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Hydrogen powered cargo ships have already been made as well. However, I'm not sure if hydrogen generation on board ships has been explored yet. Who knows... it may be possible for ships to run without ever needing to refuel if generation is done on board.

Sorry. Go back and study thermodynamics again. If you have the energy to generate hydrogen, you might as well use that energy to move the ship. You're always going to spend more energy generating the hydrogen than you will get back burning it or combining it in a fuel cell. The one exception is if you start from just the right feedstock to generate the hydrogen from, like some hydrocarbon. The leading candidate now is natural gas. However, in that case, the byproduct is CO2 -- so what's the point?

Or, maybe you were thinking of hydrogen as energy storage? Batteries are far better than hydrogen as far as that goes.

Yeah, you're probably right... generation on board ship doesn't make much sense. Unless the ship is stopped for some time I guess.

Storage for hydrogen can be really large, in the TWh size. Because they can use natural gas storage tanks. There's nothing that big for batteries. The big Tesla solar installation on that Samoa island was six megawatt hours, with 60 battery packs.

Energy generation is not a problem, there is nuclear, sun, wind. Energy storage is. Currently, hydrogen should be a better option for energy storage as it is cheaper than the expensive and explosive lithium-ion batteries. Never mind that lithium-ion loses its capacity on every cycle and requires rare minerals.

> Also Hydrogen vehicles are a thing now.

I'm going to have to disagree with you there. Electric cars are absolutely a thing; if you pay close attention you will spot a decent number of them in a day's worth of driving. Dedicated supercharging infrastructure is already fairly widespread, and basic wall electricity is already everywhere and is available as a second resort.

So sure, hydrogen cars themselves may exist, but the infrastructure does not, and I'm not aware of many people who reasonably expect that it ever will exist. Electric cars seem to have already won in the competition of "what renewable will replace gas".

Where I am, the only electric cars I see are car sharing vehicles. Maybe a Volt or a Model S every few months. I do see a good deal of Toyota hybrids and maybe a Lexus every week or so, but those are still burning fossil fuels.

Where are you? I've seen lots of electric vehicles in SF, DC, MD, and NYC.

Europe. :-) But even when I went to Florida on vacation last year I only saw a couple Teslas in three weeks.

For sure EV are a thing, and I don't think they are going away. But I don't think they'll be the only game in town.

There are quite a few hydrogen cars driving around in Japan, and infrastructure there is almost rolled out. For cars only Toyota is starting to roll them out in California. Some are starting to be sold around Europe as well. I think they've only sold around 700 in the USA.

Natural gas pipeline and storage infrastructure can be used. Because an order of magnitude more gas can be stored as hydrogen, than in lithium batteries I think they will be in the mix.

I definitely think it's a better idea for larger vehicles like trains on lines which aren't electrified.

It remains to be seen whether those are mass produced cars or just test market cars that Toyota produces just enough to get their eco-friendly credits. Toyota made cars just so they can claim they fill the quota in the past.

Has the storage problem of hydrogen been solved? I thought that a) most containers leak hydrogen, and b) hydrogen makes (most) containers brittle over time?

Or do these new trains use some kind of (electric) hydrogen fuel cell, that doesn't work like traditional combustion?

Toyota seems to be the only ones able to do it in small vehicles well. Whereas it seems to be much easier in larger vehicles, since many more companies are bringing big vehicles to market. They use lithium batteries with the hydrogen charging the lithium batteries. I guess this is why Toyota is doing well - since they have lots of experience with hybrid vehicles.

If you're just going to burn hydrogen in a fuel cell to generate electricity, why even bother? Why not skip the middleman and use all-electricity to start with? The only possible advantage I see hydrogen having here is quicker fill-up times, but that comes at the cost of many other downsides, the worst being lack of existing infrastructure and reduced efficiency.

The current Toyota car being sold can go 312 miles per 'tank', and takes 5 minutes to refuel. Which is better than Tesla EV cars.

It's much easier for trains, and larger vehicles to bring the infrastructure online. Existing natural gas pipeline and storage infrastructure can be used. Probably only a big company like Toyota could pull off getting the infrastructure in place for car sized vehicles. So far they have only done Japan, and parts of California.

I've seen TWh storage being quoted. Which is quite a lot higher than battery systems. Sure, if you can use the electricity directly, there is no need for storage. However, if you need to store a lot of energy, and you need the ability to send it around then gas isn't so bad.

Time will tell if it all works out I guess. But from the systems selling now, it seems like it's now viable.

It's actually very convenient to store it in water.

RIP Stan Meyer.

Hydrogen has a few problems:

the storage - you need very high pressure tanks to store them, and while this can be done, this is not cheap and easy

the inefficiency of creating and storing the hydrogen. When you compress a gas a lot of energy is lost by the heat produced by the compression.

So a hydrogen fuel cell vehicle will be 3x less efficient in electricity consumption than a battery electrical vehicle.

For the German trains, luckily there is plenty of hydrogen that is a waste product of existing chemical industry in Germany. In many places there is extra power from wind, solar, and hydro which is wasted when production is too high. So the idea is to use this excess power for hydrogen production.

Additionally hydrogen can use the existing natural gas pipeline infrastructure.

In times of high wind, there can be enough energy to power all of Europe/Japan in a few days. New types of turbines need to be put into production that can actually use this however. Current ones are shut down so they are not damaged. So far I'm only aware of prototypes, but it's being worked on.