Helion Energy to demonstrate net electricity production by 2024

[jrvz]

With He3 selling for $20,000/g and tritium for $30,000/g, I wonder if they can make a profit running on D-D without generating net electricity. At least until the markets for those gasses crash.

[Skipjack]

Yeah, that is something that I have been saying for a while. They will likely burn the He3 and sell the Tritium until the market is saturated. They can go pretty low with the price too (below 1000 USD/gram) before it becomes more profitable to let it decay and burn the resulting He3.

[KitemanSA]

With He3 selling for $20,000/g and tritium for $30,000/g, I wonder if they can make a profit running on D-D without generating net electricity. At least until the markets for those gasses crash.

The problem with saying that tritium is $30,000/g is that it may be because the production cost is very high, or the demand is very low; or both!

[Skipjack]

With He3 selling for $20,000/g and tritium for $30,000/g, I wonder if they can make a profit running on D-D without generating net electricity. At least until the markets for those gasses crash.

The problem with saying that tritium is $30,000/g is that it may be because the production cost is very high, or the demand is very low; or both!

Considering that the whole world is talking about a Tritium shortage, I think that lack of demand is currently not the issue. It is likely production and storage. Helion can go below 1000/g and still make more profit than they would from burning the He3 from its decay.

[sdg]

Just to wrap my head around the cost of D-He3 reactions in initial testing, i tried some reverse-engineered back of the envelope calculations for Orion (or maybe more likely Polaris), assuming 100MJ of harvestable ⁴He (alpha particle) energy, but 50% harvest efficiency factor due to all loses (e.g., non-collisions, electromagnetic recapture, etc.) , and 1 Hz pulse rate:

D + ³He → ⁴He + p, with 80% energy in p (due to mass) and 20% from ⁴He
With e=mc2, that's 3.69 MeV per ⁴He:
³He = 3.016 g/mol divided by 6.022 × 10²³ atoms/mol. = 5.009 × 10⁻²⁴ g. 3.69 MeV per ³He
and 1 MeV = 1.602 × 10⁻¹³ J
So to yield 100MJ ⁴He per pulse requires 1.7 × 10¹⁴ ³He reactions.
With the 50% all-cause energy harvest loss, that's 50MJ, and 1 pulse per sec dials in at 50MW, the design goal for Orion.
That means ³He mass = (3.4. × 10²⁰ atoms) × (5.0 × 10⁻²⁴ g/atom) = 1770 μg of He3 per pulse * 3600 pulses per hour at 1Hz = 6.37 g/hr ³He.
At $20,000 /gram ³He, that's about $127,000 per hour for 50MW machine at 1 Hz.

Which is actually a lot less than I was imagining, as this is the cost assuming current market (no breeding). Or, for example the cost for experimental D + ³He runs on Polaris. Lot's of assumptions here, and maybe I got the math wrong. And post any corrections if so inclined.

But if ballpark, Helion could buy a million dollars of ³He and expect to be able to run almost 8 experimental hours @ 50MW. Which is not cheap but certainly not prohibitive, and I would argue it's a drop in the bucket for proving out net energy, if in fact it can achieve that under these simplistic assumptions. That's a boatload of diagnostic and engineering design validation and/or fault identification/resolution time.

Obviously, this is not cost effective at that high ³He cost, as 8 hours of 50MW produced from a natural gas fired plant is about $12K.

[Skipjack]

I don't quite understand this calculation. It seems like you are ignoring the p completely?
Also, Helion should have a lot lower losses than 50%.

[jrvz]

Suppose that, on each pulse, a fraction s of the He3 does not fuse. So a fraction s^2 survives two pulses, a fraction s^3 survives three pulses, etc., and a given He3 survives n=s/(1-s) pulses on average. Now let c = the energy per pulse per He3 to heat and compress the plasma, y = energy yield when the He3 eventually fuses, and h be the fraction of plasma energy (from the He4, p, and unreacted fuel) not recovered. Then the net energy per He3 that's lost is (y - nc)h. I think sdg is estimating (y-nc)h/y, rather than h.

Helion has demonstrated they can recover over 90 percent of the energy required to compress and heat their plasma. I don't think we know what fraction of the He3 will fuse on each pulse, nor how efficiently they can recover the energy from the p and He4.

[Skipjack]

The input energy recovery will always be the same, no matter how much of the fuel fuses.

[jrvz]

John Slough has written an article "A compact fusion reactor based on the staged compression of an FRC". He describes an approach to forming and heating an FRC that "is expected to achieve fusion gain as large as 10" with D-T fusion. He describes a number of constraints on device parameters to ensure FRC formation and stability.

However, D-3He fusion will require a seven times higher ion temperature, for which he calculates the fusion energy gain will be reduced by a factor of 240. The reduction in gain for the P-11B fuel cycle pursued by TAE would be even worse.

There's a preprint at https://iopscience.iop.org/article/10.1 ... ae034d/pdf.