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Comment by charliea0 | Hacker News Reader

I feel like commercial fusion is such a lost cause at this point. For electrical generation, it’s going to have high fixed costs which will likely make it uneconomical for the same reasons fission struggles. The cost of fuel already very low for traditional fission and renewables.

I don’t see what advantages it would have over wind, solar, fission, etc.

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That’s because commercial fusion doesn’t exist yet. All new technology isn’t commercially viable when only viewed from the perspective of early prototypes.

This is as equally true for consumer hardware as it is for massive scientific endeavours.

Many (most?) novel technologies never become commercially viable. I think what @charlieao is saying is that they suspect fusion will be one of the failures. That's a different claim from the one you're countering.

Of course predicting the future of new tech is always a kind of bet. I don't know enough about the details to make a judgement either way. Fairly obviously it just isn't going to be ready in time for the thing it's most often touted for - ie. the decarbonisation exigency. That's just the usual research funding opportunism.

But assuming we do make it over the next few decades (very unlikely in my view), cheap limitless energy is inevitably going to be transformational.

Usually those novel technologies that don’t become viable is because it’s either a technology we don’t want (like a sentient toaster) or there is another technology that can solve the same problem but cheaper.

In the case of fusion, it’s something we do want (fission and burning fuels aren’t sustainable indefinitely) and as our energy needs increase year on year, the cost for energy will also increase if we don’t find a way to supply that demand. This makes a mass producer of clean energy more viable.

Renewable energy is great but it’s not exactly cheap to scale either. In fact the only reason it has gotten so cheap is precisely because the need for it has lead to plenty of advancements that have also driven down the cost.

So fusion in this form of reactor might prove to be a dead end but at some point humanity will end up with some form of fusion. Even if it’s not in our life time. And assuming we haven’t had an extinction event first…

> Usually those novel technologies that don’t become viable is because it’s either a technology we don’t want (like a sentient toaster) or there is another technology that can solve the same problem but cheaper.

I'm sure there must be academic studies looking into reasons for tech not getting to production. I don't know them, so I can only hazard a guess that this isn't quite right. I think many technologies just don't prove feasible outside the lab. One cause of infeasability is of course price (no route found to a true industrial scale learning curve). But sometimes it's safety or inherent limitations that weren't understood before trying to scale, or any number of other causes not predictable from basic science. You can't know 'till you know, and for fusion, we don't know yet. It's a bet (which to be fair is the same with nearly any new tech). A good one, perhaps.

it's not that simple. context (timing, culture/politics, market conditions, regulations) is very important.

there's a lot of interest nowadays in "progress studies" which tries to tackle this (or a very similar set of) questions

yes, sure commercial fusion is definitely one of the toughest nuts, but fission based small modular plants are viable, yet it's barely being done. and there are many products and technologies that are economical yet not widespread. (let's say public transport.)

Agree on the complexities. 'Viability' has to be conceived more widely than just a technical sense. Fission a good example, as you suggest. A dead duck in most of the world. As is wide-scale decarbonisation! We know that (a) it is technically feasible, and (b) it is politically infeasible. So decarbonisation is actually not viable, despite appearing technically possible from a narrow perspective.

This also makes commercail fusion very unlikely to happen in this civilisational iteration. It requires large advanced economies with highly functional and specialised supply chains. These conditions won't exist once climate refugees sweep the world in their billions, and wars break out everywhere. If, indeed, given Russia/Ukraine, and the joint determination of China & the US to go to war, we even last that long.

Just running the steam turbine part of a power plant struggles to compete with renewables. I don't see how attaching a complicated high-tech gizmo to the steam engine can help the economics unless it also prints money as a side effect to producing heat.

The problem with natural gas turbine is the energy cost of fuel. One looses a lot extracting it from Earth. And then there are unknown, and, as such, potentially catastrophic, consequences of pumping more and more CO2 into the atmosphere.

Fusion reactors has none of that. But the cost of gizmos as seen currently is a way too high indeed.

>Just running the steam turbine part of a power plant struggles to compete with renewables.

Disingenuous. Your bicycle costs less than a car, but can you use it to move 500 pounds at 60 mph in the rain? Talk about renewables + seasonable storage.

Fusion is a high-capex form of energy. If your only niche in the market is the two windstill, dark weeks in the year you'll have a hard time recouping your investments.

This is the worst kind of handwave that signals complete lack of interest and understanding is energy economics.

Sorry for not writing scientific papers in the HN comment box, but note that you handwaved in just the same manner.

Compare commercial fusion to commercial quantum computing - the latter looks far more real than the former.

It is the opposite, https://www.researchgate.net/publication/359947675_Will_We_E...

But then one still has to be skeptical about tokamaks. Plasma instabilities for unknown reasons alone is enough for that.

And then there is the flux of energetic neutrons with order of magnitude higher energies than that of a fission reactor. Spherical tokamaks are especially bad in that respect as the central thin handle cannot be protected sufficiently.

At least with stellarator designs there are no instabilities and the neutron flux can be managed with a sufficiently thick blanket, so those are safer bets than tokamaks.

But they also need to be larger for a given power output, so frontrunners are trying tokamaks first because if they can get those to work at reactor relevant levels then they will have a cheaper / more competitive product. If tokamaks don't work out and the price of electricity is sufficiently high, then stellarators will likely make the most sense.

They're not even sure tokamaks can be run steady-state and not pulsed. That's hand-waved as an "engineering problem" like everything else tokamak-related. Stellarators at least look like they could, since you don't need to induce a current to generate the magnetic field via induction.

Pulsed reactors is not a showstopper. If you pulse heat into a coolant blanket there is plenty of thermal energy buffer. Hitting 90+% duty cycle is an engineering challenge with no physics hurdles.

Fission is theoretically amazing in many cases, but is hampered by branding problems. If fusion can be marketed as "clean", it gets a comparative advantage.

As I understand it, fusion's radioactive contamination and waste is a lot shorter-lived than fission reactors', and there's no chance of a runaway meltdown reaction (not that there's any chance of that with a modern fission reactor either... and fission reactors generate a tiny bit of waste in exchange for free unlimited energy...)

Cleansion.

That's one of the points of the spherical tokamaks - they're MUCH smaller than the standard tokamaks (I can't remember the numbers but it's vastly smaller). That brings the cost way way down. The modern HTS magnets are also more powerful, even in the Tokamak systems (like CFSs) which again get the size way down - I think it's something like cubed size reduction for doubling magnet strength (?). You'd be right for something of the silly size of ITER.

It doesnt have to be cheaper, the bar is set somewhere around 'lets not fuck up this planet more than we need' level, price is secondary.

A lot of renewables require massive amount of energy, raw materials and pollution to get done, and then last decade or two at best. I have yet to see a bigger wind turbines fields who are all fully working at given time, usually mote than half doesnt move even in stronger winds due to ie maintenance

The cost of materials may be low for fission but convincing people to have a nuclear powerplant near there homes and engineering it to be safe are not.

Fusion on the other hand has no chance of a run away meltdown and the materials that are used are much easier to dispose of.

We can make fission reactors now that have no chance of run away meltdown. Good luck convincing the public to live next to one anyway. I don't expect Average Joe is going to be willing to differentiate between fission and fusion in that regard.

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