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If we got to the point where cost wasn't a factor would the carbon footprint be extremely low? I assume at some point we'll be unable to ignore climate change a

If we got to the point where cost wasn't a factor would the carbon footprint be extremely low? I assume at some point we'll be unable to ignore climate change and our survival will depended on minimizing it using large amounts of energy from a source that doesn't have a high carbon footprint.

Terr_ 5y ago
If only ~30% of CO2 emissions are from power-plants (at least in the US, probably higher globally considering developing nations) then replacing those installations with fusion won't directly zero things out... ... But if "cost wasn't a factor" then we could just simply dedicate the electrical output of fusion plants to brute-force CO2 out of the air.
- parineum 5y ago
  If fusion drives electricity prices into the ground, transportation is going to rapidly go electric.
  - ben_w 5y ago
    PV is already driving electricity prices into the ground, the limiting factor right now is that batteries are expensive enough that long-term savings aren’t enough to overcome the sticker-price shock at the point of sale.
aaronblohowiak 5y ago
Yes. The reactor could more than pull out the carbon equivalent to its manufacture and then many many times more.
godelski 5y ago
If cost wasn't a factor to any energy technology then you could probably negate its carbon footprint because you could use that electricity to cheaply pull carbon from the air. But there are other environmental impacts. Fusion, even compared to fission, has an extremely small footprint (per megawatt). Its fuel is easily available (isotopes of hydrogen). It does require some pretty advanced magnets though, so it will contribute to the strip mining that we do for rare earth materials (though this applies to all energy forms, including solar and wind). I don't have numbers to say if a fusion reactor would use less total rare earth metals per megawatt compared to something like solar or wind. One thing to note though. Once we get sustainable fusion reactors, it will still take a bit for that cost to come down significantly. That usually takes 10-20 years. This is a pretty common pattern. We've seen it from the price of laptops and cellphones to the price of solar panels.

Terr_ 5y ago

If only ~30% of CO2 emissions are from power-plants (at least in the US, probably higher globally considering developing nations) then replacing those installations with fusion won't directly zero things out... ... But if "cost wasn't a factor" then we could just simply dedicate the electrical output of fusion plants to brute-force CO2 out of the air.

parineum 5y ago
If fusion drives electricity prices into the ground, transportation is going to rapidly go electric.
- ben_w 5y ago
  PV is already driving electricity prices into the ground, the limiting factor right now is that batteries are expensive enough that long-term savings aren’t enough to overcome the sticker-price shock at the point of sale.

aaronblohowiak 5y ago

Yes. The reactor could more than pull out the carbon equivalent to its manufacture and then many many times more.

godelski 5y ago

If cost wasn't a factor to any energy technology then you could probably negate its carbon footprint because you could use that electricity to cheaply pull carbon from the air. But there are other environmental impacts. Fusion, even compared to fission, has an extremely small footprint (per megawatt). Its fuel is easily available (isotopes of hydrogen). It does require some pretty advanced magnets though, so it will contribute to the strip mining that we do for rare earth materials (though this applies to all energy forms, including solar and wind). I don't have numbers to say if a fusion reactor would use less total rare earth metals per megawatt compared to something like solar or wind. One thing to note though. Once we get sustainable fusion reactors, it will still take a bit for that cost to come down significantly. That usually takes 10-20 years. This is a pretty common pattern. We've seen it from the price of laptops and cellphones to the price of solar panels.