[brofallon]

I'm still a little unclear on the benefits that fusion offers compared to things like wind and solar. I understand that we need to develop better storage technologies for the energy produced by wind and solar, but that seems so much easier than the challenges currently facing fusion. Wind and solar just seem so far ahead of fusion already - they're pretty cheap and very widely deployed on a global scale. In comparison fusion seems very expensive and unproven and even when we get everything to work it might not be much better than a solar farm with a big battery pack. But maybe I'm missing something important about the economics?

[thehappypm]

It’s potentially just a much better version of fission.

Fusion won’t cause a runaway reaction — in fact it’s brutally difficult to get it to react at all, hence why this is an achievement.

It also doesn’t use materials that can be used for a bomb, again unlike fission.

As a result it has the potential to be cheaper to implement, cheaper to fuel, with no meltdown risk.

[valine]

Also don’t forget the biggest benefit over solar/wind: it keeps on generating power on cold windless nights.

[jszymborski]

No need to worry about Cold Dunkelflaut!

https://www.youtube.com/watch?v=Q8xsg9iK5yo

[dharmab]

Isn't tritium used in fusion and a potential weapons material?

[devmor]

It's a fission yield booster. It's as much of a weapons material as charcoal is.

[mlyle]

It's not controlled. It does help boost some fission weapons. But it's not the hard part or critical piece of producing a nuclear weapon, and you can get by without it.

To illustrate how little it's controlled-- I have a little bit on my keychain as an alpha source with a phosphor so my keyring always glows.

[dogma1138]

Depending on the scale and reactor design, we have really good examples of run away fusion reactions. Run away reactions are easy, controlled ones are hard.

And whilst I won’t doubt that if fusion ever becomes commercially viable the reactors would be walk away safe it doesn’t mean that you don’t need to account for that in your design.

[willis936]

What is an example of a run away fusion reaction?

[dogma1138]

The US strategic arsenal.

[blamestross]

A Hydrogen Bomb. It is basically using a nuke (fission) to trigger fusion instead of lasers.

[willis936]

That is a run away fission reaction that ignites a short lived fusion reaction. We don't even talk about neutron populations or k factors in fusion because there is no avalanche effect possible.

[bitcurious]

Wind and solar have a max theoretical output that is constrained by physical space and competition for its use, in addition to weather patterns, etc.

Fusion energy has a theoretical max that’s orders of magnitude higher.

Wind+solar is the path to decarbonization and sustaining our current world.

Fusion is the path to post scarcity. If/when we get scalable commercial fusion, it’ll be like the transition to oil - society will radically change, in ways we can’t predict.

[vlovich123]

> Fusion is the path to post scarcity. If/when we get scalable commercial fusion, it’ll be like the transition to oil - society will radically change, in ways we can’t predict.

Except this is also true for fission. So if fission has failed to transform society, why do you think fusion will?

[pertymcpert]

Uh because building fission reactors, despite being fairly safe, is still a risk compared to fusion? We don’t want to put fission reactors in every town, but we could one day with commercial fusion. And the sheer amount of energy we could harness would allow us to do insane things.

[vlovich123]

> despite being fairly safe, is still a risk compared to fusion

I recommend you read up on the Gen IV reactor designs. They’re totally safe - meltdowns are impossible because of the way the reactor is built. If anything catastrophic happens, the reaction stops and can never get to a runaway reaction (physically impossible). Look up Gen 4 reactors. Those will be available before fusion even gets off the ground (and I’ll note that fusion has 0 reactors built so who knows what kind of safety issues actually come up when engineering theory hits the road).

Even Gen III reactors are fine to put up everywhere (20x margin over Gen II) and Gen III+ reactors continue with the theme of adding passive safety measures that would prevent accidents like Fukushima and Chernobyl. Critics who rate any possibility of accident as unacceptable will never be pleased but that’s not a reasonable position to take because nuclear energy isn’t built in a vacuum and global warming and existing coal power poses a significantly higher threat and renewables and batteries simply can’t scale no matter how hard we believe.

Fukushima and Chernobyl were Gen II designs which do have a cost advantage and EVEN WITH THOSE ACCIDENTS those designs are safer than existing coal and LNG power plants we are fine with having all over the place (nuclear is slightly safer than wind). Even Gen II designs built today are a fair bit safer than Chernobyl and Fukushima. Fukushima also ignored many and repeated safety warnings from internal and external reports although critics will generally point to this as a general criticism against all reactors (even though Fukushima still failed comparatively harmlessly all things considered).

Even with all of that, the death rate per kWH generated is drastically safer than coal and on par with wind and solar. Also construction costs tend to go down when the regulatory environment doesn’t inhibit building reactors due to political fears that aren’t grounded in the actual engineering.

I’ll also note that China is building many many nuclear reactors and Russia is also following suit. So from a competition/national security perspective, China and Russia both have access to significantly more clean energy and more energy independence than we do.

Look. I understand there are problems with fission reactors. They remain the only feasible way to generate nuclear power in the next 60-100 years at scale. Yes there are downsides and risks. However there’s one big upside vs fusion: it exists. It’s possible to build these plants now without physics and engineering breakthroughs we haven’t made yet. The advantages of fusion are safety, nuclear waste management, theoretical proliferation concerns. There’s no reason to believe construction costs will be significantly lower. Even if they are, we’re not even close to the first real commercial power plant even with this achievement as impressive as it is from a progress perspective.

[pertymcpert]

I answered why fusion would change the work in ways different to how fission changed the world.

> Look. I understand there are problems with fission reactors. They remain the only feasible way to generate nuclear power in the next 60-100 years at scale. Yes there are downsides and risks. However there’s one big upside vs fusion: it exists.

If you re-read the original comment, it supposed that fusion exists. You can't criticize something in development for not existing and use that as a point against why it won't be beneficial. That's circular reasoning.

> The advantages of fusion are safety, nuclear waste management, theoretical proliferation concerns.

Yeah, just nuclear waste management. No big deal.

> They remain the only feasible way to generate nuclear power in the next 60-100 years at scale.

You absolutely cannot predict with that level of certainty over 100 year time scales. You severely underestimate how much we can achieve over timescales as long as that.

[dark-star]

Wind and solar only provide power during wind / during the day. Fusion can provide 24/7 power. Battery packs can only store so much energy, and Lithium is a contested resource as most of the Lithium produced is required by the automotive industry these days, and the largest deposits are in regions where you maybe don't want to get your Lithium from (child labor, unsafe conditions, politically unstable countries, etc.)

But yeah, future energy will be a mix of available technologies, not a single technology alone. So you need e.g. fusion (or fission) for "baseline" power and wind/solar for peaks

[anon291]

Solar and wind have massive environmental impacts. Fusion's foot print is much smaller for the same output. Batteries are rather dangerous. Fusion is -- as far as I understand it -- much less likely to escape a reactor due to how difficult it is to sustain the reaction. Moreover, it's more dependable.

So in sum, the advantages are (1) dependability, (2) safety, and (3) small footprint.

[josho]

> Solar and wind have massive environmental impacts

Got a source for this? The only time I've seen this has been political talking points that had no backing.

[anon291]

My source is the fact that solar panels cause shade on the ground and squander energy that would normally be going towards developing biomass into developing energy instead. It just doesn't seem healthy for the animals and environment that live there. Especially with the talk of in ground installation, which basically destroys entire environments and soils and covers it with impermeable membranes. That's not great for soil health.

[grecy]

I’ve driven many many tens of thousands of miles through landscapes with intense sun and extremely close to zero vegetation or life.

Damaging that has got to be a lot better for the planet than coal or nuclear.

[anon291]

Even the great deserts of the southwest have life. In fact, I challenge you to drive through these tens of thousands of miles of landscapes in the hour or two after a rainstorm and tell me they're dead. You're missing out if you've not seen the desert in bloom.

I grew up by the desert, and I don't know why people think it's dead. There are some extremely fragile ecosystems there.

[grecy]

> great deserts of the southwest

Sounds like you're talking about a single country?

I'm talking about when I've driven through the Sahara (West and East side), Namib, Simpson, Great Sandy, Gibson, etc. etc.

There is a HUGE amount of land on earth for things like solar and wind.

[karaterobot]

Apart from the safety improvements and environmental benefits, it's a way to produce a ton of energy. I believe it's about 4 times as much energy from fusion compared to fission with the same amount of fuel. I'm a fan of solar and wind, but it's going to be way easier to power the entire world sustainably if you've got fusion in the mix.

[ridgeguy]

I think when comparing PV/wind to nuclear (fusion or fission) generation, we should include the cost of storage for renewables in the comparison.

Renewable generation + storage gives a system that's capable of meeting base load needs, just as nuclear generation does. Cost comparisons among base load-capable technologies is a better way to evaluate the economics, IMHO.

[jasonhansel]

If we get an order of magnitude more energy, we can do an order of magnitude more things; fossil fuels gave us the Industrial Revolution, and nuclear fusion may unlock something similar.

[zardo]

> But maybe I'm missing something important about the economics?

I think you've understood it.

Imo fusion is never going to be able to compete with renewables+storage with the energy being captured from neutrons. Maybe reactions that release energy in charged particles or photons could, but they're even harder to do.

[Analog24]

Could you elaborate on your point a bit more? If you're talking about utilizing the weak force vs. the residual strong force then I'm not sure this argument holds up.

Also, when comparing to renewable+storage you have to consider how much land has to be dedicated to energy use in these scenarios. Wind and solar require orders of magnitude more than a potential fusion reactor (or an existing fission reactor).

[zardo]

Just referring to what particles the released energy is carried in.

The easiest fusion reactions to make happen release most energy as neutrons. But neutrons are, from a practical standpoint, a huge pain in the ass to deal with. They just fly off until they hit another atomic nucleus.

They irradiate the structure of reactor, making it radioactive and weakening it, neccesating periodic replacement. This means handling radioactive materials, which as the existing nuclear power industry demonstrates, is hard to make cheap.

Reactions that release excess energy as charged particles, though all harder to actually do, leave you with charged particles that can be directed by electric or magnetic fields and can be used for direct enerergy conversion.

Yes solar requires a lot of surface area, but fusion power is just not looking like it will be anywhere near cheap enough for the real estate savings to matter.

[Analog24]

Neutrons aren't that hard to capture. They are certainly harder to capture than charged particles but there are plenty of materials that are dense enough to reliably capture neutrons. This is how heat is extracted from the reaction to use in a generator. The activation of the containment material is a problem but it's not even close to the level it is for fission reactors where you're forced to deal with spent fuel rods.

At the moment fusion is obviously not cheap but no one is planning on using the technology in its current form for actual power generation. The processes involved will all get more efficient and given the astronomical upper limits of energy output from fusion it doesn't take a big stretch of the imagination to think that it will eventually be preferable to solar and wind power. There's no guarantee that will happen but hopefully this breakthrough will trigger more investment and momentum to make it a reality. I also want to add that I'm very pro solar and wind, especially in the short term.

[ragebol]

Fusion brings the power of the stars directly to us, without it capturing the energy millions of miles later. It unlocks a Star Trek, post-scarcity future that PV and wind cannot bring due to their space requirements.

Also, you could eventually put one on a spaceship or other planet. For that Star Trek future.

[UltraViolence]

Much more compact, less use of land or sea real estate, more power produced per volume and throttleable.

[galuano1]

Predictable and abundant supply of fuel, and hopefully greener to produce the powerplant itself.

[abecedarius]

High power density. Start and stop on demand. Abundant fuel is another advantage, but in our neighborhood sunlight is also abundant. Fission also has good power density, but not so good on the start/stop flexibility.

[xzlzx]

Consistent baseline grid load is the difference.

[vfclists]

Industry does not run on solar and wind and sad to say it, current storage energy is not green.

The cleanest energy available now is nuclear fission, but there is no money in it for the energy industry. It is too plentiful and cheap if implemented properly and capitalism does not like plentiful and cheap.

France has had cheap electricity for decades and it seems it has been so cheap that they don't want it anymore.

This is all capitalist boondoggles.