4 ms·

Some like a transmission issue, not an electricity generation issue.

by standardUser 2y ago

autoexecbat 2y ago
Some transmission issues are solved by local generation
- deleted 2y ago
  [deleted]
Jensson 2y ago
How would transmission solve the massive electricity demand during cold winter nights? Even in more southern areas generation during winter is lower, then pay the massive loss of transmitting that so far north and it is no longer viable.
- kragen 2y ago
  hvdc transmission doesn't have massive losses from transmitting long distances, so you could literally transmit power from the tropics or even the other hemisphere. but overprovisioning solar locally is probably cheaper
  - wait_a_minute 2y ago
    Are there hvdc transmission lines already spanning those kinds of distances? How much raw material and upkeep does that require? If over-provisioning solar, how much more surface area would be needed to have the solar? Seems like the additional costs would pile up to get to current energy needs being met by just solar.
    - kragen 2y ago
      you'll probably be interested in reading https://en.wikipedia.org/wiki/High-voltage_direct_current https://en.wikipedia.org/wiki/High-voltage_direct_current. it says typical losses are 3.5% per 1000km, and typical voltages are 100–800 kilovolts, but china built a 12-gigawatt 1100-kilovolt link over 3300km in 02019 unfortunately i don't have a good handle on how efficient that link is. the numbers above suggest it would be about 89% efficient, but those are for lower-voltage systems in general you expect the resistive losses in the cables, at a given diameter and power, to scale with the inverse square of the voltage, so an 1100-kilovolt link should have 47% less resistive losses than an 800-kilovolt link at the same power level running over the same cables. however, corona-discharge losses increase at higher voltages rather than decreasing, and i don't know which one is dominant. so i don't know if that link is closer to 89% efficient or closer to 95% efficient the distance from the north or south pole to the equator is of course 10000 km, but people don't build very near the poles. for example, from svalbard to algiers is 4700 km. so, yeah, there are hvdc transmission lines already spanning those kinds of distances, but not quite that far yet transmission lines require utterly insignificant quantities of raw material, but where they cut through forested terrain, they do require upkeep. in the meeting of a tree and a megavolt, neither one comes out unscathed for some calculations on how much you need to over-provision solar, see my earlier comment at https://news.ycombinator.com/item?id=40724349 https://news.ycombinator.com/item?id=40724349 considering a counterfactual where somehow norway had to use solar. 6.1 average kilowatts per norwegian at a capacity factor of 6% works out to 102 kilowatts peak per norwegian. if you're using low-cost 16%-efficient solar panels (as i assumed you would in my cost estimate, even though mostly people spring for the more efficient 'mainstream' ones) that would require 635 kilowatts of sunlight per norwegian, which is 635 square meters per norwegian (we rate solar panels on the assumption that sunlight is 1000 watts per square meter). 635 square meters is 25 meters square, .000635 square kilometers per norwegian. multiplying that by 5.5 million norwegians gives you the truly immense area of 3500 square kilometers of solar panels but wait! that's not all! you can't just lay the panels out flat on the ground and expect them to get a 6% capacity factor. you have to angle them toward the equator and spread them out so they don't shade each other. oslo is at 60° north, so your panels need to be angled at 60° from the horizontal, toward the south. maybe a bit more if you want to increase power production in winter, say 69°. so you have to space them out by 1/cos 69° ≈ 2.8. so actually you need 9800 square kilometers for your €340 billion of solar panels. how much space will you have left? a lot, it turns out. norway is 385000 square kilometers, so this is still just 2.5% of the country so norway, despite being the #2 highest user of energy per capita in the world after canada, and having cities that are literally inside the arctic circle, could switch to all solar. it's totally feasible. fortunately they have plenty of hydropower and wind so they don't need to
Heston 2y ago
It's definitely a generation issue. When there's no sun(overcast, nighttime) there's no energy. This doesn't even factor in solars quick deterioration from peak performance and the cost of the panels and environment damage from producing them.
- wait_a_minute 2y ago
  Yeah, I think people looking at just the upfront cost are not really acknowledging or addressing that solar panel installations degrade faster than a nuclear reactor. They also take up more space and as you mentioned will likely end up causing more damage to produce at planetary scale. They are definitely great when coupled with batteries for many use cases including decentralizing aspects of the grid for residential and smaller scale usages, but the raw performance of nuclear is impressive and exciting. So little inputs needed for how much you get, and for how long too. There are old reactors still producing after over 50 years…that is mind-boggling. Who knows how far the tech can be pushed with modern advancements and less blockers on developing the technology further. It should be in the toolbox as part of a strategy for renewable energy needs on Earth and beyond.
  - kragen 2y ago
    nuclear energy is very exciting and absolutely crucial for space exploration, but not economically competitive with solar in the foreseeable future on earth's surface there are also solar panels still producing power after 50 years; they do degrade a little, especially in the first ten years, but the 20–30 year panel lifetimes you see published are more of a warranty and accounting issue than anything else. (of course some panels crack or yellow within a year or two) it's true that solar farms take up a lot of space, but even in high-density countries like japan there is room for them. singapore might have a problem tho
    - wait_a_minute 2y ago
      What would surface area needs be like for over-provisioning needs in the US? What if we want to scale energy production by 2x or 10x or 100x for advanced industrial and commercial usage needs in the future? I think then the solar panel approach becomes limited on earth. You’re right that the panels don’t degrade a ton. I read online that after 20-30 years they might drop 15% efficiency. For residential usage that might be okay, but it does mean needing upkeep and worrying about baseline potential dropping, which in some climates could be bad. I do think a combination of the technologies is best, since scaling up energy production will be simpler and easier and more resource-friendly with nuclear than with more solar. Moving up the Kardashev scale will require capturing all the energy that can be captured from all sources so why let any go to waste. :)
loeg 2y ago
In that transmission is very expensive and inefficient in ways that are challenging to improve because of physics? Transmission isn't getting a lot better very quickly, and certainly not by waving a magic wand.
- kragen 2y ago
  transmission is in fact getting a lot better very quickly, becoming much less inefficient, because people rose to the challenge; i took some notes about recent hvdc systems in https://news.ycombinator.com/item?id=40725189 https://news.ycombinator.com/item?id=40725189

Some like a transmission issue, not an electricity generation issue.

autoexecbat 2y ago

Some transmission issues are solved by local generation

deleted 2y ago
[deleted]

Jensson 2y ago

How would transmission solve the massive electricity demand during cold winter nights? Even in more southern areas generation during winter is lower, then pay the massive loss of transmitting that so far north and it is no longer viable.

kragen 2y ago
hvdc transmission doesn't have massive losses from transmitting long distances, so you could literally transmit power from the tropics or even the other hemisphere. but overprovisioning solar locally is probably cheaper
- wait_a_minute 2y ago
  Are there hvdc transmission lines already spanning those kinds of distances? How much raw material and upkeep does that require? If over-provisioning solar, how much more surface area would be needed to have the solar? Seems like the additional costs would pile up to get to current energy needs being met by just solar.
  - kragen 2y ago
    you'll probably be interested in reading https://en.wikipedia.org/wiki/High-voltage_direct_current https://en.wikipedia.org/wiki/High-voltage_direct_current. it says typical losses are 3.5% per 1000km, and typical voltages are 100–800 kilovolts, but china built a 12-gigawatt 1100-kilovolt link over 3300km in 02019 unfortunately i don't have a good handle on how efficient that link is. the numbers above suggest it would be about 89% efficient, but those are for lower-voltage systems in general you expect the resistive losses in the cables, at a given diameter and power, to scale with the inverse square of the voltage, so an 1100-kilovolt link should have 47% less resistive losses than an 800-kilovolt link at the same power level running over the same cables. however, corona-discharge losses increase at higher voltages rather than decreasing, and i don't know which one is dominant. so i don't know if that link is closer to 89% efficient or closer to 95% efficient the distance from the north or south pole to the equator is of course 10000 km, but people don't build very near the poles. for example, from svalbard to algiers is 4700 km. so, yeah, there are hvdc transmission lines already spanning those kinds of distances, but not quite that far yet transmission lines require utterly insignificant quantities of raw material, but where they cut through forested terrain, they do require upkeep. in the meeting of a tree and a megavolt, neither one comes out unscathed for some calculations on how much you need to over-provision solar, see my earlier comment at https://news.ycombinator.com/item?id=40724349 https://news.ycombinator.com/item?id=40724349 considering a counterfactual where somehow norway had to use solar. 6.1 average kilowatts per norwegian at a capacity factor of 6% works out to 102 kilowatts peak per norwegian. if you're using low-cost 16%-efficient solar panels (as i assumed you would in my cost estimate, even though mostly people spring for the more efficient 'mainstream' ones) that would require 635 kilowatts of sunlight per norwegian, which is 635 square meters per norwegian (we rate solar panels on the assumption that sunlight is 1000 watts per square meter). 635 square meters is 25 meters square, .000635 square kilometers per norwegian. multiplying that by 5.5 million norwegians gives you the truly immense area of 3500 square kilometers of solar panels but wait! that's not all! you can't just lay the panels out flat on the ground and expect them to get a 6% capacity factor. you have to angle them toward the equator and spread them out so they don't shade each other. oslo is at 60° north, so your panels need to be angled at 60° from the horizontal, toward the south. maybe a bit more if you want to increase power production in winter, say 69°. so you have to space them out by 1/cos 69° ≈ 2.8. so actually you need 9800 square kilometers for your €340 billion of solar panels. how much space will you have left? a lot, it turns out. norway is 385000 square kilometers, so this is still just 2.5% of the country so norway, despite being the #2 highest user of energy per capita in the world after canada, and having cities that are literally inside the arctic circle, could switch to all solar. it's totally feasible. fortunately they have plenty of hydropower and wind so they don't need to

Heston 2y ago

It's definitely a generation issue. When there's no sun(overcast, nighttime) there's no energy. This doesn't even factor in solars quick deterioration from peak performance and the cost of the panels and environment damage from producing them.

wait_a_minute 2y ago
Yeah, I think people looking at just the upfront cost are not really acknowledging or addressing that solar panel installations degrade faster than a nuclear reactor. They also take up more space and as you mentioned will likely end up causing more damage to produce at planetary scale. They are definitely great when coupled with batteries for many use cases including decentralizing aspects of the grid for residential and smaller scale usages, but the raw performance of nuclear is impressive and exciting. So little inputs needed for how much you get, and for how long too. There are old reactors still producing after over 50 years…that is mind-boggling. Who knows how far the tech can be pushed with modern advancements and less blockers on developing the technology further. It should be in the toolbox as part of a strategy for renewable energy needs on Earth and beyond.
- kragen 2y ago
  nuclear energy is very exciting and absolutely crucial for space exploration, but not economically competitive with solar in the foreseeable future on earth's surface there are also solar panels still producing power after 50 years; they do degrade a little, especially in the first ten years, but the 20–30 year panel lifetimes you see published are more of a warranty and accounting issue than anything else. (of course some panels crack or yellow within a year or two) it's true that solar farms take up a lot of space, but even in high-density countries like japan there is room for them. singapore might have a problem tho
  - wait_a_minute 2y ago
    What would surface area needs be like for over-provisioning needs in the US? What if we want to scale energy production by 2x or 10x or 100x for advanced industrial and commercial usage needs in the future? I think then the solar panel approach becomes limited on earth. You’re right that the panels don’t degrade a ton. I read online that after 20-30 years they might drop 15% efficiency. For residential usage that might be okay, but it does mean needing upkeep and worrying about baseline potential dropping, which in some climates could be bad. I do think a combination of the technologies is best, since scaling up energy production will be simpler and easier and more resource-friendly with nuclear than with more solar. Moving up the Kardashev scale will require capturing all the energy that can be captured from all sources so why let any go to waste. :)

loeg 2y ago

In that transmission is very expensive and inefficient in ways that are challenging to improve because of physics? Transmission isn't getting a lot better very quickly, and certainly not by waving a magic wand.

kragen 2y ago
transmission is in fact getting a lot better very quickly, becoming much less inefficient, because people rose to the challenge; i took some notes about recent hvdc systems in https://news.ycombinator.com/item?id=40725189 https://news.ycombinator.com/item?id=40725189