5 ms·

In a separate line of inquiry, this is what I’ve been thinking about wrt fusion lately. Even if the “fusion” part were free, how much would the electricity cost

In a separate line of inquiry, this is what I’ve been thinking about wrt fusion lately. Even if the “fusion” part were free, how much would the electricity cost just based on the steam generator turbine part? (More generally, the sum of all the non-fusion parts of a fusion power plant) Further, if electricity from a fusion plant were effectively free (like it didnt need turbines or something) what would large-scale desalination cost even if it did use truly free energy? This is what I’d be excited for from fusion power, because potable water scarcity is a huge upcoming/ongoing problem in some developing nations with very large populations.

Retric 2y ago
Nuclear fission and fusion power plants can use sea water for most of their needs no need for desalination when you just want thermal mass. Remember nuclear subs operate under the ocean. Deuterium requires processing a great deal of water, but can be moved around the world cheaply at the levels needed for fuel. As to the costs of fusion or fission power if the nuclear bits were free, it’s roughly half the cost of coal.
- reaperman 2y ago
  I meant the economic effects of using fusion as a cheap energy source to provide drinking water to ~1 billion people or so (some part of the population who live in places which currently cannot afford to provide their citizens with proper potable water). Desalination uses a ton of electricity. It's a very significant portion of the cost (~50%). But even if the energy from fusion was magically absolutely free, it would "only" reduce the cost of desalination by about 50%. This might not be enough for those who need it. It's a parallel to how with a fusion power plant, even if the reactor only cost $50,000 (some comically small amount near zero), the electricity from the overall power plant connected to the reactor might still be fairly expensive. Like - if you have access to free steam, is turbine generation actually cheaper than solar? Even assuming absolute best-case, fusion's place might not be "lowest cost source of energy" but rather "a notably cleaner and lower-cost base load" which can provide electricity when weather causes the solar and wind farms to underproduce. In 30 years in developed nations, its competition will be batteries, pumped hydro, and other energy storage farms.
  - Retric 2y ago
    Ops accidentally removed: Compared to PV free energy might reduce the cost of desalination by 1/3, but fusion isn’t going to be free. The core issues is drinking water is isn’t generally a lack of water. People in rainforests still have issues getting clean water because maintaining a distribution system requires a functioning society/government which simply isn’t available in extremely poor countries. Similarly keeping water supplies drinkable requires pollution controls which is basically non existent in such countries.
    - reaperman 2y ago
      Yep - so it's kind of a check for "Am I overexcited about fusion energy?". Seems like it would be nice to have the fusion option if it works out but we can maybe get the same benefits promised by fusion from wind + solar + a few days of energy storage. Either way it doesn't seem like it will be truly revolutionary at this point - as you showed, our problems are bigger than just cheap/clean energy, and we do have seemingly viable options for that on the near horizon anyways without fusion. I'm pro-fusion, I'd like to see more resources allocated towards its development, but my outlook on its potential impact is very tempered.

Retric 2y ago

Nuclear fission and fusion power plants can use sea water for most of their needs no need for desalination when you just want thermal mass. Remember nuclear subs operate under the ocean. Deuterium requires processing a great deal of water, but can be moved around the world cheaply at the levels needed for fuel. As to the costs of fusion or fission power if the nuclear bits were free, it’s roughly half the cost of coal.

reaperman 2y ago
I meant the economic effects of using fusion as a cheap energy source to provide drinking water to ~1 billion people or so (some part of the population who live in places which currently cannot afford to provide their citizens with proper potable water). Desalination uses a ton of electricity. It's a very significant portion of the cost (~50%). But even if the energy from fusion was magically absolutely free, it would "only" reduce the cost of desalination by about 50%. This might not be enough for those who need it. It's a parallel to how with a fusion power plant, even if the reactor only cost $50,000 (some comically small amount near zero), the electricity from the overall power plant connected to the reactor might still be fairly expensive. Like - if you have access to free steam, is turbine generation actually cheaper than solar? Even assuming absolute best-case, fusion's place might not be "lowest cost source of energy" but rather "a notably cleaner and lower-cost base load" which can provide electricity when weather causes the solar and wind farms to underproduce. In 30 years in developed nations, its competition will be batteries, pumped hydro, and other energy storage farms.
- Retric 2y ago
  Ops accidentally removed: Compared to PV free energy might reduce the cost of desalination by 1/3, but fusion isn’t going to be free. The core issues is drinking water is isn’t generally a lack of water. People in rainforests still have issues getting clean water because maintaining a distribution system requires a functioning society/government which simply isn’t available in extremely poor countries. Similarly keeping water supplies drinkable requires pollution controls which is basically non existent in such countries.
  - reaperman 2y ago
    Yep - so it's kind of a check for "Am I overexcited about fusion energy?". Seems like it would be nice to have the fusion option if it works out but we can maybe get the same benefits promised by fusion from wind + solar + a few days of energy storage. Either way it doesn't seem like it will be truly revolutionary at this point - as you showed, our problems are bigger than just cheap/clean energy, and we do have seemingly viable options for that on the near horizon anyways without fusion. I'm pro-fusion, I'd like to see more resources allocated towards its development, but my outlook on its potential impact is very tempered.