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.
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 should alway try to understand the math / science and make your own judgements rather to falling for arguments from authority. This isn't always feasible but I think most people can do enough to weed out the snake oil to a much better degree than we seem to be doing as a society now.
Note this will also make you a better engineer / programmer in my experience.
For instance the Semi being announced in 2017 I said no way, but their range numbers where not outlandish, they just conveniently left off weight numbers for the tractor and cost of the battery seemed to high at the time. What I missed was how quickly battery cost are coming down and energy density going up, however they still haven't delivered a tractor yet so...
Tesla has a real tech lead, not sure if they can keep it and they are way over valued stock wise.
Nikola complete BS.
H2 offered the highest ISP, ie energy per fuel mass, and originally they wanted the Shuttle to be a single stage to orbit vehicle. But Hydrogen also added larger, much heavier tanks and engines didn’t have enough thrust for that. So they had to add large Solid Rocket Boosters to get off the pad. And all they additional dry mass meant the higher ISP of H2 was wasted.
And now the SLS is repeating those mistakes, not because engineers didn’t learn those lessons, but because politicians require them to repeat them.
Engineers recommending Hydrogen for cars are influenced by regulatory requirements and benefits, and politically by company objectives. If your CEO says Hydrogen is important to use because our government and regulators say it is, you as an engineer will find a way to make the best of a bad choice.
They also have large resources and are willing to experiment in things (especially if there are incentives around it from government, etc) - and even if it fails entirely they'll likely get useful and actionable data and results that still can help the company.
Which umm shows you never know who’s posting here.
The Emperor and the downtrodden, the Ivey League and the community college, you'll find the same mathematics wherever you go.
Some may have an advantage in innovation or inspiration, but it should he fair trivial for any sufficiently motivated individual to check the numbers.