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Articbull is saying nuclear is better than solar for the energy system. He bases this on a claim that solar panels are inefficient along a number of dimensions.

Articbull is saying nuclear is better than solar for the energy system. He bases this on a claim that solar panels are inefficient along a number of dimensions. Look at his actual comments, they aren’t narrowly related to lab or theoretical efficiency (he is making points about land use, death, etc). There is no real concept of physical inefficiency there is only relative efficiency. And relative efficiency of Rankine cycle prime movers vs semiconductors is not a strictly easy comparison. 20% of something free that would have been entirely wasted is different than 40% of something you have to find, dig out, transport, crush, then filter. I also didn’t say what he said about theoretical panel efficiency is wrong (except all his actual numbers were wrong until he edited them). I am broadly saying this point doesn’t support his conclusion. Edit: you are also wrong about what happens to the energy that hits the panel. Some light is reflected, a lot of light passes right through the panel. Further, panels are designed for particular wavelengths which is why multi gap panels have theoretical efficiencies higher than any thermal plant. And some is turned into heat. All of this would have happened had the panel not been there too except no usable electricity would be created.

fluoridation 4y ago
> Look at his actual comments, they aren’t narrowly related to lab or theoretical efficiency (he is making points about land use, death, etc). I don't know about deaths, but the point about land use is related to theoretical efficiency. If an existing solar plant that is 20% was 100% efficient it could generate five times as much power in the same space, or generate the same power in a fifth of the land it currently uses. The land used by solar power plants is very relevant when considering its practical utility. > 20% of something free that would have been entirely wasted is different than 40% of something you have to find, dig out, transport, crush, then filter. It's not free, though, because those rooftop panels will lose efficiency over time. Eventually they will need to be replaced or they will generate so little power that they may as well not be there. Since they need to be replaced over time then harvesting that 20% of sunlight is no longer free, but carries an ongoing resource cost. Is that more or less than the cost of getting the same total energy from a nuclear power plant? > I am broadly saying this point doesn’t support his conclusion. The conclusion is that solar and wind can at best only complement nuclear, and this is supported by various points about the inefficiency of solar panels. Setting wind aside for the moment, why do you think the fact that solar panels are inefficient and degrade over time doesn't affect their viability as an alternative to nuclear power? Response to edit: I don't know whether the 20% figure counts in the theoretical 100% light that is reflected or unabsorbed. It seems to me that it shouldn't be counted, since if you're going to count light that couldn't have interacted with the cells anyway, then you may as well count light that hits the ground next to the panel, which would mean the panel is 0% efficient.
- dpierce9 4y ago
  If nuclear plants were twice as efficient that would be great too. They aren’t. Land use isn’t relevant for rooftop solar. There is basically no opportunity cost. Everything becomes less efficient over time. Sunpower warranties their panels for a 20% decline in performance over 25 years. That means a 20% efficient panel is warrantied to be 16% efficient after 25 years in the field. To put that in perspective, panels made 15 years ago were around 16% efficient. There isn’t a cliff and they are still useful. Suppose you abandon the system for whatever reason. You go back to the steady state of not producing power on that site. There is again no cost. I am not saying nuclear is bad. I am outright rejecting the claim that solar panels are inefficient on any dimension that counts. I think this argument about degradation is beyond silly. I also think you are an astroturfing troll.
  - fluoridation 4y ago
    If you're going to assume bad faith then there's no point to the discussion.
    - dpierce9 4y ago
      I didn’t assume. I think you demonstrated. I agree there is no point.
- shmeeed 4y ago
  >Eventually they will need to be replaced or they will generate so little power that they may as well not be there. Since they need to be replaced over time then harvesting that 20% of sunlight is no longer free, but carries an ongoing resource cost. Is that more or less than the cost of getting the same total energy from a nuclear power plant? Yeah, is it more or less? I don't know either. But finally we're getting to the core of the question instead of debating about the number of angels that can dance on the head of a pin. So at the end of its lifetime, be that 50 or 100 years in, a nuclear plant will have to be replaced, too. Basically a sudden 100% degradation. What is the resource cost for that, why are we not talking about that in this context? Because it's not "ongoing"? What's the resource cost for cooling with increasingly sparse water bodies that due to climate change will be less and less suited for it over the lifespan of the plant, BTW degrading its efficiency? What's the resource cost of plant dismantling and disposal, which goes on for decades after a plant has ceased to produce power? Would you like to include nuclear waste disposal as an ongoing resource cost in the consideration? Where do you draw the line? Are there any reliable estimates about these externalities that don't range wildly depending on which faction informed them? Do we want go down that rabbit hole? If not, then what's the point of fixating on this single aspect with regards to solar and solar only? Just because this one is a figure that's easy to quote out of context and sounds kinda bad? Can I make you realize that in this light it's hard to not think of this as deliberately cherry-picking an argument for argument's sake? These are all retorical questions, of course. FWIW, I don't claim to have any definite answers on the topic, and actually I do think that nuclear and renewables will have to complement each other to varying degrees around the globe, depending on many factors. I'm just trying to get across why the specific point your're clinging to seems so extremely moot to me. >Setting wind aside for the moment, why do you think the fact that solar panels are inefficient and degrade over time doesn't affect their viability as an alternative to nuclear power? Because it's already correctly priced into the running costs, just as - I suppose its proponents will claim - the corresponding facts above are for nuclear. Also, as has been pointed out, the ever repeated claim of solar inefficiency is baseless in the most literal sense, due to the lack of a comparable reference point for nuclear. 20% is an entirely meaningless number as long as the system boundaries are drawn so arbitrarily that it's impossible to benchmark. To put it bluntly, what would be sufficiently efficient for your taste? 30%? 60? 90? Can you explain why? It's just apples and pears on this level, the only reasonable comparison could come from a much broader view that you're explicitly not interested in. Anyway this discussion is going in circles. I'm not assuming bad faith on your side, but I don't think we'll come to an agreement either.

fluoridation 4y ago

> Look at his actual comments, they aren’t narrowly related to lab or theoretical efficiency (he is making points about land use, death, etc). I don't know about deaths, but the point about land use is related to theoretical efficiency. If an existing solar plant that is 20% was 100% efficient it could generate five times as much power in the same space, or generate the same power in a fifth of the land it currently uses. The land used by solar power plants is very relevant when considering its practical utility. > 20% of something free that would have been entirely wasted is different than 40% of something you have to find, dig out, transport, crush, then filter. It's not free, though, because those rooftop panels will lose efficiency over time. Eventually they will need to be replaced or they will generate so little power that they may as well not be there. Since they need to be replaced over time then harvesting that 20% of sunlight is no longer free, but carries an ongoing resource cost. Is that more or less than the cost of getting the same total energy from a nuclear power plant? > I am broadly saying this point doesn’t support his conclusion. The conclusion is that solar and wind can at best only complement nuclear, and this is supported by various points about the inefficiency of solar panels. Setting wind aside for the moment, why do you think the fact that solar panels are inefficient and degrade over time doesn't affect their viability as an alternative to nuclear power? Response to edit: I don't know whether the 20% figure counts in the theoretical 100% light that is reflected or unabsorbed. It seems to me that it shouldn't be counted, since if you're going to count light that couldn't have interacted with the cells anyway, then you may as well count light that hits the ground next to the panel, which would mean the panel is 0% efficient.

dpierce9 4y ago
If nuclear plants were twice as efficient that would be great too. They aren’t. Land use isn’t relevant for rooftop solar. There is basically no opportunity cost. Everything becomes less efficient over time. Sunpower warranties their panels for a 20% decline in performance over 25 years. That means a 20% efficient panel is warrantied to be 16% efficient after 25 years in the field. To put that in perspective, panels made 15 years ago were around 16% efficient. There isn’t a cliff and they are still useful. Suppose you abandon the system for whatever reason. You go back to the steady state of not producing power on that site. There is again no cost. I am not saying nuclear is bad. I am outright rejecting the claim that solar panels are inefficient on any dimension that counts. I think this argument about degradation is beyond silly. I also think you are an astroturfing troll.
- fluoridation 4y ago
  If you're going to assume bad faith then there's no point to the discussion.
  - dpierce9 4y ago
    I didn’t assume. I think you demonstrated. I agree there is no point.
shmeeed 4y ago
>Eventually they will need to be replaced or they will generate so little power that they may as well not be there. Since they need to be replaced over time then harvesting that 20% of sunlight is no longer free, but carries an ongoing resource cost. Is that more or less than the cost of getting the same total energy from a nuclear power plant? Yeah, is it more or less? I don't know either. But finally we're getting to the core of the question instead of debating about the number of angels that can dance on the head of a pin. So at the end of its lifetime, be that 50 or 100 years in, a nuclear plant will have to be replaced, too. Basically a sudden 100% degradation. What is the resource cost for that, why are we not talking about that in this context? Because it's not "ongoing"? What's the resource cost for cooling with increasingly sparse water bodies that due to climate change will be less and less suited for it over the lifespan of the plant, BTW degrading its efficiency? What's the resource cost of plant dismantling and disposal, which goes on for decades after a plant has ceased to produce power? Would you like to include nuclear waste disposal as an ongoing resource cost in the consideration? Where do you draw the line? Are there any reliable estimates about these externalities that don't range wildly depending on which faction informed them? Do we want go down that rabbit hole? If not, then what's the point of fixating on this single aspect with regards to solar and solar only? Just because this one is a figure that's easy to quote out of context and sounds kinda bad? Can I make you realize that in this light it's hard to not think of this as deliberately cherry-picking an argument for argument's sake? These are all retorical questions, of course. FWIW, I don't claim to have any definite answers on the topic, and actually I do think that nuclear and renewables will have to complement each other to varying degrees around the globe, depending on many factors. I'm just trying to get across why the specific point your're clinging to seems so extremely moot to me. >Setting wind aside for the moment, why do you think the fact that solar panels are inefficient and degrade over time doesn't affect their viability as an alternative to nuclear power? Because it's already correctly priced into the running costs, just as - I suppose its proponents will claim - the corresponding facts above are for nuclear. Also, as has been pointed out, the ever repeated claim of solar inefficiency is baseless in the most literal sense, due to the lack of a comparable reference point for nuclear. 20% is an entirely meaningless number as long as the system boundaries are drawn so arbitrarily that it's impossible to benchmark. To put it bluntly, what would be sufficiently efficient for your taste? 30%? 60? 90? Can you explain why? It's just apples and pears on this level, the only reasonable comparison could come from a much broader view that you're explicitly not interested in. Anyway this discussion is going in circles. I'm not assuming bad faith on your side, but I don't think we'll come to an agreement either.