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I sometimes wonder if we actually need Fusion right now. There's a big sun throwing it's energy at us all the time. Cost of ITER is gonna be around $20 billion

I sometimes wonder if we actually need Fusion right now. There's a big sun throwing it's energy at us all the time. Cost of ITER is gonna be around $20 billion. That's 8 Topaz solar stations, together putting out 10 TWh annually. That would give 1.5 San Franciscos electricity at the cost of maintenance/staffing.

runj__ 9y ago
"right now" - Probably not. But with something like fusion for free energy would could just start pulling carbon from the atmosphere, we could start to transmute elements, it would be great for interstellar travel and energy would be the limiting factor of a global AI.
- bewo001 9y ago
  Fusion power will be as 'free' as wind power. Both technologies struggle with high installation cost that has to be distributed over the number of customers and the lifetime of the plant. For fission power, the installation is already too high to compete with wind.
  - solarkraft 9y ago
    but fusion throws out lots of energy. the argument is that the energy will be very very cheap compared to the installation cost (because you just get so much).
    - bewo001 9y ago
      Fusion reactors also consume a lot of energy. ITER plans to have a gain factor of 10, making 500MW of heat -- not electricity -- out of 50MW. According to wikipedia, a gain factor of 22 would be needed for commercial operation. The record is a gain factor of 0.67.. If fusion will ever become economically viable is an open question.
      - Nomentatus 9y ago
        But that gain factor declines steeply if sunk costs decline, as they would for smaller reactors producing more energy per pound installed.
    - Robotbeat 9y ago
      Fission also throws out a lot of energy, and the plus side is it's much easier to get to work (which is also the drawback...). ...and that's a good point. After working on fusion for a while, fission certainly looks attractive! I mean, it just works! And for all the hemming and hawing about safety, it's actually remarkably safe (in real terms) compared to just about any other energy source.
rgbrenner 9y ago
which sounds like a lot until you remember that total world energy consumption is over 110,000 TWh. So using your numbers, you would need 88,000 topaz solar stations at a cost of $220 trillion. Makes ITER look like a drop in the bucket.
- RobLach 9y ago
  It doesn't get you anywhere to compare numbers between research and industry because ITER won't even generate electricity to the grid. I'm merely saying that if we have $20 billion laying around you can imagine the practical route of powering the Bay Area completely on renewables right now. How many $20 billion experiments are we away from fusion reaching those numbers? And also, why not expand Fission production. We have 5000 years of global energy powering Uranium fuel supply in the oceans. Power everything with nuclear and you have a cool 1000-2000 years of no scarcity to figure out Fusion.
  - solarkraft 9y ago
    Fission is crazy expensive to even start up, and with expensive safety mechanisms still a risk. Then you get to the expensive and very risky / guaranteed to leak long term storage of the very dangerous waste.
    - a_imho 9y ago
      What is the state of the art in fission that is already available?
    - 15charlimit 9y ago
      Fission is expensive to start up primarily due to regulation. Modern designs are extremely safe (fail-safe instead of fail-unsafe) and produce little in the way of dangerous waste. Politics is what killed fission.
  - deleted 9y ago
    [deleted]
blkhawk 9y ago
While we don't strictly need fusion it would be nice to have. We cannot easily generate all the power we need when and where we need it from renewables. we can generate a significant fraction of it tho. Plus for space based application fusion would be preferable.
perbu 9y ago
While it might not make sense for the grid there are other applications as well - like nuclear subs, battle cruisers and carriers.
nmeofthestate 9y ago
It seems to me we are in a desperate situation - we need to decarbonise energy, but so far have only made a tiny tiny scratch with intermittent, low-density renewables. So I don't get the sanguine attitude to whether we need fusion. It looks very much like we need something else, if we're ruling out fission.
DennisP 9y ago
The sun throws its energy at us all the time, but half the time there's a planet intercepting the catch. Cheap storage that scales far enough to run civilization isn't really a solved problem. We may solve it, but it's a research problem just like fusion is. Another possibility is to get the planet out of the way by putting our solar power stations in geosynchronous orbit. If SpaceX delivers on the extremely low launch cost they're promising for the BFR, this looks surprisingly economical with current solar power satellite designs; a good book about this is The Case for Space Solar Power: https://www.amazon.com/Case-Space-Solar-Power-ebook/dp/B00HNZ0Z96 https://www.amazon.com/Case-Space-Solar-Power-ebook/dp/B00HN...
- Robotbeat 9y ago
  Cheap storage is a vastly easier problem than cheap/sustainable fusion, though. I actually agree that space based solar power may make more sense than fusion, though. The path for space based solar power is through well-understood engineering. The path for fusion (while I'm certain it's possible) lies through less-well-understood plasma physics. Cheap storage is much easier than either problem, IMHO. We've already pretty much solved it to the extent needed for civilization, it's just not as cheap as our existing sources of industrial energy. But we're very close. If you actually spent significant time looking at what fusion and space based solar power require, then cheap storage looks much easier.
  - DennisP 9y ago
    Cheap storage doesn't look all that easy. None of our current technologies can pull it off; we simply run out of raw materials for existing battery technologies, and we're close to geographic limits for hydropower storage. There's research on new batteries using more abundant materials like sodium, but like many things, battery breakthroughs have a history of taking a long time to pan out. I read the above book cover to cover so you could say I've spent a decent amount of time looking into space solar. It's well worth a read. The early designs from the 1970s would have been hugely expensive even if launch were free, but new work since the late 90s has changed matters enormously. One key innovation is a change from a monolithic design to a self-assembling modular design, with a limited number of component types that are churned out in factories in large quantities. Another is retrodirective arrays, which use a ground signal to allow an array of small microwave transmitters to return a coherent focused beam to the signal source. The book estimates a retail cost of 15 cents/kWh; substituting the estimated BFR launch cost takes that down to 4.5 cents. Tokamak scaling laws are very well established at this point, and MIT's ARC design actually looks quite practical. The construction is modular, the inner wall is 3D printed and replaced annually, the coolant/blanket is FLiBe molten salt, and the whole thing is about ten times smaller than ITER with similar power output. The JET reactor is about the same size and was built in four years.
mcv 9y ago
> There's a big sun throwing it's energy at us all the time. That's the thing. Fusion energy research hasn't been paying off, solar energy research has. With the momentum solar currently has, it makes sense that everybody is betting on solar. Efficient fusion power would be absolutely fantastic, but I'll believe it when I see it.
- lulmerchant 9y ago
  Perhaps we've just been looking in the wrong place for it. Spending all this time in laboratories, when we had it all along in the centre of our solar system.

runj__ 9y ago

"right now" - Probably not. But with something like fusion for free energy would could just start pulling carbon from the atmosphere, we could start to transmute elements, it would be great for interstellar travel and energy would be the limiting factor of a global AI.

bewo001 9y ago
Fusion power will be as 'free' as wind power. Both technologies struggle with high installation cost that has to be distributed over the number of customers and the lifetime of the plant. For fission power, the installation is already too high to compete with wind.
- solarkraft 9y ago
  but fusion throws out lots of energy. the argument is that the energy will be very very cheap compared to the installation cost (because you just get so much).
  - bewo001 9y ago
    Fusion reactors also consume a lot of energy. ITER plans to have a gain factor of 10, making 500MW of heat -- not electricity -- out of 50MW. According to wikipedia, a gain factor of 22 would be needed for commercial operation. The record is a gain factor of 0.67.. If fusion will ever become economically viable is an open question.
    - Nomentatus 9y ago
      But that gain factor declines steeply if sunk costs decline, as they would for smaller reactors producing more energy per pound installed.
  - Robotbeat 9y ago
    Fission also throws out a lot of energy, and the plus side is it's much easier to get to work (which is also the drawback...). ...and that's a good point. After working on fusion for a while, fission certainly looks attractive! I mean, it just works! And for all the hemming and hawing about safety, it's actually remarkably safe (in real terms) compared to just about any other energy source.

rgbrenner 9y ago

which sounds like a lot until you remember that total world energy consumption is over 110,000 TWh. So using your numbers, you would need 88,000 topaz solar stations at a cost of $220 trillion. Makes ITER look like a drop in the bucket.

RobLach 9y ago
It doesn't get you anywhere to compare numbers between research and industry because ITER won't even generate electricity to the grid. I'm merely saying that if we have $20 billion laying around you can imagine the practical route of powering the Bay Area completely on renewables right now. How many $20 billion experiments are we away from fusion reaching those numbers? And also, why not expand Fission production. We have 5000 years of global energy powering Uranium fuel supply in the oceans. Power everything with nuclear and you have a cool 1000-2000 years of no scarcity to figure out Fusion.
- solarkraft 9y ago
  Fission is crazy expensive to even start up, and with expensive safety mechanisms still a risk. Then you get to the expensive and very risky / guaranteed to leak long term storage of the very dangerous waste.
  - a_imho 9y ago
    What is the state of the art in fission that is already available?
  - 15charlimit 9y ago
    Fission is expensive to start up primarily due to regulation. Modern designs are extremely safe (fail-safe instead of fail-unsafe) and produce little in the way of dangerous waste. Politics is what killed fission.
- deleted 9y ago
  [deleted]

blkhawk 9y ago

While we don't strictly need fusion it would be nice to have. We cannot easily generate all the power we need when and where we need it from renewables. we can generate a significant fraction of it tho. Plus for space based application fusion would be preferable.

perbu 9y ago

While it might not make sense for the grid there are other applications as well - like nuclear subs, battle cruisers and carriers.

nmeofthestate 9y ago

It seems to me we are in a desperate situation - we need to decarbonise energy, but so far have only made a tiny tiny scratch with intermittent, low-density renewables. So I don't get the sanguine attitude to whether we need fusion. It looks very much like we need something else, if we're ruling out fission.

DennisP 9y ago

The sun throws its energy at us all the time, but half the time there's a planet intercepting the catch. Cheap storage that scales far enough to run civilization isn't really a solved problem. We may solve it, but it's a research problem just like fusion is. Another possibility is to get the planet out of the way by putting our solar power stations in geosynchronous orbit. If SpaceX delivers on the extremely low launch cost they're promising for the BFR, this looks surprisingly economical with current solar power satellite designs; a good book about this is The Case for Space Solar Power: https://www.amazon.com/Case-Space-Solar-Power-ebook/dp/B00HNZ0Z96 https://www.amazon.com/Case-Space-Solar-Power-ebook/dp/B00HN...

Robotbeat 9y ago
Cheap storage is a vastly easier problem than cheap/sustainable fusion, though. I actually agree that space based solar power may make more sense than fusion, though. The path for space based solar power is through well-understood engineering. The path for fusion (while I'm certain it's possible) lies through less-well-understood plasma physics. Cheap storage is much easier than either problem, IMHO. We've already pretty much solved it to the extent needed for civilization, it's just not as cheap as our existing sources of industrial energy. But we're very close. If you actually spent significant time looking at what fusion and space based solar power require, then cheap storage looks much easier.
- DennisP 9y ago
  Cheap storage doesn't look all that easy. None of our current technologies can pull it off; we simply run out of raw materials for existing battery technologies, and we're close to geographic limits for hydropower storage. There's research on new batteries using more abundant materials like sodium, but like many things, battery breakthroughs have a history of taking a long time to pan out. I read the above book cover to cover so you could say I've spent a decent amount of time looking into space solar. It's well worth a read. The early designs from the 1970s would have been hugely expensive even if launch were free, but new work since the late 90s has changed matters enormously. One key innovation is a change from a monolithic design to a self-assembling modular design, with a limited number of component types that are churned out in factories in large quantities. Another is retrodirective arrays, which use a ground signal to allow an array of small microwave transmitters to return a coherent focused beam to the signal source. The book estimates a retail cost of 15 cents/kWh; substituting the estimated BFR launch cost takes that down to 4.5 cents. Tokamak scaling laws are very well established at this point, and MIT's ARC design actually looks quite practical. The construction is modular, the inner wall is 3D printed and replaced annually, the coolant/blanket is FLiBe molten salt, and the whole thing is about ten times smaller than ITER with similar power output. The JET reactor is about the same size and was built in four years.

mcv 9y ago

> There's a big sun throwing it's energy at us all the time. That's the thing. Fusion energy research hasn't been paying off, solar energy research has. With the momentum solar currently has, it makes sense that everybody is betting on solar. Efficient fusion power would be absolutely fantastic, but I'll believe it when I see it.

lulmerchant 9y ago
Perhaps we've just been looking in the wrong place for it. Spending all this time in laboratories, when we had it all along in the centre of our solar system.