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A comment on Wendelstein 7-X: Gigajoule energy turnover generated for eight minutes. Parent comment

Re:Wendelstein 7-X: Gigajoule energy turnover generated for ... by DennisP on Friday August 11, 2023 @07:36PM (#37095327)
Helion's fuel mix produces just 6% of its energy as neutron radiation, and if you harvest it you'll lose a third of that. As long as you have enough net energy, collecting that 4% might not make financial sense.

With fuel costs insignificant, your cost per kWh is mainly capital cost. Let's say it's all capital just to keep it simple. I don't know how much the input energy will be but if your choice is between, say, generating net energy of 50MW without a turbine or 54MW with a turbine, then you would skip the turbine if it adds more than 8% to the capital cost. I suspect Helion has done this calculation in detail.

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Re:Wendelstein 7-X: Gigajoule energy turnover generated for ... by MichaelZuo on Saturday August 12, 2023 @11:51AM (#37101411)
It does seem to hinge on the cost of fuel, I have some doubts about whether they can secure a fuel supply so cheap as to skip out on that extra 4 MW, even after factoring in the cost of a small steam turbine installation.
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Re:Wendelstein 7-X: Gigajoule energy turnover generated for ... by DennisP on Saturday August 12, 2023 @01:58PM (#37102629)
Deuterium costs several thousand dollars/kilogram. But even though it is just one part in several thousand of the hydrogen in water, there's enough deuterium in your morning shower to provide all your energy needs for a year.[1] Cost of deuterium is definitely insignificant.

Helion's other fuel is helium-3 which they'll make themselves by fusing deuterium. So the helium-3 cost will directly depend on the capital cost of the reactor producing it.

[1] https://dothemath.ucsd.edu/2012/01/nuclear-fusion/

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