... how much? Then add the weight of a 60% full fuel tank to allow for roughly the average deadweight haul between refills. Then include the weight of the exhaust system.

And finally, we have to include the weight of the drivetrain. How much of the total weight in an ICE is dedicated to power transfer from engine to wheels? How much in a modern EV?

Energy storage and generation is only a part of the picture, getting it to the wheels is what makes a car actually perform its function. We should include these numbers to get a meaningful comparison.

Re:Rivian S-1 by JProthero on Saturday October 02, 2021 @07:41AM (#28727798)
> Finally, electric cars charge at ~96% efficiency, while hydrogen is something like 40%.

>> This claim has little substance and credibility.

The efficiency of hydrogen fuel cell vehicles versus battery vehicles is considered in some detail in this video [1]. The conclusion [2] is that, in the best case, the energy efficiency from power generation to road for existing or near future hydrogen fuel cell vehicles is about 25%, compared to about 65% for typical existing battery vehicles.

[1] https://www.youtube.com/watch?v=f7MzFfuNOtY

[2] https://www.youtube.com/watch?t=651&v=f7MzFfuNOtY

Re:Rivian S-1 by IshKebab on Saturday October 02, 2021 @07:18AM (#28727689)
> In the very least, the battery mass is responsible for an effective drop in energy efficiency of around 30% just to cart someone around.

It's not nearly as simple as that because electric cars have regenerative braking, and because the energy doesn't all go into acceleration. A lot (probably most, depending on how you drive) goes into wind/rolling resistance at a constant speed and that doesn't depend much on mass.

Re:Rivian S-1 by glogla on Saturday October 02, 2021 @10:00AM (#28728613)
Toyota H2V (Mirai) has a small battery that serves as a buffer for the fuel cell, and it can also regen brake into it.

I'm still convinced hydrogen is scam greenwashing natural gas, though.

Re:Rivian S-1 by adgjlsfhk1 on Saturday October 02, 2021 @11:31AM (#28729386)
Note that regenerative breaking means that extra mass doesn't actually cost you much in terms of fuel use.
Re:Rivian S-1 by jazzyjackson on Saturday October 02, 2021 @04:44AM (#28727093)
> Li-Ion battery production had been growing at double-digit percentage for decades. I think they've proven you wrong many times over

Mold in a petri dish grows at an accelerating rate, until it doesn’t

My conjecture is that there’s not enough lithium/etc in the world to store the energy the transportation sector requires

small cars, passenger trains, sure. but freight is a different animal. we’ll see.

Re:Rivian S-1 by Tuna-Fish on Saturday October 02, 2021 @07:33AM (#28727770)
It's not a good idea to conjecture and argue from total ignorance. There are commonly used battery chemistries, such as LiFePO4/graphite, that simply do not use any scarce resources.
Re:Rivian S-1 by theduder99 on Saturday October 02, 2021 @09:01AM (#28728241)
welcome to hackernews. also why don't the car battery manufacturers go the lifepo4/graphite route?
Re:Rivian S-1 by mastax on Saturday October 02, 2021 @10:11AM (#28728698)
They do. Everyone in China is using them. Tesla is starting to use them outside of China as well.
Re:Rivian S-1 by Tuna-Fish on Saturday October 02, 2021 @10:07AM (#28728665)
Other materials are mildly better and not too scarce. Tesla is moving some of it's production to LFP, but that's probably mostly because they want to scale up production faster than nickel mining can scale.
Re:Rivian S-1 by lukeschlather on Saturday October 02, 2021 @10:58AM (#28729066)
Lithium is not a scarce resource. This is pretty obvious because when looking at commodity prices lithium is measured in $/metric ton rather than actually scarce elements like gold where the price is in $/troy ounce.
Re:Rivian S-1 by simondotau on Saturday October 02, 2021 @10:50AM (#28728994)
> The idea that every personal vehicle should have 1000 pounds of lithium-cobalt-etc is crazy to me

Whether it seems crazy is evidence of unfamiliarity, not whether it is actually crazy. Is it really any crazier that continually pumping every car with juice made from literal fossils?

At least the battery is continually reusable — and at the end of its useful life, over 90% recyclable.

Re:Rivian S-1 by swman on Saturday October 02, 2021 @12:56PM (#28730125)
What happens to the lithium and other metals? I don’t know much about this stuff so I’d appreciate to know
Re:Rivian S-1 by tantony on Saturday October 02, 2021 @03:29PM (#28731292)
They can be almost 100% reused. In fact, given how valuable the metals are it would be cheaper to do so than mine for them . There are multiple companies working on this. E.g. https://www.redwoodmaterials.com/
Re:Rivian S-1 by devoutsalsa on Saturday October 02, 2021 @02:33AM (#28726474)
I was hoping we’d just make synthetic gasoline from atmospheric carbon dioxide. Wouldn’t require changing any infrastructure at all. Just make gibs of it using renewables. It sounds good in theory anyway.
Re:Rivian S-1 by moonchrome on Saturday October 02, 2021 @03:11AM (#28726651)
One of the nice aspects of electric cars is going to be eliminating city polution and reducing road noise.

I have no idea what the CO2 impact would be and don't really care that much ("cutting CO2 will reset the climate to some state we like" sounds like wishful thinking and most of the talk in this space is ideologically coloured I don't even want to pay attention) but the improvement in urban living is going to be undeniable.

Re:Rivian S-1 by cesarb on Saturday October 02, 2021 @10:17AM (#28728739)
> but the improvement in urban living is going to be undeniable.

When the pandemic arrived here back in March 2020, and nearly everyone suddenly stopped leaving their home, it was eerie: the air where I live (in the middle of a major urban area) suddenly smelled as if I was in a rural area. It was something I wasn't expecting to see so soon; I have for a long time been rooting for EVs to arrive and make the air quality better, but unfortunately EVs are simply way too expensive yet (so far, I only have seen an EV once, and it was an i3 with a range extender; and I do live in a major metropolitan area).

Re:Rivian S-1 by jazzyjackson on Saturday October 02, 2021 @04:39AM (#28727074)
aside from accelerating at stoplights, electric cars and gas cars make similar noise levels just from the rubber against the road. rubber is a significant pollutant as well, as is brake dust.

Don’t get me wrong, electric is much better, i’m only nitpicking since you said “eliminating”

Re:Rivian S-1 by moonchrome on Saturday October 02, 2021 @05:01AM (#28727170)
Brake dust is much less of an issue with electrics too, but agreed that tires are still a factor. But as someone who lived in urban centers for the majority of his life - I think getting down to tires being the major issue is solving the majority of the problem.
Re:Rivian S-1 by cesarb on Saturday October 02, 2021 @10:18AM (#28728745)
> aside from accelerating at stoplights, electric cars and gas cars make similar noise levels just from the rubber against the road.

There's also the idle engine rumbling noise while waiting at stoplights, which does not exist on electric cars.

Re:Rivian S-1 by m4rtink on Saturday October 02, 2021 @04:28AM (#28727012)
That would still not solve all the localised polution caused by burning it in cars.