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Englishgrinn t1_j03ka2i wrote

Reply to comment by Robo-Connery in National Ignition Facility (NIF) announces net positive energy fusion experiment by Robo-Connery

As a layman who is not scientifically literate, I appreciate this simplified breakdown I could follow.

I hope I'm not just being foolish when I ask this, but: If the gains in efficiency, output and collection tech you mention are all technically possible, does that make the ultimate goal unlimited (or an arbitrarily high amount of) clean energy? A solution to our energy/climate crisis for good? Or is that just science fiction and excitement blurring my understanding? Is the real goal just another clean energy alternative? Something that could practically lower emissions as one part of a larger strategy?

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Robo-Connery OP t1_j03lmw0 wrote

So efficiencies gains are always possible but probably not unlimited. There are also fundamental science problems for both fusion regimes that need to be solved (even though I will claim ICF has far more of those problems).

> A solution to our energy/climate crisis for good?

I have a bog standard answer to this question: Just because there is unlimited fuel doesn't make it cheap. Fusion reactors will be, for the foreseeable future, extremely expensive. This means the energy they produce will be very expensive.

However, they will get cheaper as we learn to make them better and as energy prices rise there will always be a tipping point where they make economic sense. More importantly though is your mention of climate. While there are obviously some co2 emissions associated with fusion (due to the plant needing built and operated and the fuel collected etc.) the amount is trivial so the environmental benefit of fusion is huge. Traditional Nuclear power also shares many of these benefits too but produces larger quantities of waste (though fusion still causes nuclear waste due to neutron activation of materials) and requires larger quantities of fuel.

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m-in t1_j06ohmr wrote

It’s also worth mentioning what does it mean to be “expensive”: it’s not about numbers in a database in a bank somewhere. It’s about how much energy it takes to make all the stuff that you need for a fusion power plant.

Let’s now imagine that we’ll get to a stage when the first commercial fusion plant can be built

The design, build, and commissioning process of that plant will take about as much energy as that plant will produce through its entire lifetime. It’ll be basically sunk cost for investors just to get the design and operating process shaken down and ready for the next build. And that’s optimistic.

High tech plants like that take hundreds of thousands of man-hours of work, if not millions. While that work is going on, you’re spending resources just to feed and keep the workforce happy - a gross oversimplification, but think of how many resources it takes to run the equivalent of a large residential subdivision. That’s just to keep those people alive and happy so they can do their 8 hours of work per workday. And those people live across the planet pretty much, since many different industries will be providing raw materials, machining, design, assembly, and a host of other services.

As the technology advances and more plants are built, it’ll become profitable to operate one. Not the first one. Not the second one either.

*Happy workforce is a relative term and I’m far from claiming working people everywhere are happy with their jobs. What we should strive for, though, is for big projects to contribute to workers’ well-being everywhere in some way.

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yves759 t1_j04mipr wrote

Whether an energy is "clean" or not, whatever that means, the use of it is by definition not clean, energy is our power to act on/transform the environment : the vast amount of energy that fossile fuel today provides, is what allows to build roads, houses, fish the whole oceans, cut forests like crazy, etc

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rmzalbar t1_j05ou6e wrote

But with enough "free" energy you can reduce or do away with many of those things. Farming could be replaced with high-density hydroponics instead of slash-and-burn, oil burning transportation could be replaced with electric, etc. Getting humans as a global community to stop doing.. well, everything.. and sit on their hands in the darkness and starve, is not realistic because they simply won't do that. But if you can offer them something that is cleaner and better they'll take it.

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yves759 t1_j060v0m wrote

Well, regarding "and sit on their hands in the darkness and starve, is not realistic because they simply won't do that." , it might not be a matter of "choice" at all ...

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rmzalbar t1_j062hea wrote

Oh, of course. Nevertheless, they'll continue to destroy stuff in order to put the next meal on the table or iphone in their hands, regardless of how badly you might want them to think long term.

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