Bill Gates just bought a $645M super yacht powered by liquid hydrogen | Hacker News Reader

Bill Gates just bought a $645M super yacht powered by liquid hydrogen

esquireme.com

9 pointswslh8 comments

It's funny to say "100% green", since in this particular case you need also to look how much pollution was made in the building process of a yacht, and if the price pays off with it being 100% green.

Or where the hydrogen comes from (currently the huge majority of commercial hydrogen originates from fossil fuels)

Things might have changed, but back in the days they usually just flared off hydrogen sulfide because it was hard to deal with and not very profitable. You more or less had to force the oil companies to collect it.

So yes - often a byproduct of oil production, but if the oil companies had it their way, they'd burn it on the spot.

> However, despite the rumours of a Gates investment, the Aqua is still just a concept.

I think this makes the title misleading: we're not even sure that he invested in a boat that does not exist yet.

> a $645 million 100% green luxury super yacht

> meaning that its only emission will be water

Production by-products aside, hydrogen production is majorly the processing of fossil fuel[^1], which rejects carbon monoxide. Introducing the boat as 100% green is misleading.

[^1]: https://en.m.wikipedia.org/wiki/Hydrogen_production

Ok, so as far as I can tell this is just a concept.

"Liquid hydrogen" I guess makes for some splashy headlines but I'm doubtful about the practicality. Hydrogen boils at -253C (20K). This is not a trivially achieved and maintained temperature.

NASA used this for the Saturn V, which largely explains why the Saturn V is still the most powerful rocket ever flown. To compare:

- Liquid hydrogen + liquid oxygen has a specific impulse of 450

- SpaceX's Merlin engine uses RP-1 (kerosene) and liquid oxygen for a specific impulse of 250-300

The demands of the Falcon 9 are lower of course (not exceeding geostationary orbit, for a second ignoring the Falcon Heavy variant) but this affords SpaceX the luxury of using a fuel that is much cheaper to store and use.

This goes beyond cold however. Hydrogen atoms are incredibly small (fun fact: helium atoms are smaller). This makes leakage a huge problem. It also gets in between the atoms of whatever storage material you're using (for fusion reactors this problem is called "helium embrittlement").

So do I believe this will turn into something real? Let's just say I have my doubts.

So this is a super yacht that can sail to Cannes. Or the moon. Awesome!

At the end of the article, it says “However, despite the rumours of a Gates investment, the Aqua is still just a concept.” It’s unclear what exactly is the truth.

Came here to quote that. Rumors? This article is garbage.

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