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Comment by kmeisthax | Hacker News Reader

To be clear, NIF's ignition is getting more energy out of the fuel than the laser they hit it with put in, but there are other energy drains and inefficiencies in the system that make it nowhere close to break-even fusion energy. That requires building a new machine designed for continuous fusion detonations.

So it's a scientific accomplishment, but not that scientific accomplishment.

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Whenever anyone brings this up, it's important to remind everyone this is the best in the world to this day, so every time people (namely, people invested in MCF or various private companies) shit talk NIF understand they are saying their schemes per the data are even worse than what is apparently a bad result.

I question your assumption that most people who bring this up are people invested in MCF or various private companies.

I think for most people, the question isn't between this fusion and that fusion, it's about fusion and anything else.

We haven't yet been able to get useable energy out of fusion. It may be wonderful if we could, but at the moment, every dollar spent on fusion is a dollar not spent on building more solar panels and wind turbines.

If it really is the case that it will not be possible to power the world without fusion, then that might be money well invested, but it's quite possible that we should just be putting everything into existing renewable technologies.

>It may be wonderful if we could, but at the moment, every dollar spent on fusion is a dollar not spent on building more solar panels and wind turbines.

You care to back your armchairing with data? I'll bet you 100usd that it's a pittance compared to what goes into solar and wind turbines world wide. This point is not salient.

>I think for most people, the question isn't between this fusion and that fusion, it's about fusion and anything else.

That's a more valid point. The point for ICF is the potential, this is a sure push in the direction of "this actually has potential," justifying more research, not that we'll have a power plant in 5 years. There isn't this antagonism towards other aspirational research like superconductors or quantum computers.

>> every dollar spent on fusion is a dollar not spent on building more solar panels and wind turbines.

> You care to back your armchairing with data?

I'm confused by your confusion. I'm literally saying we could optionally be spending the money we currently spend on fusion on solar panels instead. This isn't a statement that needs data.

The question is simply which is going to go further in decarbonizing our energy: $1 spent on solar or $1 spent on fusion research?

That's an open question, of course, and people don't have the answer, since one is based on probabilities of future success.

Note, though, that even if fusion is successful, it may still be more expensive than solar, and so then would it actually be successful? We would have saved more tons of CO2 by making more solar panels. [1] [2] [3]

1. https://www.wired.com/story/no-fusion-energy-wont-be-limitle...

2. https://futurism.com/elon-musk-fusion-more-expensive-wind-so...

3. https://engineering.princeton.edu/news/2023/03/16/fusions-fu...

> I'm literally saying we could optionally be spending the money we currently spend on fusion on solar panels instead. This isn't a statement that needs data.

We can’t. Who is picking between fusion research and 7% IRR solar projects? Two totally different risk profiles.

> We would have saved more tons of CO2 by making more solar panels.

If that’s your sole metric it’s probably worth thinking a little broader towards a solution. I don’t think Mohammed bin Salman is going to cap Ghawar Field because we put up a bunch of solar panels over here. He’s going to sell to somebody else.

I think it’s better to let the market work towards solutions that compete across all dimensions—density included—and let that drive the energy transition.

So the question is, what is a better energy infrastructure investment—definitely spending a dollar on fusion research, or not spending that dollar on fusion research and instead maybe, in theory, spending it on solar panels. I’ll take the good plan now vs the maybe a better plan later option.

"Solar vs. Fusion" isn't really important as long as trillions of $/€/£/... are sunk into fossil fuel extraction and use ?

There's plenty to reaearch in Solar Panels still as well - Perovskite is hot now, but other material systems, engineering optimisation, inverter efficiencies, BIPV, non-Li-Ion battery systems, all these and then some are actively researched and developed right now. And not all of that will productise. Yet, move money off fossil subsidies to those first ... and only after bash nuclear, whether fission or fusion.

Even if fusion is the energy source of the future and will always be that - fossil fuels are that of the past. They shall be, or remain, buried. This really isn't about renewable vs. renewable.

Comparing basic science research with commercial product research is comparing apples with oranges.

Governments spend research money on space research, particle accelerator, fusion research, basic medical research, and similar that do not intend to turn a profit. National Institutes of Health for example spends more on basic medical research than all of industry combined. The health industry takes that research and uses it to develop products, which combined R&D are several times that of the budget of NiH. $1 of NiH basic medical research is not the same as $1 R&D by a medical company, and especially not the same as $1 going into production. Spending $1 to produce a pill may save a life. $1 of NiH basic medical research may save a population.

We could but it’s a short sighted perspective. It’s like telling someone working on the steam engine to stop spending money because we could buy so many horses instead.

Every dollar we put into fusion could also go into all sorts of things that have nothing to do with renewable energy.

For government funding, the money could go to small fission reactors, some military project unrelated to energy, or just a reduction in the deficit.

For private investment, the sort of investors interested in fusion breakthroughs would probably go for other high-risk, high-reward opportunities rather than switching to a mature industry.

> at the moment, every dollar spent on fusion is a dollar not spent on building more solar panels and wind turbines

You are of course technically correct ("the best way to be correct"), but let's be honest: figuring out the optimal allocation of resources between solar/wind/geothermal and fusion research is unsolved problem. It's probably outright unsolvable.

It's also not a problem of one or the other. We will need both.

Remember that fusion research is not just about fusion. The materials technology advances are almost certainly going to show up elsewhere in various forms. To top it off, the nature of the technology itself requires that a non-trivial fraction of the funds are directed towards fundamental research. We can not know, or even guesstimate where those results end up being used outside of fusion research tracks.

I will not be surprised at all if/when some research done for advancing fusion will be used to improve solar and wind technologies.

> It may be wonderful if we could, but at the moment, every dollar spent on fusion is a dollar not spent on building more solar panels and wind turbines.

That's not how this works. The money that goes to research is very far removed from the money that goes towards utilities' capital investments. To say nothing of the politics involved.

Regardless, we stand to gain more than just a possible energy source from this research.

>“ It may be wonderful if we could, but at the moment, every dollar spent on fusion is a dollar not spent on building more solar panels and wind turbines.”

Every dollar spent on cars and transistors is a dollar not spent buying more horses and vacuum tubes

People shit talk NIF because it's a very expensive machine to calibrate the Fortran code used to test hydrogen bombs without detonating them, in no way meant to advance fusion for power generation, that gets accolades for doing something that will probably not be useful for a useful advance in fusion.

Indeed, in the laser business, during a time period when it seemed like someone was coming up with a new kind of laser every month, the field developed a term, "wall plug efficiency," which meant how much laser power per unit of power drawn from the electrical outlet. It was meant to capture the true energy efficiency of the system, rather than just the efficiency of the lasing process.

“Energy drains and inefficiencies” underplays it. The laser they’re using is, what, 10% efficient? So they’re at least an order of magnitude away from net power. Probably two orders.

0.5% efficient, but they're old lasers. Equivalent modern ones are over 20% efficient.

Also, with their first Q>1 shot they increased the laser power 8% and got 230% more output. They think the nonlinear scaling will continue for a while. If they're right, then they're not actually that far from overall net power, if you correct for the obsolete laser tech.

And they don't have any mechanism to capture the generated energy and convert it to electricity.

What are the chances that will be anything other than the tried and true "boil some water to make steam to turn a turbine"

Fusion produces helium, you fill party balloons with it, they lift an anvil which falls on a pair of scissors that cuts a piece of string in half...

The Incredible Fusion Machine

Phew!

This is like saying "burning gasoline produces CO2, how do you make energy with that?" Literally the quoted energy they use to calculate the ignition criterion for NIF is the neutron yield.

It’s also like saying, “This is kind of an amusing joke for those that enjoy amusing jokes”.

That's exactly what it would be, for any fusion that's not using aneutronic fuel.

That literally is it, just like fission you capture neutrons and heat water. The engineering issue of getting a stream of pellets to shoot is the issue, the "how do you convert neutrons from DT into electricity" just betrays severe ignorance. The engineering issue is a bigger jump.

The issue of capturing power out of the exploding pellet is not at all the same as the issue of capturing neutrons out of a MCF reactor, and neither is the same as the problem of capturing the neutrons from a fission power plant.

The neutrons from fusion reactos are far more powerful, so they punch much more easily through materials you put in the way. Also, the ICF reactor has many moving parts (the pellet needs to be put in a very precise position for the lasers to shoot), so transferring heat from it is not nearly as easy as a much simpler fission reactor (which is mostly just a hunk of uranium which stays hot, and all the complexity comes out of being able to prevent the uranium from getting too hot).

When I first learned how nuclear reactors actually generate power it was a big WTF moment for me. Wait - do they really just heat water? For some reason I thought that there was a more advanced process to extract electricity from the reactor.

Yup. It does seem inefficient.

I assume the cost is “good enough”.

In Back to The Future, Doc Brown not only invented a time machine, but a device that fits into a Delorean that can directly convert plutonium into electricity.

This was announced back in 2008, but it sounds like it didn't go anywhere:

https://www.newscientist.com/article/dn13545-nanomaterial-tu...

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