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

Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

imperial.ac.uk

Post reply on HN
Print view View original

281–290 of 494 posts

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#281

Post by tsimionescu »

gene-h wrote: post #238
tsimionescu wrote: post #105

Earlier quoted context omitted.

> Once it becomes self sustaining one should be able to add more fuel to the pellet to get more energy out for the same input energy. That's not how ICF works. Plasma, being a gas-like state, will always expand to fill whatever volume is presented. With ignition, the rate of expansion is essentially lower than the rate of fusion, allowing you to fuse all of the fuel before the plasma dissipates and cools down. In ICF…

This report found that ICF could reach LCOE as low as $25/MWh "with optimistic but not obviously unrealistic inputs."[0] This does require hohlraums cost about $2 each and are fired every 20 seconds. With mass production and process optimization it may not be ridiculous to reduce hohlaum cost to this amount. However, the yield is about 5 gigajoules which is equivalent to about 1 ton of TNT. Making equipment that can…

"Optimistic but not obviously unrealistic inputs" include reducing the cost of hohlraums from the million dollar range to 10$ (not even sure if that accounts for the price of the gold itself), a reactor capable of resisting 50 million pulses before needing replacement, and a few others.

It also considers the price of a fusion power plant to be less than that of a fission power plant, based entirely on the observation that it would have less stringent safety requirements.

Overall this article may be right in principle if taken to refer to an arbitrarily far away future (hundreds of years away at least, if ITER and DEMO are to be taken as realistic examples of the pace of improvement of fusion power in general, even if they are MCF instead of ICF).

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#282

Post by mchusma »

rfrey wrote: post #61

Meta-question about fusion energy -something I don't understand about the movement. I spent a few years as CTO of a company providing heat-to-electricity plants. We financed and built them off high-heat plants like natural gas turbines. The "fuel" was heat going up the stack - so it was essentially free. We still couldn't compete with conventional electricity plants, even with a $30/tonne price on carbon in Canada. G…

Id answer this in 2 ways:

First.

Let's say we have a trillion people in space stations/multiple planets. Fusion is a energy source that can plausibly power them.

Second.

fission works close to other sources, but is so hampered by regulation that it hasn't gotten to be affordable. This may be fixed in the future. micro-reactors solve the biggest economy of scale issues and a renewed bipartisan interest in nuclear could help it be politically viable. If fission works in theory, fusion definitely works in theory (as the energy output is much higher).

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#283

Post by onion2k »

rfrey wrote: post #61

Meta-question about fusion energy -something I don't understand about the movement. I spent a few years as CTO of a company providing heat-to-electricity plants. We financed and built them off high-heat plants like natural gas turbines. The "fuel" was heat going up the stack - so it was essentially free. We still couldn't compete with conventional electricity plants, even with a $30/tonne price on carbon in Canada. G…

Simple solution - nationalize energy production.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#284

Post by tsimionescu »

jhgb wrote: post #268
tsimionescu wrote: post #81

Earlier quoted context omitted.

> Plasma breakeven is all anyone is really working on. Once you have plasma breakeven you have a self-sustaining heater basically, which then can be used to create energy. The point of an "ignited plasma" is that it's self-sustaining and just pumps out heat, even if most of the energy is used to keep the reaction going. This is dead wrong. First of all, the experiment described here is ICF, in which you have to const…

> the other half is radiated away as hard to capture neutrons, which are almost entirely a waste product I thought the neutrons were supposed to take away the heat, to be absorbed in layers of water?

Reading more about this, it seems that one of the ideas is indeed to capture the neutrons in a liquid lithium blanket, that would then produce both heat and tritium, and using that heat, that is outside the magnetic confinement, to connect to a turbine.

Unfortunately, I believe that the area of actually capturing the energy of the fusion reaction is almost entirely unstudied yet in practice.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#285

Post by iammisc »

junon wrote: post #135
iammisc wrote: post #44

Earlier quoted context omitted.

> I am still bitter that we don't invest more on this research which has the potential to solve the climate crisis "unexpectedly". Unfortunately, solving the climate crisis would put many a pundit out of a job.

Something tells me the alternative is going to do much more than putting people out of jobs.

I agree, but the bureaucrats in charge are more responsive to their own immediate needs than to the long-term outcomes. That is to say, it is in their best interests to prevent an exciting new technology to come out and eradicate the problem as then they would no longer have their jobs.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#286

Post by drran »

zpeti wrote: post #158
cletus wrote: post #146

Earlier quoted context omitted.

> How is fusion different? It's not but people don't seem to realize this or maybe just don't want to think about it. Spending $100B to produce 1GW of power (made up numbers) is not an economical source of power. So hydrogen being free (deuterium and tritium are essentially free; Helium isotopes are more complicated) is irrelevant until the capital cost of the plane is much, much lower. And even then you still have t…

$100bn to get to a working fusion reactor doesn’t mean the second one will cost €100bn as well…

Yep, but if you want to have cheap energy, then it better to start with something cheaper, like LENR, which is still pain to reproduce, but give it $100bn and 20 years and then compare with ITER.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#287

Post by nomel »

xondono wrote: post #226
orangepurple wrote: post #66

Earlier quoted context omitted.

You can't put a price on energy independence in a free market economy. Energy independence is a military objective and a matter of national security. The costs are difficult to put in perspective.

Of course you can. The price of energy independence is the lowest total cost that can keep up with energy demand. The question is if fusion is really the cheapest way to do it, say vs alternatives.

> lowest total cost that can keep up with energy demand

It’s not trivial since it’s difficult to predict if that external supplier will eventually decide to twist you arm to maintain their energy stream.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#288

Post by rfrey »

ChuckMcM wrote: post #228
rfrey wrote: post #61

Meta-question about fusion energy -something I don't understand about the movement. I spent a few years as CTO of a company providing heat-to-electricity plants. We financed and built them off high-heat plants like natural gas turbines. The "fuel" was heat going up the stack - so it was essentially free. We still couldn't compete with conventional electricity plants, even with a $30/tonne price on carbon in Canada. G…

I could cite you things like this: ( https://www.osti.gov/biblio/6276900 ) but they will likely be buzzword soup. The simplest explanation is that the fusion reactor's energy output is the _primary_ heat source for a heat engine like a steam turbine. It sounded from your description that your company was targeting so called "waste" heat, which is a lower grade of heat (smaller delta between ambient so a smaller tempe…

Sure, I understand delta-T, and Carnot haunts my nightmares.

My question about fusion isn't about thermodynamic efficiency, but about economics. Our waste heat solutions produced electricity at about 2x the LCOE of a natural gas turbine. Since it was carbon-free electricity, by selling the carbon credits we could get close to the ROI of a natural gas plant. A NG plant might have a 20 year IRR of 14-16% - we could get to 11 or 12. But that was enough to kill the project.

And we have other technologies that produce carbon free electricity at a price close but not quite at NG turbines - renewables + storage, for example, or geothermal. But those aren't considered economic to build right now, despite being here and ready and understood.

I might be wrong, but I can't imagine a nuclear fusion plant getting within spitting distance of a NG plant for capital cost. And if it's even twice as much money -- which seems wildly optimistic -- maybe nobody will build them. Or maybe they will, because there are other factors at play besides carbon free electricity and cost! That's what I'm asking - what are those other factors?

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#289

Post by rfrey »

ChuckMcM wrote: post #278
AlbertCory wrote: post #263

Earlier quoted context omitted.

Skin in the game [1]. OP has actually done it ("CTO of a company providing heat-to-electricity plants"). Have you? Or you just read about it? [1] https://www.amazon.com/Skin-Game-Hidden-Asymmetries-Daily-eb... ?

I get that, 100% props for the experience. And I totally respect it. The GP question was "what makes fusion different", and the only thing that is different really is the economics of how much it costs vs how much energy you get out. Energy out is, by definition, the amount of heat differential you can generate. Cost is, again by definition, the total operating cost of the heat source. So this is where the author and…

But the LCOE is a normalized (usually to $/kwh) price that accounts for the amount of energy produced for a given capex, plus the operating costs, plus the cost of capital, plus the lifetime of the plant. It tries to bake that all in.

Your position is that LCOE will be much lower, because (as I understand you) the plant cost will scale much better than, say, 100MW natural gas plants. I totally accept that my assertion about LCOE might be wrong because it only costs 2x as much money to build a fusion plant that's 100x bigger.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#290

Post by rfrey »

beambot wrote: post #150
brightball wrote: post #86

Earlier quoted context omitted.

Their carbon emissions are still dramatically lower than those of coal and oil. There are bigger fish to fry than NG. NG is likely going to be a critical transitional fuel for the planet to depend on while we get to more abundant renewable options, grid batteries and nuclear/fusion/thorium.

What time horizon are NG plants capitalized over? Soon enough, that will be a significant factor in the economic equation...

Typically 15 years.
Post reply on HN