7 ms·

I tried to do some back-of-the-envelope calculations on what this means in regards to energy costs being saved, because I couldn't find a direct source (maybe G

I tried to do some back-of-the-envelope calculations on what this means in regards to energy costs being saved, because I couldn't find a direct source (maybe GPT could help actually). Anyway, based on ITER [1] to equate the energy production of a 1000MW coal plant you would need 2.7t of coal for that plant or 250kg of deuterium and tritium for the fusion reactor (split equally). Based on [2] deuetrium costs about ~$15k a kg. But tritium is ridiculously expensive, at $30k per gram (!) [3]. This leads to a calculation of ~$700M for the coal plant and ~$3.75B for the fusion plant (of which only ~$1.5M is deuterium) I have a few questions and I wonder if any can help: 1. Is the above fusion fuel correct? 2. What measures are expected to bring these prices down to price efficiency? Of course, I am not calculating the cost it would take for the reactor, storage, delivery etc. Nevertheless, this is an absolutely incredible development and the people working for this progress should be definitely proud of their work. My generation and the ones following will hail this as a breakthrough moment. Thanks! [1]: https://www.iter.org/sci/FusionFuels https://www.iter.org/sci/FusionFuels [2]: https://en.wikipedia.org/wiki/Prices_of_chemical_elements https://en.wikipedia.org/wiki/Prices_of_chemical_elements [3]: https://www.science.org/content/article/fusion-power-may-run-fuel-even-gets-started https://www.science.org/content/article/fusion-power-may-run...

JumpCrisscross 4y ago
> tritium is ridiculously expensive, at $30k per gram D-T fusion almost always breeds tritium in the blanket.
- panosfilianos 4y ago
  Would that mean that you wouldn't need titium to start with? Or that tritium deposits would replenish? How would it affect the rough calculations above?
  - JumpCrisscross 4y ago
    > Would that mean that you wouldn't need titium to start with? Tritium decays in a decade. To start, you'd need the expensive stuff harvested from the heavy water of spent fuel pools. After that, you'd let your neutrons breed it in lithium (or boron, if you're fancy).
    - panosfilianos 4y ago
      So, the approach here would be that it would just be a much more efficient process.
  - wernercd 4y ago
    I would also wonder if Titium is that expensive... and it generates titium... would that be part of the "break even" equation? Creating something rare to sell?
    - Kubuxu 4y ago
      It is so rare because tritium is not found in nature in any significant quantity. The amount on the market comes from water recovered from water pools used for spent nuclear material storage. There also is no enormous market for tritium. So in short, fusion reactors exist on both sides of the tritium market, by becoming the primary producers and consumers of it, which should lead to significant drop in price of tritium.
    - ceejayoz 4y ago
      Current demand is a couple hundred grams per year. We just don't need that much of it. The cost per gram would go down a lot if we needed to mass-produce it.
      - panosfilianos 4y ago
        I think what I'm alluding to is, how much can the cost go down. In the case of fossil fuels there value is strongly based on their physical scarcity and cost of extraction/delivery etc. How much do these things ring true in this case and what are ideas of improvement?
  - creato 4y ago
    Your calculations don’t mention energy (J), only power (MW in your post). Fuel supply and cost correlate with energy produced, not power. Parent post suggests that tritium is a fixed cost, more like a construction cost than a fuel cost. We can’t answer this question without a lot more information. We’d need to know how much tritium is needed to reach the point the reactor breeds more than it consumes, if at all.
trillic 4y ago
I'd imagine commodity tritium breeders would be a part of the infrastructure build out and that it will be a highly competitive space as fusion-to-the-home nears reality.
- onlyrealcuzzo 4y ago
  What is fusion-to-the-home?
  - aliqot 4y ago
    Power derived from a fusion power plant delivered through conventional powerlines leading to the consumer.
  - LegitShady 4y ago
    probably one of those mr fusion units from back to the future.
gene-h 4y ago
[0] provides economic analysis for this type of power plant. They conclude it would not be unreasonable to get levelized cost of energy could get as low as $25/MWh. For this one really needs a high gain of 1000, although gains of 400 are a bit more reasonable, and a gain of around 100 may be economically competitive in some cases. While the gain NIF achieved was about 1.5, there is good reason to expect it can be scaled up. Ignition is a runaway process, so small changes in the input can result in large changes in the output. Hydrogen bombs, which also use a burning plasma as was demonstrated here, also suggest that the gain and yield may be scaled up. [0]https://royalsocietypublishing.org/doi/10.1098/rsta.2020.0053 https://royalsocietypublishing.org/doi/10.1098/rsta.2020.005...
- panosfilianos 4y ago
  Thanks a ton for that! $25/MWh is great but not the 10x economic impact I expected. Especially since [1] we see PV at $50/MWh currently. [1]: https://en.wikipedia.org/wiki/Cost_of_electricity_by_source https://en.wikipedia.org/wiki/Cost_of_electricity_by_source
  - devmor 4y ago
    The economic impact doesn't just come from the fuel to energy ratio. One of the biggest differences is also in the space required. Nuclear fusion reactors could eventually end up being very small - like smaller than an SUV. Imagine the cost savings in miniaturizing electrical grids.
    - panosfilianos 4y ago
      This seems interesting but not especially impactful. For me, the question here is: can we get our energy to cost 90% less than it did? Don't get me wrong, I recognise that this is still a huge win (especially environmentally) and that it can have huge runway effects (eg. much more effective decentralization etc.) but it's quite interesting on how we can get these billions of people out of poverty first (or during).
      - 4y ago
pohl 4y ago
jboy55 4y ago
This isn't for power plants, this is to model the efficiency of the second stage of a stored h-bomb in place of periodically exploding them, which we can't do anymore due to the test-ban treaty.

JumpCrisscross 4y ago

> tritium is ridiculously expensive, at $30k per gram D-T fusion almost always breeds tritium in the blanket.

panosfilianos 4y ago
Would that mean that you wouldn't need titium to start with? Or that tritium deposits would replenish? How would it affect the rough calculations above?
- JumpCrisscross 4y ago
  > Would that mean that you wouldn't need titium to start with? Tritium decays in a decade. To start, you'd need the expensive stuff harvested from the heavy water of spent fuel pools. After that, you'd let your neutrons breed it in lithium (or boron, if you're fancy).
  - panosfilianos 4y ago
    So, the approach here would be that it would just be a much more efficient process.
- wernercd 4y ago
  I would also wonder if Titium is that expensive... and it generates titium... would that be part of the "break even" equation? Creating something rare to sell?
  - Kubuxu 4y ago
    It is so rare because tritium is not found in nature in any significant quantity. The amount on the market comes from water recovered from water pools used for spent nuclear material storage. There also is no enormous market for tritium. So in short, fusion reactors exist on both sides of the tritium market, by becoming the primary producers and consumers of it, which should lead to significant drop in price of tritium.
  - ceejayoz 4y ago
    Current demand is a couple hundred grams per year. We just don't need that much of it. The cost per gram would go down a lot if we needed to mass-produce it.
    - panosfilianos 4y ago
      I think what I'm alluding to is, how much can the cost go down. In the case of fossil fuels there value is strongly based on their physical scarcity and cost of extraction/delivery etc. How much do these things ring true in this case and what are ideas of improvement?
- creato 4y ago
  Your calculations don’t mention energy (J), only power (MW in your post). Fuel supply and cost correlate with energy produced, not power. Parent post suggests that tritium is a fixed cost, more like a construction cost than a fuel cost. We can’t answer this question without a lot more information. We’d need to know how much tritium is needed to reach the point the reactor breeds more than it consumes, if at all.

trillic 4y ago

I'd imagine commodity tritium breeders would be a part of the infrastructure build out and that it will be a highly competitive space as fusion-to-the-home nears reality.

onlyrealcuzzo 4y ago
What is fusion-to-the-home?
- aliqot 4y ago
  Power derived from a fusion power plant delivered through conventional powerlines leading to the consumer.
- LegitShady 4y ago
  probably one of those mr fusion units from back to the future.

gene-h 4y ago

[0] provides economic analysis for this type of power plant. They conclude it would not be unreasonable to get levelized cost of energy could get as low as $25/MWh. For this one really needs a high gain of 1000, although gains of 400 are a bit more reasonable, and a gain of around 100 may be economically competitive in some cases. While the gain NIF achieved was about 1.5, there is good reason to expect it can be scaled up. Ignition is a runaway process, so small changes in the input can result in large changes in the output. Hydrogen bombs, which also use a burning plasma as was demonstrated here, also suggest that the gain and yield may be scaled up. [0]https://royalsocietypublishing.org/doi/10.1098/rsta.2020.0053 https://royalsocietypublishing.org/doi/10.1098/rsta.2020.005...

panosfilianos 4y ago
Thanks a ton for that! $25/MWh is great but not the 10x economic impact I expected. Especially since [1] we see PV at $50/MWh currently. [1]: https://en.wikipedia.org/wiki/Cost_of_electricity_by_source https://en.wikipedia.org/wiki/Cost_of_electricity_by_source
- devmor 4y ago
  The economic impact doesn't just come from the fuel to energy ratio. One of the biggest differences is also in the space required. Nuclear fusion reactors could eventually end up being very small - like smaller than an SUV. Imagine the cost savings in miniaturizing electrical grids.
  - panosfilianos 4y ago
    This seems interesting but not especially impactful. For me, the question here is: can we get our energy to cost 90% less than it did? Don't get me wrong, I recognise that this is still a huge win (especially environmentally) and that it can have huge runway effects (eg. much more effective decentralization etc.) but it's quite interesting on how we can get these billions of people out of poverty first (or during).
    - 4y ago

pohl 4y ago

jboy55 4y ago

This isn't for power plants, this is to model the efficiency of the second stage of a stored h-bomb in place of periodically exploding them, which we can't do anymore due to the test-ban treaty.