Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen • Hacker News Board

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

#381

Post by dkarras » Wed, May 19, 2021, 1:16 AM UTC

emptyfile wrote: post #277

SigmundA wrote: post #268

Earlier quoted context omitted.

Lithium batteries still seem to have a way to go in energy density currently at around 250-300 wh/kg and going up year over year with a theoretical maximum (Sulfur cathode) of above 2500 wh/kg. At around 2000 wh/kg you are equivalent to diesel drivetrain energy density both size and weight based on my rough math. Expensive large hydrogen tanks in a trailer with high pressure lines to tractor seems like it would cause…

I have no clue about batteries or hydrogen tanks. But I'm always amused to think that posters on HN give more credence to their back-of-the-napkin calculations over opinions of, say, folks at Toshiba, Volvo or Daimler.

You'll be surprised how much your predictions improve if you stop for a moment to do some back of the napkin calculations. Lots of overly optimistic or pessimistic news out there just to grab your attention. Having an edge in prediction and BS detection compared to the average Joe is an important life skill IMO.

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

#382

Post by walrus01 » Wed, May 19, 2021, 1:27 AM UTC

jacquesm wrote: post #230

FWIW: the material challenges for hydrogen are such that I do not think that it will ever be a mainstream storage medium for vehicular use (it's not a fuel, it is a battery). - hydrogen embrittlement - leakage from whatever container you plan to use - very low activation energy -> always danger of explosion So it's a great thing in the lab and to get subsidy for but it sucks for large scale deployment, and deploying…

I have to agree with you, because I've seen detailed instructions, schematics and photographs of the apparatus for refueling a hydrogen fuel cell based UAV. The pressures of the tanks involved and connectors, pipe and hose system do not look like something you would want millions of ordinary untrained end-user consumers attaching to vehicles. Everything needs to be perfectly clean and in pristine condition in order to be safe.

People already manage to start fires and cause disaster at gas stations doing something as simple as putting a nozzle into their car and filling it with 87 octane gasoline.

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

#383

Post by JimTheMan » Wed, May 19, 2021, 1:39 AM UTC

throwaway0a5e wrote: post #47

KMnO4 wrote: post #12

Since “tank” isn’t a unit of measure, I suppose anyone could trivially break the record with a larger tank. From the article: > The Nexo consumed 6.27kg of H2 For comparison with the other production H2 cars: Toyota Mirai: 5.6kg Honda Clarity: 5.0kg Seems like a promising technology. My understanding is that the current blocker is infrastructure. It’s hard to pressurize up to 10,000 PSI, so many facilities are only a…

10,000PSI hydraulics are rapidly becoming cookie cutter commodity parts. Once you have the supply chain for all the little crap that nickles and dimes you the rest is a lot cheaper. Having industry expertise at working at those pressures really has a huge multiplier effect on everything else. Building a system to plumb stuff from A to B at a pressure nobody uses is expensive. Calling up a sales rep and asking for sli…

Compressed liquid systems don't explode so much, they tend to be way less catastrophic as they are a liquid. (The burst, or they spray out fluid)

Gas compressed things EXPLODE, or things that become gas on de-pressure. 10,000 psi is an insane pressure to have in a tank. Gas transmission pipelines operate at 1450 psi...

It's not an apples and oranges comparison. In the O&G industry we default to hydrotesting over pneumatic testing in basically all situations.

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

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Post by ajross » Wed, May 19, 2021, 1:56 AM UTC

rootusrootus wrote: post #351

ajross wrote: post #257

Earlier quoted context omitted.

> Tesla is known for rigging its EPA tests for higher, but illusory, numbers. The Tesla numbers are correct and verifiable, actually. The problem is that the EPA "highway" test is designed to capture the "average highway mile" driven by a US vehicle (which makes sense, it was designed to inform purchasers of aggregate fuel use). Here's the driving schedule: https://www.epa.gov/sites/production/files/2015-10/hwfetdds.…

> The Tesla numbers are correct and verifiable There are caveats. The lower end Model 3s hit their estimates pretty reliably. The Performance trim usually misses by a pretty big margin for most people. There are exceptions to every rule, but I owned a P3D and hung out with other P3D owners as well, and this was a commonly shared experience.

I have to wonder how much of that is down to the way the driving habits of people who buy a car labeled "long range" differ from those who buy one that calls itself "performance". It doesn't really refute the notion that the difference between measured and claimed performance is due to the different driving conditions being tested.

IIRC there was some youtube video a year or two back that tested a few variants on a track using what they claimed to be a replica of the EPA highway test, and the cars came out almost dead on.

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

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Post by cmrdporcupine » Wed, May 19, 2021, 2:23 AM UTC

wglb wrote: post #359

WorldMaker wrote: post #305

Earlier quoted context omitted.

By a lot, mostly. The liquid hydrogen eventually doesn't have enough pressure/cold enough temperature to stay liquid so it turns back to gas and most bubbles out of the water (with some of it reacting with Oxygen and becoming more water). It's possible if it were a "big enough" and "concentrated enough" spill it might briefly create anoxic zones where fish will die. https://en.wikipedia.org/wiki/Anoxic_waters (But hu…

It is also a greenhouse gas http://agage.mit.edu/publications/global-environmental-impac...

"If a global hydrogen economy replaced the current fossil fuel-based energy system and exhibited a leakage rate of 1%, then it would produce a climate impact of 0.6% of the current fossil fuel based system. "

That doesn't sound so ... bad?

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

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Post by cmrdporcupine » Wed, May 19, 2021, 2:31 AM UTC

bdamm wrote: post #92

sandworm101 wrote: post #66

Earlier quoted context omitted.

It is, but it doesn't have to be. It is possible to make H2 from H20 and sunlight. At the moment there is little market for such "green" hydrogen but the hope is that hydrogen-based transportation will create that market. Imho I cannot afford to be a market leaders in this field. Until H2 is available everywhere, including at remote locations during Canadian winters, I'll have to stick to gas stations. (I have yet to…

While technically true, the conversion is inefficient. It takes a lot of power to extract H2 from H2O. You could just use that power directly. The problem with electrics in -50 is keeping them plugged in when not in use. -50 is very extreme though, you’re talking far north or Edmonton.

Apart from some freak events that happen every 50 years -50C doesn't _really_ happen anywhere settled in Canada. Even a place like Inuvik, the coldest temp ever recorded was -56.7C but only for a few minutes... in 1968. Edmonton gets a few nights where it can get below -40C every once in a while, but it's not common and again, it's not all night.

Frankly it just sounds like he's confusing actual temperature with wind chill "temperature". Which unfortunately seems like something more and more Canadians do, probably on account of crappy weather reporting.

I grew up in Edmonton area. People were already in the habit of plugging their (ICE) vehicles overnight on those kinds of evenings so they could start in the morning without hassle. I see no reason why an EV wouldn't be treated the same.

(FWIW I live in southern Ontario now, it doesn't really get colder than -28C. But my Chevy Volt has no problem with it.)

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

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Post by judge2020 » Wed, May 19, 2021, 3:02 AM UTC

_carbyau_ wrote: post #377

jfengel wrote: post #341

Earlier quoted context omitted.

At least you get a half hour to think about how you should have plugged it in last night.

For me that'd be half an hour to ruminate on how my apartment has no place to charge a car. I am not getting an EV anytime soon unfortunately.

The general lack of EVs in multifamily housing is concerning for EV adoption - the only places where it's really possible is if the community offers a garage and the site's willing to book an electrician to install the 240v outlet.

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

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Post by judge2020 » Wed, May 19, 2021, 3:15 AM UTC

Robotbeat wrote: post #107

jdblair wrote: post #31

Earlier quoted context omitted.

It depends on how you define convenient. Hydrogen can be refilled quickly, in minutes, like a conventional liquid fueled car. If there were a network of hydrogen filling stations then driving, especially long distances, would be similar to driving a liquid fueled car.

Right. Similar to a liquid fueled car, but worse than an electric car in most circumstances. But the problem is there will never be an equivalent hydrogen network as there is gasoline network because hydrogen fueling stations are far more expensive to install and maintain. Either the station overhead ends up much higher than gasoline or hydrogen is used much more rarely. Electric car distance records as of 2018 are 1…

I thought it sounded expensive hearing that Tesla's high-powered superchargers cost hundreds of thousands of dollars[0], but apparently hydrogen stations can cost north of 2 million dollars[1].

0: https://techcrunch.com/2013/07/26/inside-teslas-supercharger...

1: https://www.wardsauto.com/technology/costs-check-growth-fuel...

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

#389

Post by samplatt » Wed, May 19, 2021, 3:31 AM UTC

abakker wrote: post #380

semi-extrinsic wrote: post #366

Earlier quoted context omitted.

Nope, because you don't make hydrogen tanks out of materials that are susceptible to hydrogen embrittlement. In particular, pressurized automotive-size hydrogen tanks aren't made from metal at all, they are typically epoxy/kevlar/carbon fiber composites.

OOC, since you know what these tanks are made out of, what is the duty cycle/lifespan of those tanks? I was presented some info on Kevlar tanks for drones using fuel cells and remember thinking that the lifespan was very short.

Anything bound by epoxy (or any polymer?) surely will have a comparably short lifespan...

Re: Hyundai Nexo sets new world record 887.5 km travelled on single tank of hydrogen

#390

Post by rootusrootus » Wed, May 19, 2021, 3:44 AM UTC

ajross wrote: post #384

rootusrootus wrote: post #351

Earlier quoted context omitted.

> The Tesla numbers are correct and verifiable There are caveats. The lower end Model 3s hit their estimates pretty reliably. The Performance trim usually misses by a pretty big margin for most people. There are exceptions to every rule, but I owned a P3D and hung out with other P3D owners as well, and this was a commonly shared experience.

I have to wonder how much of that is down to the way the driving habits of people who buy a car labeled "long range" differ from those who buy one that calls itself "performance". It doesn't really refute the notion that the difference between measured and claimed performance is due to the different driving conditions being tested. IIRC there was some youtube video a year or two back that tested a few variants on a t…

AFAIK, Tesla uses the same range estimate for all trim levels of the Model 3 (or did in 2019, at least). The problem is that the Performance trim has 20 inch non-aero wheels and sticky tires. I got 325+ Wh/mi steady state cruise on the highway using AP to do the driving (in good weather; was 350+ when colder).

There have been some independent tests and IIRC the consensus is that the standard range Model 3 was rated pretty accurately, and the Performance trim was rated something like 25-30 miles too high compared to reality.