[rewma]

> So, they have "ground breaking tech" in a dead-end technology then? The energy losses required to power vehicles with hydrogen are much greater than losses with electric batteries (there was a recent article on HN that really drove this point home for me).

These comments show a failure to understand what does hydrogen mean and why did it popped up as an alternative to ICEs to begin with.

Hydrogen is presented as an alternative energy store that is clean, renewable, and can leverage existing infrastructure and, perhaps more importantly, consumer patterns and mental models, with little to no change.

Energy efficiency is not a concern with hydrogen, or even a relevant talking point, because the promise of being able to generate it through renewable sources means it has no implication on its carbon footprint or even pollution. Also, it was a topic that was actively being researched and thus, much like photovoltaic panels, its efficiency was likely to go up.

We also need to keep in mind that hydrogen was closest to production and mass adoption a few years ago, and we need to remind ourselves that not so long ago the idea of widespread supercharger stations and affordable electric batteries with enough storage to power a small family car was very close to a pipe dream.

In my opinion, the only reason hydrogen why hydrogen hasn't been mass adopted was the colossal investment in marketing and R&D that a few private companies made in electric vehicles in general and Li-Ion batteries in particular. In the future we might very well look back at hydrogen in a similar way that a few years ago, when ICEs were the only game in town, we looked at the EVs from the late 19th/early 20th century and we wondered why were we so close but still missed the boat.

[grey-area]

Energy efficiency is important relative to other distribution methods. If the efficiency is half that of electric, you can power half the cars you could with electric with existing energy supplies. Obviously that is incredibly important - energy supplies will always be finite and fully utilised.

A few places have tried to build a hydrogen network with. Metal embrittlement is a real problem and storage is not straightforward, even after you've produced it.

https://electricrevs.com/2019/06/11/recent-explosions-shutdo...

Hydrogen hasn't been adopted because it is expensive, dangerous, difficult to store and not as efficient as electric. With advances in batteries in the last few years it is definitely on the way out and electric is the clear winner here.

[rewma]

> Energy efficiency is important relative to other distribution methods.

The point is that energy efficiency is only one factor among all other. For example, it makes little difference if you blindly tag a 80% efficiency tag on a EV if afterwards you have to waste twice the energy to cart along a massive battery.

> If the efficiency is half that of electric, you can power half the cars you could with electric with existing energy supplies.

The point that you're missing is that said cars are also far heavier (the battery on a Tesla Model S weighs half a ton alone which contrasts with Toyota Mirai's 40kg fuel cell), which requires far more energy to move around. What matters is how much energy you actually waste while driving, because that's where all the energy is going.

> Hydrogen hasn't been adopted because it is expensive, dangerous, difficult to store and not as efficient as electric.

I disagree with any of those points, specially as some of them like the safety scaremongering are far-fetched, as they aren't really grounded on the real world.

The critical difference between EVs and hydrogen was that EVs benefitted from a fantastic marketing and PR push, investment in infrastructure and R&D effort from private companies pushing EVs that was able to budge the status quo and made them acceptable to the public in spite of their major drawbacks such as massive cost, autonomy restrictions, and long charging times.

This foot-in-the-door was further compounded by the way some states decided to invest heavily in EV subsidies and public infrastructure, which was completely absurd, unrealistic and politically impossible in the recent past.

EV's recent mass adoption acceptance is not a technical feat but a social and political one which happened to leverage a specific technology.

[glogla]

Not sure where youre getting those numbers.

I'm not sure about Tesla, but according to specs I found, but Kia e-Niro with 400 km range is 1737 kilograms, 400 km range Hyundai Kona Electric is 1685, 500 km range WV ID3 is 1730 ... while Toyota Mirai is 1825 kg and my ICE Jaguar is 1950 kg.

Long story short, I'm not convinced it's so simple.

[glogla]

Energy efficiency is a major concern when you need literally three times the energy to achieve the same goal. Clen energy is already scarce, only places with a lot of nuclear have a semblance of it. BEV would already increase electricity demand a lot (grab vehicle-miles per year and turn it to TWh needed and see), doubling or tripling that would put the goal of decarbonization decades further away.

[KaiserPro]

can you name the sustainable sources of hydrogen, and their efficiency?

[rewma]

> can you name the sustainable sources of hydrogen, and their efficiency?

Hydrogen is an energy store. It doesn't typically exist by itself in nature and must be produced.

Thus the answer for your question is any and all renewable energy sources.

https://www.energy.gov/eere/articles/hydrogen-clean-flexible...

Neither electricity nor pre-charged Li-Ion batteries exist in nature by themselves, thus it's precisely the same problem.

[KaiserPro]

> Hydrogen is an energy store. It doesn't typically exist by itself in nature and must be produced.

I know hence the question.

to answer my question, which is also in the article you've kindly posted:

"Currently, most hydrogen is produced from fossil fuels, specifically natural gas"

Which is the point I'm getting at. Its cheaper to split natural gas than it is to do electrolysis.

What I have discovered is that state of the art electrolysis is about 80% which is far higher than I had remembered. Alas, fuel cells are still 40-60% efficient, so we could still be looking at terrible round trip efficiency.

Hydrogen might one day be the storage medium of choice, but its not yet. I suspect we'll have working fusion before we have practical grid scale hydrogen, let alone wide scale hydrogen cars.

[slownews45]

But the losses going from electricity -> hydrogen (and then back), and then losses again in failing to recaputure energy into hydrogen on board - I mean, you will need to use a lot MORE "renewable" energy to get your hydrogen vehicle around.