4 ms·

Completely agree with the outlook ("fusion power irrelevant for climate change in every realistic scenario"). But where did you take those grid cost numbers fr

Completely agree with the outlook ("fusion power irrelevant for climate change in every realistic scenario"). But where did you take those grid cost numbers from? Iter costs are <100bn AFAIC; and Germany alone (!!) projects more than that (top end) for grid expansion/operation within 2040 (mainly north/south and offshore connectivity).

ben_w 8mo ago
Putting this note first, because it's probably the main point of confusion/surprise: I did say "bill of materials"; the estimated full cost for European and US grid upgrades that we need anyway for other reasons, with far less material, is order-of a trillion or so for US, half a trillion for EU. For the material cost, just applied maths. By sheer coincidence, 1Ω of aluminium around the world is very close to 1m^2 cross section: https://www.wolframalpha.com/input?i=40000km+*+resistance+aluminium+%2F+1m%5E2 https://www.wolframalpha.com/input?i=40000km+*+resistance+al... This is almost exactly 1e8 (100 million) tons: https://www.wolframalpha.com/input?i=40000km+*+1m%5E2+*+density+aluminium https://www.wolframalpha.com/input?i=40000km+*+1m%5E2+*+dens... This is $223bn at current prices: https://www.wolframalpha.com/input?i=40000km+*+1m%5E2+*+density+aluminium+*+price+aluminium https://www.wolframalpha.com/input?i=40000km+*+1m%5E2+*+dens... For scale, this is about what China makes in 2 years; if this is rolled out over 30, which would be optimistic but plausible, it's within the realm of just how much China increased production between 2023 and 2025, being spent every year. To get to 10x ITER's own estimate for ITER, the wikipedia page says the organisation estimates the reactor will cost about €18-22bn: https://en.wikipedia.org/wiki/ITER https://en.wikipedia.org/wiki/ITER There are a lot of reasons not to do this as a single big 1m^2 "wire", amongst them being that the surface magnetic field is strong enough to be dangerous to approach with ferrous materials.
- myrmidon 8mo ago
  The "square meter of aluminium" is an interesting take. Not sure how much power you'd get over that thing; extrapolating from existing HVDC systems (Inga-Shaba is 1GW over 2x520mm²), I'd expect around 1TW, so twice the US demand? But because Nimbys have no appreciation for beautiful pylons, projects in that direction are doomed for now anyway and everything needs to be buried underground at extra cost :(
  - ben_w 8mo ago
    Losses are I^2 R, which has the annoying consequence that % loss depends on how much juice you put through it, it isn't a constant percentage. Pylons… eh. Doing this realistically rather than my napkin-maths, it would be a mix of many different solutions in different parts of the world, from competing environmental issues. Some would be pylons, some underground cables. Is the Sahara dry enough to run it on the ground, or in a concrete trench? I have no idea. As a side note, every so often I keep being surprised on here by Americans who can't rely on the grid in winter because snow disables it, and some Californian forest fires are attributed to unmaintained pylons failing, dropping live wires onto the forest where they spark and light up the dry wood. These could both be resolved by burying more cables. Likewise within urban areas: here in Europe it's rather rare to see overhead lines in urban or suburban areas, unless they're over a tram/railway line. IMO the real killer of any project like this, is geopolitics, not local politics. EU doesn't trust China, the US, or Russia; the current US administration doesn't trust or doesn't like basically everyone; Russia kinda gets along with China but few else; China would like to sell stuff to everyone but also have border disputes and other friction with many of their neighbours.
    - myrmidon 8mo ago
      I do agree that politics is a big enemy here (with nations historically being most willing to spend big on energy when reducing interdependence, like the french Messmer plan, instead of the reverse). Honestly the "1m² around the world" is probably a pretty good proxy for what we would need to solve intermittency problems exclusively by boosting grid connectivity (instead of storage), rescaling this to 4m² cumulative cross-section could probably transport the total global electrical energy consumption over ~10000km (but the losses would get uncomfortably high from an economical point of view after crossing the 1000-2000km distance threshold, so you might want even more aluminium when you desire connections that long). Btw: Underground cables instead of pylons are absolutely a nimby thing. Not only is it much more expensive, because you pay for the earthwork and additional insulator, but it also limits your voltage (to avoid overpaying for insulation even more). Return current is typically free, either from balancing 3phase AC or because decent electrodes get you <1Ohm over any distance thanks to math for the DC case. Just talking high voltage here; for short range, lower power residential connections the situation is different.

ben_w 8mo ago

Putting this note first, because it's probably the main point of confusion/surprise: I did say "bill of materials"; the estimated full cost for European and US grid upgrades that we need anyway for other reasons, with far less material, is order-of a trillion or so for US, half a trillion for EU. For the material cost, just applied maths. By sheer coincidence, 1Ω of aluminium around the world is very close to 1m^2 cross section: https://www.wolframalpha.com/input?i=40000km+*+resistance+aluminium+%2F+1m%5E2 https://www.wolframalpha.com/input?i=40000km+*+resistance+al... This is almost exactly 1e8 (100 million) tons: https://www.wolframalpha.com/input?i=40000km+*+1m%5E2+*+density+aluminium https://www.wolframalpha.com/input?i=40000km+*+1m%5E2+*+dens... This is $223bn at current prices: https://www.wolframalpha.com/input?i=40000km+*+1m%5E2+*+density+aluminium+*+price+aluminium https://www.wolframalpha.com/input?i=40000km+*+1m%5E2+*+dens... For scale, this is about what China makes in 2 years; if this is rolled out over 30, which would be optimistic but plausible, it's within the realm of just how much China increased production between 2023 and 2025, being spent every year. To get to 10x ITER's own estimate for ITER, the wikipedia page says the organisation estimates the reactor will cost about €18-22bn: https://en.wikipedia.org/wiki/ITER https://en.wikipedia.org/wiki/ITER There are a lot of reasons not to do this as a single big 1m^2 "wire", amongst them being that the surface magnetic field is strong enough to be dangerous to approach with ferrous materials.

myrmidon 8mo ago
The "square meter of aluminium" is an interesting take. Not sure how much power you'd get over that thing; extrapolating from existing HVDC systems (Inga-Shaba is 1GW over 2x520mm²), I'd expect around 1TW, so twice the US demand? But because Nimbys have no appreciation for beautiful pylons, projects in that direction are doomed for now anyway and everything needs to be buried underground at extra cost :(
- ben_w 8mo ago
  Losses are I^2 R, which has the annoying consequence that % loss depends on how much juice you put through it, it isn't a constant percentage. Pylons… eh. Doing this realistically rather than my napkin-maths, it would be a mix of many different solutions in different parts of the world, from competing environmental issues. Some would be pylons, some underground cables. Is the Sahara dry enough to run it on the ground, or in a concrete trench? I have no idea. As a side note, every so often I keep being surprised on here by Americans who can't rely on the grid in winter because snow disables it, and some Californian forest fires are attributed to unmaintained pylons failing, dropping live wires onto the forest where they spark and light up the dry wood. These could both be resolved by burying more cables. Likewise within urban areas: here in Europe it's rather rare to see overhead lines in urban or suburban areas, unless they're over a tram/railway line. IMO the real killer of any project like this, is geopolitics, not local politics. EU doesn't trust China, the US, or Russia; the current US administration doesn't trust or doesn't like basically everyone; Russia kinda gets along with China but few else; China would like to sell stuff to everyone but also have border disputes and other friction with many of their neighbours.
  - myrmidon 8mo ago
    I do agree that politics is a big enemy here (with nations historically being most willing to spend big on energy when reducing interdependence, like the french Messmer plan, instead of the reverse). Honestly the "1m² around the world" is probably a pretty good proxy for what we would need to solve intermittency problems exclusively by boosting grid connectivity (instead of storage), rescaling this to 4m² cumulative cross-section could probably transport the total global electrical energy consumption over ~10000km (but the losses would get uncomfortably high from an economical point of view after crossing the 1000-2000km distance threshold, so you might want even more aluminium when you desire connections that long). Btw: Underground cables instead of pylons are absolutely a nimby thing. Not only is it much more expensive, because you pay for the earthwork and additional insulator, but it also limits your voltage (to avoid overpaying for insulation even more). Return current is typically free, either from balancing 3phase AC or because decent electrodes get you <1Ohm over any distance thanks to math for the DC case. Just talking high voltage here; for short range, lower power residential connections the situation is different.