5 ms·

Yeah, really, how? Fusion power plants still need land, buildings, generators, switchyards, wire, own power consumption, environmental impact reports, planning

Yeah, really, how? Fusion power plants still need land, buildings, generators, switchyards, wire, own power consumption, environmental impact reports, planning permits, regulations, inspections, and all the rest. And they need exotic materials and weird engineering in their construction. Really: how does fusion get us to ~1% (correction: ~5%) of current power prices? I've never seen a convincing explanation. Usually it's bare assertion. Infrequently it's handwavium/unobtanium.

AnthonyMouse 5y ago
One of the big problems with existing power plants is that you have to build them near where people are. So then land is expensive and you get a bunch of regulations because people are worried about what's happening in their back yard. If you could hypothetically build a fusion plant that would generate several times more power than existing fission reactors at a similar construction cost, you would have so much power you wouldn't have to worry much about transmission losses. At which point you could put it in the middle of nowhere without those constraints and make it actually less expensive for several times more power. Then for cities power gets cheaper, but for anything that can be built out in the middle of nowhere near the reactor, power gets a lot cheaper.
- tuatoru 5y ago
  How is that reasoning specific to fusion? Unless fusion power is dramatically more efficient than other thermal plants, like 99.9%, your bigger plant will still need massive heat removal structures and systems, which means siting them near water. All the good spots are already taken. Alternatively you can use truly massive air heat transfer structures, driving up your construction costs again. I neglected to mention finance costs also. With an untried technology the rate of return demanded is going to be very high, further driving up project costs.
  - AnthonyMouse 5y ago
    > How is that reasoning specific to fusion? A major cost of the most utilized existing power plants (coal and natural gas) is fuel. If you build a natural gas plant which is twice as big so that you can put it out where the land is cheaper and eat the transmission losses, now you need twice as much natural gas. Renewables don't need fuel but their construction cost is fully linear, you get no economies of scale. If you want twice as many solar panels then you need twice as much land. If you want to double the size of your fusion reactor, you build an eight story building instead of a four story building on the same piece of land. > Unless fusion power is dramatically more efficient than other thermal plants, like 99.9%, your bigger plant will still need massive heat removal structures and systems, which means siting them near water. All the good spots are already taken. An obvious solution is to build them out in the ocean. Then you have plenty of water and you're still not near anything. And the good spots near population centers are already taken. Some lake a hundred miles from any city won't be. > I neglected to mention finance costs also. With an untried technology the rate of return demanded is going to be very high, further driving up project costs. That's only true for the first one. If it's hypothetically ten times more power for the same money, that'll get one built even at a high interest rate. Then once you have it running it's proven technology.
    - tuatoru 5y ago
      > A major cost of the most utilized existing power plants (coal and natural gas) is fuel. Coal is dead. The competition is PV, and to a lesser extent wind. > Renewables don't need fuel but their construction cost is fully linear, you get no economies of scale. If you want twice as many solar panels then you need twice as much land. Yes, and you use odd bits of land close to consumption sites, many of which will have simultaneous use for other purposes. Edit: the linearity is an advantage in that it enables mass production, and gets the benefit of the manufacturing learning curve. So your suggestion of overbuilding on cheap land a long way away from cities applies even more to PV. > If you want to double the size of your fusion reactor, you build an eight story building instead of a four story building on the same piece of land. Quadrupling your construction costs. Edit: mainly in the finance cost of the time taken. Also, making your generators much bigger than current practise increases project risk and therfore cost. > An obvious solution is to build them out in the ocean. Quadrupling your construction costs again, and decreasing reliability, capacity factor and productive lifetime. Seawater is nasty stuff. > And the good spots near population centers are already taken. Some big lake a hundred miles from any city won't be. It will be used for productive farmland, though. Again, why aren't fission or CCGT plants being built in those places? How is fusion different? > [High finance cost is] only true for the first one. If it's hypothetically ten times more power for the same money, that'll get one built even at a high interest rate. Then once you have it running it's proven technology. It's about time to cashflow for utility finance types, and they also tend to want a longer track record than "it worked once". The linearity/modularity of wind and PV is an advantage in the time to cashflow aspect. Edit: I haven't so far seen anything significant in your replies that doesn't also apply to fission. Utilty project financiers are hard-headed; they'll finance fission if it makes them enough money soon enough. You are fiddling around the edges rather than demonstrating an order of magnitude cost reduction from PV.
  - deleted 5y ago
    [deleted]
- ant6n 5y ago
  Again this assumes fusion power will be cheap. But in reality it may cost about as much as (fission) nuclear power. So yes it may help with making energy production carbon-free (together with solar, wind, hydro), but it won't necessarily create a some sort of energy abundance.
  - AnthonyMouse 5y ago
    The theory isn't that the cost will be low, it's that the output will be high. If it costs the same amount as a fission reactor but produces ten times more power, that's lower cost per MW than anything on the market. Even if it costs more than fission, it could be competitive as long as the more it costs is less than the more it outputs.
    - bildung 5y ago
      But how should that gain in energy output be possible without making the whole system huge, too? The heat generating part of a nuclear power station only makes up a small fraction, most of the material is for transforming the heat to electricity and to shield off radiation. If you want to process more heat, you need more infrastructure to do so.
    - jabl 5y ago
      But why would a fusion reactor produce 10 times more power than a fission reactor of the same cost? A fission reactor is, comparatively, very simple. Just a steel cylinder filled with fuel and control rods. No superconducting magnets, no zillion degree plasma to contain and control, low neutron field (as long as we're comparing to D-T fusion). Also heat transfer is much more efficient, enabling high power density, since you pump coolant through the entire reactor vessel instead of just the outer edges.
- regularfry 5y ago
  > One of the big problems with existing power plants is that you have to build them near where people are. I don't know how it works in the US, but this is notably not true in the UK and Europe. Gas plants are comparatively small and nestled in, but big coal (to a limited degree) and particularly fission plants are frequently in the middle of nowhere. They're somewhere near a village that can supply a workforce, but siting concerns for nukes were more based on making sure any criticality excitement could be shared with neighbours across whatever nearby border was handy than putting them anywhere near cities.
godelski 5y ago
Theoretically? Pure brute force. Fusion just generates that much electricity that it has the potential to be insanely profitable. There's a lot of ifs, but there's a good reason to bet big on it.
- tuatoru 5y ago
  Please explain how it generates that much electricity that cheaply. Direct conversion is theoretically about 60% thermally efficient, on par with combined cycle gas generators.
  - godelski 5y ago
    > Please explain how it generates that much electricity This is the non-theoretical part > that cheaply. This is the theoretical part. I think a lot of people are misinterpreting my comment. I have absolutely no idea if it can be done that cheaply. But I can say for a fact that the yield of energy is massive. The question is if it can be done cheaply. That's the bet. The question is if you want to take that bet. You have to make similar bets on tons of technologies. It usually takes 10-20 years after something is made till it starts to follow the S curve and become cheap. Even solar and wind followed this.
- tsimionescu 5y ago
  People often make the mistake of looking at the reaction energy of fusion, and comparing that with fission or burning fossil fuels. But the majority of the reaction energy is carried away by high-speed neutrons, which are pure waste - they can't be captured by magnetic fields, they are heavy and penetrate almost any material, leaving holes behind that make the structure brittle, and when they do get absorbed, they make the atom that absorbed them unstable, turning the material radioactive. So, at least as long as we use neutri-producing fusion (and any realistic fusion reactor has to) the actually usable energy is not that impressive compared to fission.
pjerem 5y ago
That’s about the same infrastructure than a nuclear fission reactor. And nuclear electricity is already pretty cheap. I don’t know how it costs in US, but in France, fully charging a Model 3 costs about ~5€ at night. That’s not 10x cheaper than gas but that’s a lot cheaper.
- olau 5y ago
  There are two problems with this reasoning. First, you are comparing the cost of written-off plants, for a technology that has huge upfront costs and much lower fuel costs. Fission is not cheap if you build a new nuclear plant, not in the Western world. That's why almost no nuclear plants are being build. Making a safe plant is just really, really complicated. Second, this specific argument can be used to see why fusion is a pipe dream. The primary competitor to fusion is fission. And the fuel costs of fission are pretty low, as you just said. So fusion will not be competitive unless you can built them around the same price as fission plants. Someone else in this thread talked about S curves. Well, those kind of S curves happen for tech that gets produced in larger quantities, where it is economical to spend engineering resources making the production of the tech cheaper.
  - pjerem 5y ago
    Maybe I’m wrong but fission also don’t need extreme cooling utilities. And fission seems to be way more secure than fusion. So, while I do agree on the « new tech » costs, I’m pretty confident we’ll be able to build this plants anywhere in the world and not only near rivers. But maybe I’m too optimistic :)
    - phreeza 5y ago
      I think you mixed up fission and fusion there. Regardless, a fusion reactor will need similar amount of cooling infrastructure if you want to output a similar amount of electricity.
- bildung 5y ago
  Retail electricity prices in France are €0,13/kWh, so not that cheap (€0,18/kWh pre pandemic). https://www.statista.com/statistics/418087/electricity-prices-for-households-in-france/ https://www.statista.com/statistics/418087/electricity-price... This doesn't matter, though, because France doesn't need many nukes anymore, therefore doesn't subsidizes new plants anymore. One new plant is built in France, and it already is hellishly expensive: "As of 2020 the project is more than five times over budget and years behind schedule. Various safety problems have been raised, including weakness in the steel used in the reactor." https://en.wikipedia.org/wiki/Flamanville_Nuclear_Power_Plant https://en.wikipedia.org/wiki/Flamanville_Nuclear_Power_Plan...

AnthonyMouse 5y ago

One of the big problems with existing power plants is that you have to build them near where people are. So then land is expensive and you get a bunch of regulations because people are worried about what's happening in their back yard. If you could hypothetically build a fusion plant that would generate several times more power than existing fission reactors at a similar construction cost, you would have so much power you wouldn't have to worry much about transmission losses. At which point you could put it in the middle of nowhere without those constraints and make it actually less expensive for several times more power. Then for cities power gets cheaper, but for anything that can be built out in the middle of nowhere near the reactor, power gets a lot cheaper.

tuatoru 5y ago
How is that reasoning specific to fusion? Unless fusion power is dramatically more efficient than other thermal plants, like 99.9%, your bigger plant will still need massive heat removal structures and systems, which means siting them near water. All the good spots are already taken. Alternatively you can use truly massive air heat transfer structures, driving up your construction costs again. I neglected to mention finance costs also. With an untried technology the rate of return demanded is going to be very high, further driving up project costs.
- AnthonyMouse 5y ago
  > How is that reasoning specific to fusion? A major cost of the most utilized existing power plants (coal and natural gas) is fuel. If you build a natural gas plant which is twice as big so that you can put it out where the land is cheaper and eat the transmission losses, now you need twice as much natural gas. Renewables don't need fuel but their construction cost is fully linear, you get no economies of scale. If you want twice as many solar panels then you need twice as much land. If you want to double the size of your fusion reactor, you build an eight story building instead of a four story building on the same piece of land. > Unless fusion power is dramatically more efficient than other thermal plants, like 99.9%, your bigger plant will still need massive heat removal structures and systems, which means siting them near water. All the good spots are already taken. An obvious solution is to build them out in the ocean. Then you have plenty of water and you're still not near anything. And the good spots near population centers are already taken. Some lake a hundred miles from any city won't be. > I neglected to mention finance costs also. With an untried technology the rate of return demanded is going to be very high, further driving up project costs. That's only true for the first one. If it's hypothetically ten times more power for the same money, that'll get one built even at a high interest rate. Then once you have it running it's proven technology.
  - tuatoru 5y ago
    > A major cost of the most utilized existing power plants (coal and natural gas) is fuel. Coal is dead. The competition is PV, and to a lesser extent wind. > Renewables don't need fuel but their construction cost is fully linear, you get no economies of scale. If you want twice as many solar panels then you need twice as much land. Yes, and you use odd bits of land close to consumption sites, many of which will have simultaneous use for other purposes. Edit: the linearity is an advantage in that it enables mass production, and gets the benefit of the manufacturing learning curve. So your suggestion of overbuilding on cheap land a long way away from cities applies even more to PV. > If you want to double the size of your fusion reactor, you build an eight story building instead of a four story building on the same piece of land. Quadrupling your construction costs. Edit: mainly in the finance cost of the time taken. Also, making your generators much bigger than current practise increases project risk and therfore cost. > An obvious solution is to build them out in the ocean. Quadrupling your construction costs again, and decreasing reliability, capacity factor and productive lifetime. Seawater is nasty stuff. > And the good spots near population centers are already taken. Some big lake a hundred miles from any city won't be. It will be used for productive farmland, though. Again, why aren't fission or CCGT plants being built in those places? How is fusion different? > [High finance cost is] only true for the first one. If it's hypothetically ten times more power for the same money, that'll get one built even at a high interest rate. Then once you have it running it's proven technology. It's about time to cashflow for utility finance types, and they also tend to want a longer track record than "it worked once". The linearity/modularity of wind and PV is an advantage in the time to cashflow aspect. Edit: I haven't so far seen anything significant in your replies that doesn't also apply to fission. Utilty project financiers are hard-headed; they'll finance fission if it makes them enough money soon enough. You are fiddling around the edges rather than demonstrating an order of magnitude cost reduction from PV.
- deleted 5y ago
  [deleted]
ant6n 5y ago
Again this assumes fusion power will be cheap. But in reality it may cost about as much as (fission) nuclear power. So yes it may help with making energy production carbon-free (together with solar, wind, hydro), but it won't necessarily create a some sort of energy abundance.
- AnthonyMouse 5y ago
  The theory isn't that the cost will be low, it's that the output will be high. If it costs the same amount as a fission reactor but produces ten times more power, that's lower cost per MW than anything on the market. Even if it costs more than fission, it could be competitive as long as the more it costs is less than the more it outputs.
  - bildung 5y ago
    But how should that gain in energy output be possible without making the whole system huge, too? The heat generating part of a nuclear power station only makes up a small fraction, most of the material is for transforming the heat to electricity and to shield off radiation. If you want to process more heat, you need more infrastructure to do so.
  - jabl 5y ago
    But why would a fusion reactor produce 10 times more power than a fission reactor of the same cost? A fission reactor is, comparatively, very simple. Just a steel cylinder filled with fuel and control rods. No superconducting magnets, no zillion degree plasma to contain and control, low neutron field (as long as we're comparing to D-T fusion). Also heat transfer is much more efficient, enabling high power density, since you pump coolant through the entire reactor vessel instead of just the outer edges.
regularfry 5y ago
> One of the big problems with existing power plants is that you have to build them near where people are. I don't know how it works in the US, but this is notably not true in the UK and Europe. Gas plants are comparatively small and nestled in, but big coal (to a limited degree) and particularly fission plants are frequently in the middle of nowhere. They're somewhere near a village that can supply a workforce, but siting concerns for nukes were more based on making sure any criticality excitement could be shared with neighbours across whatever nearby border was handy than putting them anywhere near cities.

godelski 5y ago

Theoretically? Pure brute force. Fusion just generates that much electricity that it has the potential to be insanely profitable. There's a lot of ifs, but there's a good reason to bet big on it.

tuatoru 5y ago
Please explain how it generates that much electricity that cheaply. Direct conversion is theoretically about 60% thermally efficient, on par with combined cycle gas generators.
- godelski 5y ago
  > Please explain how it generates that much electricity This is the non-theoretical part > that cheaply. This is the theoretical part. I think a lot of people are misinterpreting my comment. I have absolutely no idea if it can be done that cheaply. But I can say for a fact that the yield of energy is massive. The question is if it can be done cheaply. That's the bet. The question is if you want to take that bet. You have to make similar bets on tons of technologies. It usually takes 10-20 years after something is made till it starts to follow the S curve and become cheap. Even solar and wind followed this.
tsimionescu 5y ago
People often make the mistake of looking at the reaction energy of fusion, and comparing that with fission or burning fossil fuels. But the majority of the reaction energy is carried away by high-speed neutrons, which are pure waste - they can't be captured by magnetic fields, they are heavy and penetrate almost any material, leaving holes behind that make the structure brittle, and when they do get absorbed, they make the atom that absorbed them unstable, turning the material radioactive. So, at least as long as we use neutri-producing fusion (and any realistic fusion reactor has to) the actually usable energy is not that impressive compared to fission.

pjerem 5y ago

That’s about the same infrastructure than a nuclear fission reactor. And nuclear electricity is already pretty cheap. I don’t know how it costs in US, but in France, fully charging a Model 3 costs about ~5€ at night. That’s not 10x cheaper than gas but that’s a lot cheaper.

olau 5y ago
There are two problems with this reasoning. First, you are comparing the cost of written-off plants, for a technology that has huge upfront costs and much lower fuel costs. Fission is not cheap if you build a new nuclear plant, not in the Western world. That's why almost no nuclear plants are being build. Making a safe plant is just really, really complicated. Second, this specific argument can be used to see why fusion is a pipe dream. The primary competitor to fusion is fission. And the fuel costs of fission are pretty low, as you just said. So fusion will not be competitive unless you can built them around the same price as fission plants. Someone else in this thread talked about S curves. Well, those kind of S curves happen for tech that gets produced in larger quantities, where it is economical to spend engineering resources making the production of the tech cheaper.
- pjerem 5y ago
  Maybe I’m wrong but fission also don’t need extreme cooling utilities. And fission seems to be way more secure than fusion. So, while I do agree on the « new tech » costs, I’m pretty confident we’ll be able to build this plants anywhere in the world and not only near rivers. But maybe I’m too optimistic :)
  - phreeza 5y ago
    I think you mixed up fission and fusion there. Regardless, a fusion reactor will need similar amount of cooling infrastructure if you want to output a similar amount of electricity.
bildung 5y ago
Retail electricity prices in France are €0,13/kWh, so not that cheap (€0,18/kWh pre pandemic). https://www.statista.com/statistics/418087/electricity-prices-for-households-in-france/ https://www.statista.com/statistics/418087/electricity-price... This doesn't matter, though, because France doesn't need many nukes anymore, therefore doesn't subsidizes new plants anymore. One new plant is built in France, and it already is hellishly expensive: "As of 2020 the project is more than five times over budget and years behind schedule. Various safety problems have been raised, including weakness in the steel used in the reactor." https://en.wikipedia.org/wiki/Flamanville_Nuclear_Power_Plant https://en.wikipedia.org/wiki/Flamanville_Nuclear_Power_Plan...