9 ms·

Can solar scale enough to cover our needs or would we run into space issues? (And keep in mind most countries don't have the USA's space availability)

by fifnir 7y ago

Can solar scale enough to cover our needs or would we run into space issues? (And keep in mind most countries don't have the USA's space availability) What would be the environmental impact of covering as much land as we need to cover with photovoltaics or wind turbines?

arghwhat 7y ago
The benefit of solar is that you can install it on homes and make them self-sufficient (using battery storage at night), or at least vastly reduce the load on the grid. It does not require "new" space, as it simply takes over your roof.
- fifnir 7y ago
  That would probably work in american suburbia but would it even make a dent in the power consumption of densely inhabited cities?
edhelas 7y ago
http://www.assemblee-nationale.fr/15/pdf/rap-enq/r2195-t1.pdf http://www.assemblee-nationale.fr/15/pdf/rap-enq/r2195-t1.pd... "Lors de leur audition précitée, les représentants du BRGM ont indiqué que pour remplacer un réacteur nucléaire de 1 GW fonctionnant avec un facteur de charge de 75 %, il faudrait recouvrir 5200hectares de panneaux photovoltaïques, soit la moitié de la surface de Paris." Replacing a 1GW nuclear reactor (a power plan can have 2, 3 or 4) with a capacity factor of 75% will need 5200h of solar panels, half of Paris surface. This doesn't also solve the transport and storage issues to handle the intermittence. After that you simply have to do the maths. Knowing that solar panels are loosing efficiency over time and needs to be replaced after 20 years. Nuclear power plants are currently holding after 70 years.
- iso1631 7y ago
  5200h is 52km2 France is 551,695 km2 So 1/10,000th of france would be needed for 1GW A 1GW reactor produces 9 billion kwh a year France's entire electric requirement is 450 billion, so needs about 50GW, or 0.5% of France's surface area. Based on those figures, space isn't a problem.
  - wnkrshm 7y ago
    If you draw a 50x50km square on a map of France, you'll quickly realize that's an area the size of Luxembourg - not exactly negligible.
    - kragen 7y ago
      A 50×50 km square would be 2500 km². We're talking about 52 km², which is a 7.2 km × 7.2 km square. Shitty dimensional analysis strikes again!
      - wnkrshm 7y ago
        > A 50×50 km square would be 2500 km². We're talking about 52 km², which is a 7.2 km × 7.2 km square. Shitty dimensional analysis strikes again! According to the parent poster, those 52 km² are needed for 1GW. France needs around 50GW, 50 times more power and area, ergo 2500 km².
        kragen 7y ago
        Oh, I see. Thank you for clarifying.
        fifnir 7y ago
        The US would need about 50x500km !
    - deleted 7y ago
      [deleted]
    - iso1631 7y ago
      Pretty much. How much is used by vinyards? Or farms? It's the yellow dots here https://imgur.com/418BI6Q https://imgur.com/418BI6Q France has about 1 million km of roads [1], lets assume at least 2m wide. That's 2,000 sq km. How many of these roads can you see on this picture https://imgur.com/FCyt4O6 https://imgur.com/FCyt4O6 [1] https://en.wikipedia.org/wiki/List_of_countries_by_road_network_size https://en.wikipedia.org/wiki/List_of_countries_by_road_netw...
koheripbal 7y ago
Generation isn't the bottleneck - it's the storage. Solar produces dramatically less power in the winter, and having season long storage is not practical. As an example, the largest plant in Arizona produces only 10% in January compared to June.
- skitout 7y ago
  1) That is why you should rely on different (renewable) complementary energy : solar, onshore wind, offshore wind, biomass, hydro 2) You don't really NEED Season long storage, but Season long thermal storage would do the job
  - koheripbal 7y ago
    1. This doesn't address my point at all. 2. Of course you do. Power needs to be 99.95% reliable. We cannot have entire winters without power just because the sun wasn't out enough in one particular June. ..."thermal storage" is incredibly inefficient and entirely theoretical.
    - kragen 7y ago
      No, seasonal thermal energy stores are a well-known technology with many large-scale deployments: https://en.wikipedia.org/wiki/Seasonal_thermal_store https://en.wikipedia.org/wiki/Seasonal_thermal_store But they are only applicable in some cases. Utility-scale seasonal electrical energy storage is orders of magnitude from practicality. You don't need it, though. Most populated places can easily install enough solar panels to provide their winter energy demands, providing a great surplus of energy during the summer.
    - tonyedgecombe 7y ago
      Perhaps continuous power is a luxury we can’t afford.
      - Gibbon1 7y ago
        My thought is we could use combined cycle nature gas power plants to back stop renewable's. So lack of storage isn't the show stopper people seem to think it is.
wnkrshm 7y ago
Many are only looking at solar panels in term of greenhouse gas emission in the production chain, while any kind of semiconductor processing will have a lot of chemical waste occuring. Edit: Also, recycling solar panels isn't sraightforward at all because of heavy metals (e.g. Cadmium) being used as dopants.
- kragen 7y ago
  Semiconductor process waste is a real problem (I used to work in an office where the old Fairchild Semiconductor plant had been, which I was told was the first Superfund site, though it wasn't) but it's actually a very manageable problem. It isn't inherent to the process in the way that CO₂ emission is inherent to burning coal, smelting steel, or making concrete, and it's orders of magnitude better than it used to be.
- kragen 7y ago
  No, most solar panels do not contain cadmium, and cadmium is not used as a dopant in any kind of semiconductor. Cadmium telluride is a semiconductor, and there are some thin-film solar panels that use it, but the market is dominated by silicon solar panels, which do not contain any cadmium. (CdTe is the most popular thin-film type, though.) Recycling CdTe is enormously easier than mining cadmium and tellurium from ore, so it won't be a problem. If I were doing it, I'd be more worried about the tellurium than the cadmium — that shit stinks in a way that gives new layers of meaning to the word "stench". Finally, "cadmium" is not a brand name; it is a chemical element and thus does not need to be capitalized. This isn't German. > Excretion is mainly renal although small amounts of tellurium are exhaled as dimethyl telluride which has a distinctive garlic odour which may persist for many days; Reisert (1884) reported garlic breath odour for 237 days following ingestion of 15 mg tellurium oxide. In short, you have managed to pack so many errors into under 20 words that it required an entire paragraph to explain most of them. Your epistemology is bad and you should feel bad.
  - wnkrshm 7y ago
    Thank you for clearing that up then. For the record, I do feel bad.
kragen 7y ago
The environmental impact of covering enough land to fulfill world marketed energy demand would probably be insignificant, especially compared to agriculture. The sun on 0.1% of the world's surface would provide all of world marketed energy demand. There are some possible nuances, though: 1. We do need to be careful about the environmental impact of the manufacturing. Current semiconductor manufacturing is not a major polluter, but semiconductor manufacturing has been a major polluter in the past before emissions controls were imposed, and we're talking about scaling up semiconductor fabrication by about three orders of magnitude. 2. Shading a significant proportion of the Atacama, the Sahara, and the Gobi will surely produce local environmental changes. Perhaps it will give rise to new oases, as shipwrecks sometimes become artificial reefs. But it's hard to predict things like this. 3. It seems very unlikely that energy demand will remain static in the face of such a dramatic expansion of energy supply and consequent lowering of costs, so construction probably will not stop just because current world marketed energy demand is met. In the 2040s we will surely be complaining about the percentage of the Pacific that is covered in nasty solar barges.

by fifnir 7y ago

arghwhat 7y ago

The benefit of solar is that you can install it on homes and make them self-sufficient (using battery storage at night), or at least vastly reduce the load on the grid. It does not require "new" space, as it simply takes over your roof.

fifnir 7y ago
That would probably work in american suburbia but would it even make a dent in the power consumption of densely inhabited cities?

edhelas 7y ago

http://www.assemblee-nationale.fr/15/pdf/rap-enq/r2195-t1.pdf http://www.assemblee-nationale.fr/15/pdf/rap-enq/r2195-t1.pd... "Lors de leur audition précitée, les représentants du BRGM ont indiqué que pour remplacer un réacteur nucléaire de 1 GW fonctionnant avec un facteur de charge de 75 %, il faudrait recouvrir 5200hectares de panneaux photovoltaïques, soit la moitié de la surface de Paris." Replacing a 1GW nuclear reactor (a power plan can have 2, 3 or 4) with a capacity factor of 75% will need 5200h of solar panels, half of Paris surface. This doesn't also solve the transport and storage issues to handle the intermittence. After that you simply have to do the maths. Knowing that solar panels are loosing efficiency over time and needs to be replaced after 20 years. Nuclear power plants are currently holding after 70 years.

iso1631 7y ago
5200h is 52km2 France is 551,695 km2 So 1/10,000th of france would be needed for 1GW A 1GW reactor produces 9 billion kwh a year France's entire electric requirement is 450 billion, so needs about 50GW, or 0.5% of France's surface area. Based on those figures, space isn't a problem.
- wnkrshm 7y ago
  If you draw a 50x50km square on a map of France, you'll quickly realize that's an area the size of Luxembourg - not exactly negligible.
  - kragen 7y ago
    A 50×50 km square would be 2500 km². We're talking about 52 km², which is a 7.2 km × 7.2 km square. Shitty dimensional analysis strikes again!
    - wnkrshm 7y ago
      > A 50×50 km square would be 2500 km². We're talking about 52 km², which is a 7.2 km × 7.2 km square. Shitty dimensional analysis strikes again! According to the parent poster, those 52 km² are needed for 1GW. France needs around 50GW, 50 times more power and area, ergo 2500 km².
      - kragen 7y ago
        Oh, I see. Thank you for clarifying.
        fifnir 7y ago
        The US would need about 50x500km !
  - deleted 7y ago
    [deleted]
  - iso1631 7y ago
    Pretty much. How much is used by vinyards? Or farms? It's the yellow dots here https://imgur.com/418BI6Q https://imgur.com/418BI6Q France has about 1 million km of roads [1], lets assume at least 2m wide. That's 2,000 sq km. How many of these roads can you see on this picture https://imgur.com/FCyt4O6 https://imgur.com/FCyt4O6 [1] https://en.wikipedia.org/wiki/List_of_countries_by_road_network_size https://en.wikipedia.org/wiki/List_of_countries_by_road_netw...

koheripbal 7y ago

Generation isn't the bottleneck - it's the storage. Solar produces dramatically less power in the winter, and having season long storage is not practical. As an example, the largest plant in Arizona produces only 10% in January compared to June.

skitout 7y ago
1) That is why you should rely on different (renewable) complementary energy : solar, onshore wind, offshore wind, biomass, hydro 2) You don't really NEED Season long storage, but Season long thermal storage would do the job
- koheripbal 7y ago
  1. This doesn't address my point at all. 2. Of course you do. Power needs to be 99.95% reliable. We cannot have entire winters without power just because the sun wasn't out enough in one particular June. ..."thermal storage" is incredibly inefficient and entirely theoretical.
  - kragen 7y ago
    No, seasonal thermal energy stores are a well-known technology with many large-scale deployments: https://en.wikipedia.org/wiki/Seasonal_thermal_store https://en.wikipedia.org/wiki/Seasonal_thermal_store But they are only applicable in some cases. Utility-scale seasonal electrical energy storage is orders of magnitude from practicality. You don't need it, though. Most populated places can easily install enough solar panels to provide their winter energy demands, providing a great surplus of energy during the summer.
  - tonyedgecombe 7y ago
    Perhaps continuous power is a luxury we can’t afford.
    - Gibbon1 7y ago
      My thought is we could use combined cycle nature gas power plants to back stop renewable's. So lack of storage isn't the show stopper people seem to think it is.

wnkrshm 7y ago

Many are only looking at solar panels in term of greenhouse gas emission in the production chain, while any kind of semiconductor processing will have a lot of chemical waste occuring. Edit: Also, recycling solar panels isn't sraightforward at all because of heavy metals (e.g. Cadmium) being used as dopants.

kragen 7y ago
Semiconductor process waste is a real problem (I used to work in an office where the old Fairchild Semiconductor plant had been, which I was told was the first Superfund site, though it wasn't) but it's actually a very manageable problem. It isn't inherent to the process in the way that CO₂ emission is inherent to burning coal, smelting steel, or making concrete, and it's orders of magnitude better than it used to be.
kragen 7y ago
No, most solar panels do not contain cadmium, and cadmium is not used as a dopant in any kind of semiconductor. Cadmium telluride is a semiconductor, and there are some thin-film solar panels that use it, but the market is dominated by silicon solar panels, which do not contain any cadmium. (CdTe is the most popular thin-film type, though.) Recycling CdTe is enormously easier than mining cadmium and tellurium from ore, so it won't be a problem. If I were doing it, I'd be more worried about the tellurium than the cadmium — that shit stinks in a way that gives new layers of meaning to the word "stench". Finally, "cadmium" is not a brand name; it is a chemical element and thus does not need to be capitalized. This isn't German. > Excretion is mainly renal although small amounts of tellurium are exhaled as dimethyl telluride which has a distinctive garlic odour which may persist for many days; Reisert (1884) reported garlic breath odour for 237 days following ingestion of 15 mg tellurium oxide. In short, you have managed to pack so many errors into under 20 words that it required an entire paragraph to explain most of them. Your epistemology is bad and you should feel bad.
- wnkrshm 7y ago
  Thank you for clearing that up then. For the record, I do feel bad.

kragen 7y ago

The environmental impact of covering enough land to fulfill world marketed energy demand would probably be insignificant, especially compared to agriculture. The sun on 0.1% of the world's surface would provide all of world marketed energy demand. There are some possible nuances, though: 1. We do need to be careful about the environmental impact of the manufacturing. Current semiconductor manufacturing is not a major polluter, but semiconductor manufacturing has been a major polluter in the past before emissions controls were imposed, and we're talking about scaling up semiconductor fabrication by about three orders of magnitude. 2. Shading a significant proportion of the Atacama, the Sahara, and the Gobi will surely produce local environmental changes. Perhaps it will give rise to new oases, as shipwrecks sometimes become artificial reefs. But it's hard to predict things like this. 3. It seems very unlikely that energy demand will remain static in the face of such a dramatic expansion of energy supply and consequent lowering of costs, so construction probably will not stop just because current world marketed energy demand is met. In the 2040s we will surely be complaining about the percentage of the Pacific that is covered in nasty solar barges.