5 ms·

> In this context, solar and wind are atrocious and a total disaster because they have massive land-use requirements. No, they don't. There is a lot of empty

by elihu 6y ago

> In this context, solar and wind are atrocious and a total disaster because they have massive land-use requirements. No, they don't. There is a lot of empty land in the world that isn't useful for people to live in or to grow crops due to lack of rainfall, which also makes those sites more valuable for solar energy. We'd consider a utility-scale solar array that's a couple square miles to be absolutely huge, but plotted on a map of, say, the United States it would be a barely visible dot in a massive sea of land-that-isn't-devoted-to-solar-power. The Earth is very big, and when you get outside the areas where people congregate there's a lot of wide open spaces. This says that US electricity consumption was 3.9 trillion killowatt-hours in 2019: https://www.eia.gov/energyexplained/electricity/use-of-electricity.php https://www.eia.gov/energyexplained/electricity/use-of-elect... 39 quadrillion watt hours divided by (36524) gives us average power consumption in watts. Let's say a pretty good solar panel gets 100 watts per square meter, then reduce that to 30 to account for night-time. If we divide average power consumption by 30 watts per meter and divide by 1,000,000 to convert to square kilometers, we get: Prelude> (((3.9 1000 * 1000 * 1000 * 1000 * 1000) / (36524)) / 30) / (1000 1000) 14840.182648401827 So, about 15,000 square kilometers of solar panels would satisfy current US electrical needs. Let's double that to be conservative, that's 30,000 square kilometers. Sounds like a lot, right? That's a rectangle 100 km by 300 km. It's slightly more than 10% of the land area of Nevada. Definitely big, but attainable. Compared to the land we use for farming, it's barely anything (and it can be done in places that we don't farm). And in practice it would be spread out, not just in one place. And it also assumes we get 100% of our power from solar, which we wouldn't.

macspoofing 6y ago
>There is a lot of empty land in the world that isn't useful for people to live in or to grow crops due to lack of rainfall, which also makes those sites more valuable for solar energy. There is no such thing as 'empty land'. Every square meter of Earth is part of some ecosystem that is under stress due to human activity. Solar and wind compound this problem. >then reduce that to 30 to account for night-time How about reduce that to 0 for night-time? I have yet to see a solar panel that works at night, or works well in cloud weather, or when covered by a layer of snow. >Sounds like a lot, right? That's a rectangle 100 km by 300 km. You missed some detail of land-use requirements in calculations. Like accounting for the battery technology that doesn't exist in order to bridge the intermittency of solar and wind. Also, even if this mythical battery technology existed, you would need to over-build wind and solar because after all, when the sun is shining you need to collect enough energy for right now + enough energy to save for later. Given that estimates say that we would need a minimum of few day (but more likely few weeks) of stored energy, for each day of power you generate, you need to over-generate a few days (or weeks) extra to store for later. Also, the population is growing. Our per-captia energy use is growing. But let's set that aside. That is a lot of land. How can you say it's not!!!?? Every single one of those panels will be land-filled and replaced continually ... forever. So you have 100km x 300km (+ whatever materials you need to support and maintain those panels) of shit going to landfills that then you will need to subsequently dig up again to replace ... forever. And that's just one country. Our ecosystem is already stressed!
- stopping 6y ago
  >How about reduce that to 0 for night-time? No, GP is averaging out across the whole day. If you get 100W during daylight and 0W during night, you can average to 50W for an entire 24-hour period. GP took 30W as a conservative estimate, which is entirely reasonable.
  - macspoofing 6y ago
    Thanks for clarification. But don't you find it misleading to amortize panel power generation across day and night? It makes it seem like you just need more panels to cover power demand in the evening and night .. when in reality, no amount of panels will ever work.
    - jlevers 6y ago
      I think that if you consider storage, then you can in fact amortize panel power generation across day and night, because you need more panels during the day to create the extra power that will be used at night (when none of the panels are actively generating power).
      - macspoofing 6y ago
        Then you have to over-build your infrastructure, not just for daily intermittency but also seasonal intermittency. So you have to add that to your calculation. But this point is moot anyway, because there is no battery technology that is capable of that much storage.
  - EricE 6y ago
    Where are you getting sufficient batteries in sufficient quantities to store that theoretical 50% overnight? And on top of that were are you getting the additional batteries to provide extra capacities for when the sun is shining at less than 100% of optimal? And then where are you getting all the materials for those batteries? And what are you doing with all the waste from those batteries once they end their serviceable lifespan? If you seriously are concerned about the latent costs with nuclear power plants then you should do more than gloss over the storage issues with solar. And many of your concerns about nuclear fall apart if you don't assume we would continue to build reactors with the issues you point out. There are new designs like micro molten salt reactors that address in pretty signifiant ways the concerns you note. A lot fewer construction materials, greatly simplified designs and designs that don't rely on active cooling to prevent a meltdown. Designs that if the reactor systems are interrupted, the reactors coast to a shutdown naturally. It's not science fiction - its proven technology we've had since the 50's that was refined in the 70's but squashed because of politics and fear mongering. Maybe after China starts eating our lunch we'll take it seriously? Ha - probably not even then, unfortunately.
ekianjo 6y ago
> also makes those sites more valuable for solar energy. Unfortunately, you don't need the energy where people do not live, and transporting energy has a efficiency cost as well. In other words, it's massively more efficient to produce energy where you use it.
EricE 6y ago
>No, they don't. There is a lot of empty land in the world that isn't useful for people to live in or to grow crops due to lack of rainfall, which also makes those sites more valuable for solar energy. Yes, I grew up near a lot of that land. Unfortunately that land is also far, far away from most of the population in the US and thus where energy is needed. You do realize transmission loss is a thing, right? And then what do you do when the sun isn't shining? We still consume power at night. If this was such a trivial problem we wouldn't still be talking about it, no?

by elihu 6y ago

macspoofing 6y ago

>There is a lot of empty land in the world that isn't useful for people to live in or to grow crops due to lack of rainfall, which also makes those sites more valuable for solar energy. There is no such thing as 'empty land'. Every square meter of Earth is part of some ecosystem that is under stress due to human activity. Solar and wind compound this problem. >then reduce that to 30 to account for night-time How about reduce that to 0 for night-time? I have yet to see a solar panel that works at night, or works well in cloud weather, or when covered by a layer of snow. >Sounds like a lot, right? That's a rectangle 100 km by 300 km. You missed some detail of land-use requirements in calculations. Like accounting for the battery technology that doesn't exist in order to bridge the intermittency of solar and wind. Also, even if this mythical battery technology existed, you would need to over-build wind and solar because after all, when the sun is shining you need to collect enough energy for right now + enough energy to save for later. Given that estimates say that we would need a minimum of few day (but more likely few weeks) of stored energy, for each day of power you generate, you need to over-generate a few days (or weeks) extra to store for later. Also, the population is growing. Our per-captia energy use is growing. But let's set that aside. That is a lot of land. How can you say it's not!!!?? Every single one of those panels will be land-filled and replaced continually ... forever. So you have 100km x 300km (+ whatever materials you need to support and maintain those panels) of shit going to landfills that then you will need to subsequently dig up again to replace ... forever. And that's just one country. Our ecosystem is already stressed!

stopping 6y ago
>How about reduce that to 0 for night-time? No, GP is averaging out across the whole day. If you get 100W during daylight and 0W during night, you can average to 50W for an entire 24-hour period. GP took 30W as a conservative estimate, which is entirely reasonable.
- macspoofing 6y ago
  Thanks for clarification. But don't you find it misleading to amortize panel power generation across day and night? It makes it seem like you just need more panels to cover power demand in the evening and night .. when in reality, no amount of panels will ever work.
  - jlevers 6y ago
    I think that if you consider storage, then you can in fact amortize panel power generation across day and night, because you need more panels during the day to create the extra power that will be used at night (when none of the panels are actively generating power).
    - macspoofing 6y ago
      Then you have to over-build your infrastructure, not just for daily intermittency but also seasonal intermittency. So you have to add that to your calculation. But this point is moot anyway, because there is no battery technology that is capable of that much storage.
- EricE 6y ago
  Where are you getting sufficient batteries in sufficient quantities to store that theoretical 50% overnight? And on top of that were are you getting the additional batteries to provide extra capacities for when the sun is shining at less than 100% of optimal? And then where are you getting all the materials for those batteries? And what are you doing with all the waste from those batteries once they end their serviceable lifespan? If you seriously are concerned about the latent costs with nuclear power plants then you should do more than gloss over the storage issues with solar. And many of your concerns about nuclear fall apart if you don't assume we would continue to build reactors with the issues you point out. There are new designs like micro molten salt reactors that address in pretty signifiant ways the concerns you note. A lot fewer construction materials, greatly simplified designs and designs that don't rely on active cooling to prevent a meltdown. Designs that if the reactor systems are interrupted, the reactors coast to a shutdown naturally. It's not science fiction - its proven technology we've had since the 50's that was refined in the 70's but squashed because of politics and fear mongering. Maybe after China starts eating our lunch we'll take it seriously? Ha - probably not even then, unfortunately.

ekianjo 6y ago

> also makes those sites more valuable for solar energy. Unfortunately, you don't need the energy where people do not live, and transporting energy has a efficiency cost as well. In other words, it's massively more efficient to produce energy where you use it.

EricE 6y ago

>No, they don't. There is a lot of empty land in the world that isn't useful for people to live in or to grow crops due to lack of rainfall, which also makes those sites more valuable for solar energy. Yes, I grew up near a lot of that land. Unfortunately that land is also far, far away from most of the population in the US and thus where energy is needed. You do realize transmission loss is a thing, right? And then what do you do when the sun isn't shining? We still consume power at night. If this was such a trivial problem we wouldn't still be talking about it, no?