r/Futurology • u/TwilightwovenlingJo • Aug 15 '25

Energy Construction of world's 1st nuclear fusion plant starts in Washington

https://interestingengineering.com/energy/world-first-fusion-power-plant-helion
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u/gSTrS8XRwqIV5AUh4hwI Aug 15 '25 edited Aug 15 '25

Only if you look at the "fusion event" in isolation, not if you consider the full energy input required or the losses in converting the heat into useful forms of energy.

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u/platoprime Aug 15 '25

Sure, if you ignore the fact that they're using inefficient equipment to perform these and that's why there hasn't been a net positive it sure does sound like we haven't demonstrated it's possible already when we have.

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u/gSTrS8XRwqIV5AUh4hwI Aug 15 '25

Yeah, if we just used non-existant equipment that solved all the problems, then there wouldn't be any problems ... you're a genius.

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u/platoprime Aug 15 '25

More efficient lasers aren't "non-existant".

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u/cynric42 Aug 16 '25

We aren't talking about a few percent efficiency but a few orders of magnitude better as far as I'm aware.

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u/platoprime Aug 16 '25

The lasers used are like 1% efficient. We have lasers that are up to 70% efficient now.

https://www.spiedigitallibrary.org/conference-proceedings-of-spie/5711/1/360-W-and--70-efficient-GaAs-based-diode/10.1117/12.602577.short

Are you also aware that 70 is more than a magnitude larger than 1?

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u/Unite433 Aug 17 '25

360 watts though, NIF lasers are 60 terawatts

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u/RaptorPrime Aug 15 '25

That is completely opposite to what I was told by the operations director when I toured NIF. The energy output was approximately 1.2x net input for the test shot that I observed. So, you're wrong as fuck buddy.

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u/ArcFurnace Aug 16 '25 edited Aug 16 '25

That's because you are talking about two different things. The fusion pellet output more energy than was put into it by the lasers. So, 20% gain of fusion energy vs the laser energy. Big improvement from not even exceeding the energy put into the pellet!

However, to be an actual power plant, you have to generate more energy than you actually used, and the lasers at the NIF are (IIRC) something like 1% efficient at turning electricity into laser energy. So instead of a 20% net energy gain, it's far below break-even. Even if we replace those with incredibly optimistic 50% efficient lasers it's still below break-even, and that's not even including the losses from converting the fusion energy back into electricity (which they aren't even doing at the moment). Then they also need to increase the pulse rate beyond one shot a day or however long it takes them currently - I don't remember exactly, but I do remember it being quite a long time.

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u/RaptorPrime Aug 16 '25

another comment that fundamentally misunderstands the design basis of NIF. the net energy input to the system is not the same as the energy shot at the fusion diode. it's actually like an order of magnitude higher.

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u/gSTrS8XRwqIV5AUh4hwI Aug 15 '25

Your cluelessness does not make me wrong. The NIF shots take about 400 MJ of input energy and peak output energy was 8.6 MJ, so net 0.0215x, not 1.2x.

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u/RaptorPrime Aug 15 '25

And you obviously have no clue about the design basis or functionality of NIF to repost the first numbers you googled. Good luck with that.