Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Launch HN: Maritime Fusion (YC W25) – Fusion Reactors for Ships

news.ycombinator.com

Post reply on HN
Print view View original

201–210 of 267 posts

Re: Launch HN: Maritime Fusion (YC W25) – Fusion Reactors for Ships

#201

Post by defrost »

nocoiner wrote: post #164
FiatLuxDave wrote: post #139

Greybeard former fusion founder here. Wishing you guys all the luck in the world! Email in profile in case you wish to chat. For all the naysayers, as a fusion startup, targeting the marine market is a good move. They aren't even the first fusion startup to do so; IIRC Rostoker's group got their first major funding from the NRL. The marine market pays a premium for not having to refuel, and historically emerging ener…

Can you elaborate on the use of photovoltaics in shipping? After a few searches, I haven’t been able to find anything that suggests the marine industry was an important sector for its development. Also, I feel extremely confident predicting that the commercial maritime industry will never ever pay a premium for a particular fuel source. There may eventually be some applications where fusion is most efficient, but fus…

Addendum:

I should have addressed this in my peer comment, from the Launch HN header above

  Why ships? They don’t have great alternatives—the shipping industry is desperate to decarbonize. Hydrogen and ammonia are being explored, but come with serious downsides: low energy density, flammability, leaks, and massive infrastructure challenges.
Is a bit odd from my PoV as it skipped over methanol .. the "green" fuel of choice in shipping today, with supply contracts already inked and signed, ships built, and more in pipeline.

DNV GL welcomes Lindanger to fleet – world’s first methanol fuelled ocean-going vessel (2016)

  “We are very pleased to see the completion and launch of this exciting and innovative newbuilding,” says Knut Ørbeck-Nilssen, CEO at DNV GL – Maritime.

  “This is the first time a dual-fuel engine with a Low Flashpoint Liquid (LFL) fuel system has been installed on an ocean-going vessel and it is a testament to the excellent cooperation between all the project partners that we have been able to complete this unique project and gain flag state approval. Methanol as a marine fuel is a very promising option to enable owners to reduce the environmental impact of their vessels and to comply with low sulphur and ECA regulations and we look forward to working on many more projects using this innovative marine fuel and technology.”
~ https://www.dnv.com/news/dnv-gl-welcomes-lindanger-to-fleet-...

Methanol as fuel heads for the mainstream in shipping (2023) - https://www.dnv.com/expert-story/maritime-impact/Methanol-as...

Also - https://www.methanol.org/marine-fuel/ and https://www.methanex.com/about-methanol/marine-fuel/

Re: Launch HN: Maritime Fusion (YC W25) – Fusion Reactors for Ships

#202

Post by kelseydh »

dust42 wrote: post #54
phtrivier wrote: post #40

> and we believe we’ll witness Q > 1 within a few (say 3) years. That’s huge. I think it fits squarely in the "requires extraordinary evidence" bucket - what makes you so bold ? Also, what's you intermediate plans between : 2025 -> Post on HN 2028 -> Q>1 achieved (by you ? by someone else ?) ???? -> ???? 20xx -> a ship goes to sea powered by a fusion reactor ???? -> ???? 2060 -> fusion is so easy, let's use it for ba…

Also, what's you intermediate plans between : 2025 -> Post on HN 2028 -> Q>1 achieved (by you ? by someone else ?) CFS plans Q>1 for 2027 with a tokamak design. If they succeed then there will be plenty of VC for similar designs. I'd place my bets that CFS succeeds with Q>1. And I think the real problem will be the energy flux and neutron handling and thus much more a material sciences problem than a plasma physics p…

Is that QPlasma>1 or QTotal>1?

Re: Launch HN: Maritime Fusion (YC W25) – Fusion Reactors for Ships

#203

Post by Earw0rm »

joss82 wrote: post #197
usrusr wrote: post #129

Earlier quoted context omitted.

Let's be realistic, it would have a diesel engine as a plan B. But if you like sails: my pet hypothetical technology is wind-driven hydrogen tankers (or tankers for some other e-fuel derived from hydrogen) that sail out empty, then cruise around wherever there is plenty of wind. They'd have a turbine/generator setup driven by the water passing by and use the energy harvested there for filling the tank. Cruise around…

Interesting concept. Let's run the numbers... The largest Q-Max-class gas tanker is 345 meters long [1]. Let's say you manage to fit 3 giant Siemens wind turbines on it, with 100m long blades [2]. It's a bit cramped but let's say you have extenders on the side to make room for all 3 of them. And also let's say you found a way to prevent the ship from tipping over when the wind is strong. By deploying floaters on the…

It strikes me that having the turbine and hydrolysis plant fixed in place, and having ships visit those sites to refuel, is probably an easier setup than mobile turbines.

But I think your maths is wrong somewhere. Hydrogen supplies 33MWh/tonne, and you've stated the ship capacity as 18620 tonnes. 18620/(33*24) gives a generation time of 23 days, even before we allow for hydrolysis overheads.

Marine hydrogen isn't a terrible idea though. Tank weight and bulk is prohibitive for aviation, but less so for shipping.

Re: Launch HN: Maritime Fusion (YC W25) – Fusion Reactors for Ships

#204

Post by sandworm101 »

rnhmjoj wrote: post #195
pclmulqdq wrote: post #153

Earlier quoted context omitted.

Aren't the products of fusion equally radioactive? I get that we all have the idea of helium being the main product, but don't you get a lot of tritium out of the process? It's not quite proliferation, but it's not non-radioactive either.

Yes, tritium is radioactive but it has to be recycled and reused to continuously fuel the reactor. Every part of a fusion reactor is designed to minimise the retention of tritium, the actual radioactive waste will be materials activated by neutron radiation (neutrons are captured by nuclei, transmute the element into a radioactive one which then decays to a stable isotope emitting more radiation). A small fusion reac…

Which is why in "fusion" bombs the majority of energy still comes from fission. The fusion reaction is a neutron source to boost the efficiency of the fission reaction. A pure fusion bomb, if one could ever trigger such a thing without fission, would not be very efficient.

Re: Launch HN: Maritime Fusion (YC W25) – Fusion Reactors for Ships

#205

Post by nworno »

tim333 wrote: post #198
nworno wrote: post #196

Don't understand how that could have somehow been vetted by a YC committee. I mean I'm all in for fusion power, but so far it remains in the state of utterly edge-case research project into which governments all over the world have been pouring insane amounts of money in the hope for the holly grail of energy. And you are spawning a private company that is discussing the nitty-gritty details of applying that non-exis…

Helion Energy ( https://news.ycombinator.com/item?id=8178450 ) has been going 11 years and building prototypes and raising many millions by saying power is 5 years away or so and not publishing any results. So I guess that model works sort of. Currently "Helion claims it will build the world’s first nuclear fusion power plant by 2028 and has already secured a purchase agreement from Microsoft." but Sabine is sceptica…

Interesting yes, but regardless of the scientific viability of Helion's approach (that I have no means to discuss), at least they are aiming at addressing the core problem of fusion energy as an investment strategy: turning an non-existent into an existent technology. What bewilders me here are people discussing the business model and implementation details of these ships' reactors for the endeavor to become profitable. These kind of discussions would only be appropriate in the Worldbuilding StackExchange.

Re: Launch HN: Maritime Fusion (YC W25) – Fusion Reactors for Ships

#206

Post by usrusr »

joss82 wrote: post #197
usrusr wrote: post #129

Earlier quoted context omitted.

Let's be realistic, it would have a diesel engine as a plan B. But if you like sails: my pet hypothetical technology is wind-driven hydrogen tankers (or tankers for some other e-fuel derived from hydrogen) that sail out empty, then cruise around wherever there is plenty of wind. They'd have a turbine/generator setup driven by the water passing by and use the energy harvested there for filling the tank. Cruise around…

Interesting concept. Let's run the numbers... The largest Q-Max-class gas tanker is 345 meters long [1]. Let's say you manage to fit 3 giant Siemens wind turbines on it, with 100m long blades [2]. It's a bit cramped but let's say you have extenders on the side to make room for all 3 of them. And also let's say you found a way to prevent the ship from tipping over when the wind is strong. By deploying floaters on the…

You have it reverse wind turbines need mooring, stay upright and so on. That's highly impractical. No, you build a fast-going sail vessel (using big traction kites, because it's not the 19th century anymore) and power the generator from much smaller turbine blades in the water. Hydrogenerator is the term established in recreational boating.

I sure would not expect any returns in days, more like months or years. But if we (humanity) could just solve the purely man-made problem of piracy (or would it technically be salvage?), I believe that a robotic fleet of cruising hydrogenerators could be a huge contribution to our energy needs.

Re: Launch HN: Maritime Fusion (YC W25) – Fusion Reactors for Ships

#207

Post by phtrivier »

AtlasBarfed wrote: post #161
phtrivier wrote: post #40

> and we believe we’ll witness Q > 1 within a few (say 3) years. That’s huge. I think it fits squarely in the "requires extraordinary evidence" bucket - what makes you so bold ? Also, what's you intermediate plans between : 2025 -> Post on HN 2028 -> Q>1 achieved (by you ? by someone else ?) ???? -> ???? 20xx -> a ship goes to sea powered by a fusion reactor ???? -> ???? 2060 -> fusion is so easy, let's use it for ba…

Batteries are steadily improving, at least in the cost factor. We haven't seen any 2x leaps in density from sulfur or solid state or aluminum air. But LFP and Sodium Ion are making undeniable progress in cheap usable EV batteries that don't require nickel or cobalt.

> cheap usable EV batteries

I know this is going to sound harsh, but I will personnally consider EV batteries "cheap" only when they pass the very scientific "my mom can use the EV exactly like shes uses her car, and she does not notice" test:

* on one charge, drive 10-50km daily for 350 days in a year

* on one charge, drive 1000km in one go for the holidays

* it must be less than 10kE at a local car dealership

* it can be plugged in your garage

* if you forgot to charge it, you can stop every 10km to recharge in 10m

I know: "it's harsh" ! "We should change our car usage" ! "My mom should live differently to accomodate the technology", etc... Go tell that to my mom.

Still, that's the goal post I've been having for 20y, and 10y ago people where writing headlines about "breakthroughs" that would make this possible any time now. And it's not. So I'm burnt out, kinda.

Re: Launch HN: Maritime Fusion (YC W25) – Fusion Reactors for Ships

#208

Post by dredmorbius »

Nuclear fission is far more tractable than fusion, highly proven in marine transport, well-suited to workloads (boiling water -> electical generation -> propulsion), and yet still has proved nonviable not only in commercial shipping (Soviet/Russian icebreakers excepted), but in military transport other than submarines and, for the US and France, aircraft carriers. Even in those use-cases, most militaries with submarine fleets have no nuclear subs, and those which do often have few; only the US, Russia, UK, France, China, and India operate any nuclear submarines. Only the US and France operate nuclear carriers, with the latter operating only one such (China has one under development).

The US commissioned several nuclear cruisers, with a total of 9 achieving active status, though the last of these, the USS South Carolina, was decommissioned in July 1999.

Even given military (rather than commercial) considerations, the ships were too costly to operate and maintain.

There were a total of three non-Soviet commercial nuclear vessels, the American NS Savannah, and two ships launched by Germany (Otto Hahn) and Japan (Mutsu) respectively. Dating from the late 1950s to early 1970s, none proved economically viable, all faced major regulatory hurdles, being excluded from most ports and requiring extensive negotiations where they were permitted to berth at all, and all three were either converted to conventional powerplants or decommissioned entirely well before designed end-of-life.

As of 2023 China has designed, but not built, a thorium-based molten salt reactor (MSR) 24000 TEU cargo ship, a new development since I'd last looked at the space. More:

https://en.wikipedia.org/wiki/Nuclear_marine_propulsion#Civi...>

Looking into the matter of nuclear-powered shipping about a decade ago, I was struck by the relative small count (about 80k vessels then, since expanded to about 100k), and the frequency of hull losses, roughly 200 or so per decade. This suggests both scale issues and significant safety concerns, whether for fission-based or fusion-based propulsion, which despite a far smaller radiation footprint still has concerns with fusion reactor radioactive contamination, particularly on heavily-travelled sea lanes which tend to concentrate near population centres and fisheries, and thus significant environmental considerations, likely leading to severe regulatory restrictions. The tendency of shipping standards to be a race-to-the-bottom (figuratively and literally) given various minimal-requirements "flags of convenience" registries makes the probability that a nuclear fleet would have dodgey standards and/or find itself excluded from most ports (and commercially attractive ones most especially) also bodes poorly for prospects likely extending out decades even with unprecedented technological developments in the area.

Maritime Fusion strikes me as not only a very long shot but one with pretty limited prospects overall.

Re: Launch HN: Maritime Fusion (YC W25) – Fusion Reactors for Ships

#209

Post by dredmorbius »

nocoiner wrote: post #164
FiatLuxDave wrote: post #139

Greybeard former fusion founder here. Wishing you guys all the luck in the world! Email in profile in case you wish to chat. For all the naysayers, as a fusion startup, targeting the marine market is a good move. They aren't even the first fusion startup to do so; IIRC Rostoker's group got their first major funding from the NRL. The marine market pays a premium for not having to refuel, and historically emerging ener…

Can you elaborate on the use of photovoltaics in shipping? After a few searches, I haven’t been able to find anything that suggests the marine industry was an important sector for its development. Also, I feel extremely confident predicting that the commercial maritime industry will never ever pay a premium for a particular fuel source. There may eventually be some applications where fusion is most efficient, but fus…

PV energy capability per unit surface area is low enough that it's impractical for large-scale propulsion.

Marine PV has seen use on pleasure craft (particularly sailboats) for auxiliary power needs (electronics, nav, lighting, pumps, light cooking/heating), and for drone craft (there was a startup out of Alameda, CA, producing what seemed to be aimed as US Naval marine survey craft a few years ago, largely wind-powered but with electronics and back-up propulsion powered by solar arrays, see: https://newatlas.com/marine/72-ft-autonomous-saildrone-map-s...>.

Wind-capture remains the most viable alternative to fuel-based marine transport, and "windjammers" remained in commercial operation through the 1950s particularly on very-long-haul routes, though ultimately even that niche was captured by oil-powered propulsion. See: https://omeka2.hrvh.org/exhibits/show/a-new-age-of-sail/last...>.

Containerisation probably accelerated and/or solidified that decline as this permitted not only far more efficient loading and unloading, but requires clear decks and permits vastly larger ships and concommitantly greater crew efficiencies (crewing is almost entirely independent of ship size and capacity, so a larger and faster ship (factors which also trend together given hull speed and its relationship to length) is virtually always vastly more efficient than a smaller one, despite possibly greater total fuel consumption. Fuel use itself per unit cargo is also lower for larger shipping.

Current ship-size constraints are largely determined by harbour and canal dimensions (hence ship dimensions defined by max, e.g., Panamax, Suezmax, Chinamax, Batimax (Baltic Sea, not Baltimore Harbour), etc. I'm fond of the designation "Handy Size", which calls to mind "fun sized" though I'm told there's little relation. Maximum length capable of sustaining large seas (waves) without keel breakage is another marine engineering consideration which has limited ships to ~1,200 ft / 660m maximum length. At larger sizes ships are simply too susceptible to coming apart in heavy conditions.

Ships in general are constrained by the smallest viable dimensions of a port of call or route, and larger ships have fewer viable available ports or routes, though the busiest of such tend also to favour larger hull dimensions.

https://en.wikipedia.org/wiki/Cargo_ship#Size_categories>

https://en.wikipedia.org/wiki/Handysize>

Re: Launch HN: Maritime Fusion (YC W25) – Fusion Reactors for Ships

#210

Post by simne »

buildsjets wrote: post #33

If you are fantasizing the implementation of an imaginary future technology, why not fusion power for SPACE ships?

Because nobody predict so large grow of space industry, which could make fusion profitable.

Second problem, for space weight is so expensive, that it made fission viable, and solve proliferation problem (very little risk, somebody will steal materials from Moon or beyond).

Post reply on HN