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by Brometheus 1278 days ago
Yes, the fusion needs "huge" amounts of electrical energy input to happen, be it in the form of lasers like here or in the form of magnetic fields like in iter.

In this experiment 2.1 units of input energy produced 2.5 units of output energy. That energy has to be converted to electricity. Conversion looses like 40% of energy (escapes unsused) – so you have produced 1.5 units of electricity from 2.1 units of electricity input.
3 comments
marssaxman 1278 days ago
Sure, that's always been the challenge with fusion. I mistook you to be implying that there was something uniquely difficult about generating electricity from heat produced by fusion, but now I suppose you were simply describing the overhead involved.
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zardo 1278 days ago
It's energy_out/energy_in, but the energy_in is not the total energy used by the experiment, it's the fraction that is transferred to the fusion fuel.
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greggarious 1278 days ago
>In this experiment 2.1 units of input energy produced 2.5 units of output energy. That energy has to be converted to electricity. Conversion looses like 40% of energy (escapes unsused) – so you have produced 1.5 units of electricity from 2.1 units of electricity input.

Thanks for distilling this into one three simple sentences, I know from my brief career in science policy how hard that can be. (You should write 1 pagers for the US Congress :-))

To get back on topic:

So basically, if I'm understanding you correctly: this is an increase in efficiency but not one such that it makes sense economically to generate power in this way?

Is this a large jump in efficiency from previous attempts?

The reason I ask is that I know physics can be incremental, so I don't want to detract from the contributions of the authors... and by all means, it's the type of thing I'd expect to see on HN if so and I'm glad it was shared.

I was just surprised to see many more mainstream sites, geared towards a more general audience, running stories about what I'd expect to be more of a niche discovery.

(Possibly as more of a geopolitics thing -- much like if someone is arrested no one recalls with equal vigor when the charges are dropped, a PR-y article about a minor but important discovery can influence public opinion and be a tool of geopolitics.)

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