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Thankfully, the planet contains abundant stores of Uranium.. and we are nowhere near peak efficiency in commercial and industrial processes. These one dimens

Thankfully, the planet contains abundant stores of Uranium.. and we are nowhere near peak efficiency in commercial and industrial processes. These one dimensional analysis of the problem are particularly useless, especially when their only conclusion is "we must stop growth." The average power usage may well be 2000W, but how many average consumers are there? If we're facing a multi-mode distribution of those users, then this "stop growth" strategy instantly creates new "castes" from this distribution. As a long term strategy, it seems doomed in one way or another.

api 4y ago
These analyses have been predicting doom for decades. They just keep moving the goal post.
- Arthur8 4y ago
  Huh, I had to re-read the article. "But let’s not overlook the key point: continued growth in energy use becomes physically impossible within conceivable timeframes." (conceivable timeframes ~ few 100 years) As far as I understood, the argument is not "we are doomed" but that there is a natural limit to the growth of energy consumption in the not too distant future using some naive assumptions. In any case, it is implying that 2.9% growth per year is a lot! if it is extrapolated by just a few 100 years. Do I misunderstand something? Why is this controversial? But I did not yet read all the linked later posts.
  - Jweb_Guru 4y ago
    You are correct.
  - ninjinxo 4y ago
    It's not profound to say that sustained (infinite) growth is unsustainable, but it is of interest when it's within a conceivable timeframe. It's not worth reading however, because the author whimsically extrapolates energy usage starting from 230 years before the invention of the lightbulb to get their exponential growth argument which doesn't hold at all for modern data. https://data.worldbank.org/indicator/EG.USE.ELEC.KH.PC?end=2014&locations=AU-XU&start=1960&view=chart&year=2022 https://data.worldbank.org/indicator/EG.USE.ELEC.KH.PC?end=2...
lumost 4y ago
The article accounts for this in average earth temperature. The earth’s surface would be hotter than the sun in 1000 years, and would generally be uncomfortable after 200. The only way around that would be a substantial change in the thermodynamic efficiency of our energy use and/or a non radiative means of disposing of heat. Granted, if we did have the equivalent energy of a sun - we are unlikely to be spending it all on earth. Escaping earths gravity would be a trivial expense.
- whatshisface 4y ago
  That thermodynamic argument was the least convincing part. If you wanted to, you could beam your power plant's infrared radiation towards space, or put the plant itself in space and have it beam its waste heat away from the planet. The idea that heat dissipation is limited by the black body radiation of the Earth assumes that your house is part of the power plant's radiator, which itself implies that you will be living in a power plant's radiator. :-)
  - betwixthewires 4y ago
    That's because you don't understand thermodynamics. You can't just put the power plant in space and keep the heat from generating the power away from the earth, because the heat gets created where the power is used to perform work. You have to avoid consuming any of that power on the earth entirely. And you can't just beam the waste heat from every process away from the surface of the earth, that violates the second law of thermodynamics. The heat exists because the energy performed work, you are keeping the energy organized by beaming it in any direction, so it is not waste heat, it is direct infrared from the energy you've produced. You can only do this by not actually using the energy for work. This makes the whole exercise of even producing the energy pointless. I think the biggest hole in the argument is the jump to 100% efficiency. we don't consume mor energy because we feel like it, we consume it because we need it, and a factor of 5 increase in efficiency would equate to a factor of 5 decrease in production of energy resources.
    - whatshisface 4y ago
AtlasBarfed 4y ago
Only a small fraction of Uranium is usable for fission without breeding. There is (IIRC from a LFTR youtube) 4-10x as much thorium as uranium. The other issue is most designs are solid fuel rod, and they waste a huge percentage of the fuel once "spent". Nuclear isn't price competitive with existing wind/solar, and any new nuclear project is 10-20 years away, and with wind/solar in substantial/active cost improvement and economies of scale, nuclear may never be competitive. I loved those LFTR presentations, and I would like to think a scalable LFTR solution could be made price competitive with wind/solar once it stabilizes, but right now probably not. LFTR can use thorium (still needs a fissile uranium starter plug), and can probably breed non-fissile uranium, I've heard it can breed existing nuclear waste into usable fuel as well. It uses 99% of the fuel according to the sales brochure, which I view as a massive huge advantage: it takes all the handwringing and NIMBY about waste storage out of the equation. IMO that should be a table stakes for any "new nuclear" design. It's basically meltdown proof with the plug, isn't pressurized, and somewaht self-regulating in temperature if I understand the neutron economy and expansion/contraction of salts. Also a "table stakes" aspect of any new nuclear project IMO. Scalability is probably the biggest path forward to competitive fission as well, the original MSR at ORNL was allegedly closet-sized. Massive concrete dome designs lend too much to boondoggle management and cost overruns. Scalability would enable nuclear to compete with the current kings of scalable power generation: wind and especially solar. Maybe pebble bed can get a lot of the same table stakes as LFTR. Maybe a LFTR could serve as an onsite fuel reprocessor for a more economical design if LFTR isn't broad market feasible. I'm not a nuclear engineer, I'm just a fan of the ultracool engineering and science. But the economics don't line up for nuclear currently.

api 4y ago

These analyses have been predicting doom for decades. They just keep moving the goal post.

Arthur8 4y ago
Huh, I had to re-read the article. "But let’s not overlook the key point: continued growth in energy use becomes physically impossible within conceivable timeframes." (conceivable timeframes ~ few 100 years) As far as I understood, the argument is not "we are doomed" but that there is a natural limit to the growth of energy consumption in the not too distant future using some naive assumptions. In any case, it is implying that 2.9% growth per year is a lot! if it is extrapolated by just a few 100 years. Do I misunderstand something? Why is this controversial? But I did not yet read all the linked later posts.
- Jweb_Guru 4y ago
  You are correct.
- ninjinxo 4y ago
  It's not profound to say that sustained (infinite) growth is unsustainable, but it is of interest when it's within a conceivable timeframe. It's not worth reading however, because the author whimsically extrapolates energy usage starting from 230 years before the invention of the lightbulb to get their exponential growth argument which doesn't hold at all for modern data. https://data.worldbank.org/indicator/EG.USE.ELEC.KH.PC?end=2014&locations=AU-XU&start=1960&view=chart&year=2022 https://data.worldbank.org/indicator/EG.USE.ELEC.KH.PC?end=2...

lumost 4y ago

The article accounts for this in average earth temperature. The earth’s surface would be hotter than the sun in 1000 years, and would generally be uncomfortable after 200. The only way around that would be a substantial change in the thermodynamic efficiency of our energy use and/or a non radiative means of disposing of heat. Granted, if we did have the equivalent energy of a sun - we are unlikely to be spending it all on earth. Escaping earths gravity would be a trivial expense.

whatshisface 4y ago
That thermodynamic argument was the least convincing part. If you wanted to, you could beam your power plant's infrared radiation towards space, or put the plant itself in space and have it beam its waste heat away from the planet. The idea that heat dissipation is limited by the black body radiation of the Earth assumes that your house is part of the power plant's radiator, which itself implies that you will be living in a power plant's radiator. :-)
- betwixthewires 4y ago
  That's because you don't understand thermodynamics. You can't just put the power plant in space and keep the heat from generating the power away from the earth, because the heat gets created where the power is used to perform work. You have to avoid consuming any of that power on the earth entirely. And you can't just beam the waste heat from every process away from the surface of the earth, that violates the second law of thermodynamics. The heat exists because the energy performed work, you are keeping the energy organized by beaming it in any direction, so it is not waste heat, it is direct infrared from the energy you've produced. You can only do this by not actually using the energy for work. This makes the whole exercise of even producing the energy pointless. I think the biggest hole in the argument is the jump to 100% efficiency. we don't consume mor energy because we feel like it, we consume it because we need it, and a factor of 5 increase in efficiency would equate to a factor of 5 decrease in production of energy resources.
  - whatshisface 4y ago

AtlasBarfed 4y ago

Only a small fraction of Uranium is usable for fission without breeding. There is (IIRC from a LFTR youtube) 4-10x as much thorium as uranium. The other issue is most designs are solid fuel rod, and they waste a huge percentage of the fuel once "spent". Nuclear isn't price competitive with existing wind/solar, and any new nuclear project is 10-20 years away, and with wind/solar in substantial/active cost improvement and economies of scale, nuclear may never be competitive. I loved those LFTR presentations, and I would like to think a scalable LFTR solution could be made price competitive with wind/solar once it stabilizes, but right now probably not. LFTR can use thorium (still needs a fissile uranium starter plug), and can probably breed non-fissile uranium, I've heard it can breed existing nuclear waste into usable fuel as well. It uses 99% of the fuel according to the sales brochure, which I view as a massive huge advantage: it takes all the handwringing and NIMBY about waste storage out of the equation. IMO that should be a table stakes for any "new nuclear" design. It's basically meltdown proof with the plug, isn't pressurized, and somewaht self-regulating in temperature if I understand the neutron economy and expansion/contraction of salts. Also a "table stakes" aspect of any new nuclear project IMO. Scalability is probably the biggest path forward to competitive fission as well, the original MSR at ORNL was allegedly closet-sized. Massive concrete dome designs lend too much to boondoggle management and cost overruns. Scalability would enable nuclear to compete with the current kings of scalable power generation: wind and especially solar. Maybe pebble bed can get a lot of the same table stakes as LFTR. Maybe a LFTR could serve as an onsite fuel reprocessor for a more economical design if LFTR isn't broad market feasible. I'm not a nuclear engineer, I'm just a fan of the ultracool engineering and science. But the economics don't line up for nuclear currently.