8 ms·

This LCA study shows wind, large hydro and 4Gen nuclear to be in the same range. With solar pv being higher. https://www.mdpi.com/1996-1073/11/12/3452/htm http

This LCA study shows wind, large hydro and 4Gen nuclear to be in the same range. With solar pv being higher. https://www.mdpi.com/1996-1073/11/12/3452/htm https://www.mdpi.com/1996-1073/11/12/3452/htm

nightski 8y ago
Still that is only greenhouse gasses and not full environmental impact. Renewables take up a lot of space.
- Tade0 8y ago
  Yes, but that space may well be someone's roof.
  - ThomPete 8y ago
    Not for anything substantial plus there are plenty of solar and (all wind) that doesn't sit on someone's roof.
    - TheOtherHobbes 8y ago
      Define substantial. Domestic PV installations reliably produce a significant percentage of domestic consumption - even in countries like Germany and the UK, which aren't known for bright sun. Countries that do have bright sun typically skip straight to passive solar water heating systems, which can do an excellent job of eliminating water heating costs.
- adrianN 8y ago
  It's not like the world is running out of space anytime soon.
  - tomp 8y ago
    But maybe we don’t want to pave the Earth with PV panels...
    - pfdietz 8y ago
      The world is bathed in 100,000 TW of sunlight. Current world primary energy consumption is 20 TW, 1/5000th of that amount. In contrast, 11% of the Earth's land area is under cultivation for crops. Add pastureland and that increases to 37%. Why the outrage over PV land use, when it will be just a pimple on agriculture's land use butt?
      - fisherjeff 8y ago
        Well, taking PV array efficiency and land vs. sea area into account, that’s probably closer to 0.5% of Earth’s land area that would have to be covered with panels. Obviously not a huge amount relative to agricultural land but we’re still probably talking about a butt pimple around the size of California.
        pfdietz 8y ago
        Primary energy use, though, is energy content of sources before they go through thermal cycles to get work. So one should also take into account the heat rejected in the latter. Nearly 80% of the energy content of gasoline, for example, goes out the tailpipe and radiator as heat. PV would deliver energy in high quality form, electrical power, not as heat. So less than 20 TW, probably much less, would be needed to be equivalent to today's energy usage (although precisely how much would depend on details.) Energy use will be increasing though, as the world gets wealthier. Still, this will also put pressure on agriculture to increase production, as demand for meat increases. Land constraints in the future will come from that, not from PV.
      - ThomPete 8y ago
        Because the energy density is extremely low compared to ex nuclear. And that it's not just about land use it's also about rare earth materials, the actual production of that many, the installation and maintanance plus no plans for decommision and it still needs ex coal to back it up because it's unrealiable.
  - majewsky 8y ago
    So they cut down the rainforest for fun? Didn't know that.
    - imtringued 8y ago
      Is this supposed to be some kind of joke? I can think of many reasons why the rainforest is cut down but lack of space for PV isn't one of them. Just think about it. Cutting down trees costs a lot of money in terms of acres. You need expensive machinery, trained workers and a lot of time. In other words people who cut down the rainforest do it with the intention to make a profit selling the wood they cut down. People who "care" about the land itself first burn down the trees because it is faster/cheaper and second because the ash acts as fertilizer in the short term. The rain forest is also rich in a fertile soil called humus which again acts as a fertilizer. But this layer of humus is quickly depleted because it is no longer protected by trees and simply gets washed away. The end result is infertile land and the farmers have to burn down the rainforest again. It's not like this is unexpected. The similar things happen on regular farms which is why we use artificial fertilizer, so in other words: people destroy the rainforest because they want to make a quick buck. If they really cared about the land they wouldn't abandon it as soon as it becomes unprofitable.
- imtringued 8y ago
  I don't think it makes sense to assume that there is an energy technology that doesn't produce environmental harm. Nuclear power plants increase the temperature of rivers and they are pretty good fish killing machines.
ThomPete 8y ago
Doesent take entire chain into account. Also keep in mind wind and solar needs backup powers thats often coal. Nuclear is by far the grenest.

nightski 8y ago

Still that is only greenhouse gasses and not full environmental impact. Renewables take up a lot of space.

Tade0 8y ago
Yes, but that space may well be someone's roof.
- ThomPete 8y ago
  Not for anything substantial plus there are plenty of solar and (all wind) that doesn't sit on someone's roof.
  - TheOtherHobbes 8y ago
    Define substantial. Domestic PV installations reliably produce a significant percentage of domestic consumption - even in countries like Germany and the UK, which aren't known for bright sun. Countries that do have bright sun typically skip straight to passive solar water heating systems, which can do an excellent job of eliminating water heating costs.
adrianN 8y ago
It's not like the world is running out of space anytime soon.
- tomp 8y ago
  But maybe we don’t want to pave the Earth with PV panels...
  - pfdietz 8y ago
    The world is bathed in 100,000 TW of sunlight. Current world primary energy consumption is 20 TW, 1/5000th of that amount. In contrast, 11% of the Earth's land area is under cultivation for crops. Add pastureland and that increases to 37%. Why the outrage over PV land use, when it will be just a pimple on agriculture's land use butt?
    - fisherjeff 8y ago
      Well, taking PV array efficiency and land vs. sea area into account, that’s probably closer to 0.5% of Earth’s land area that would have to be covered with panels. Obviously not a huge amount relative to agricultural land but we’re still probably talking about a butt pimple around the size of California.
      - pfdietz 8y ago
        Primary energy use, though, is energy content of sources before they go through thermal cycles to get work. So one should also take into account the heat rejected in the latter. Nearly 80% of the energy content of gasoline, for example, goes out the tailpipe and radiator as heat. PV would deliver energy in high quality form, electrical power, not as heat. So less than 20 TW, probably much less, would be needed to be equivalent to today's energy usage (although precisely how much would depend on details.) Energy use will be increasing though, as the world gets wealthier. Still, this will also put pressure on agriculture to increase production, as demand for meat increases. Land constraints in the future will come from that, not from PV.
    - ThomPete 8y ago
      Because the energy density is extremely low compared to ex nuclear. And that it's not just about land use it's also about rare earth materials, the actual production of that many, the installation and maintanance plus no plans for decommision and it still needs ex coal to back it up because it's unrealiable.
- majewsky 8y ago
  So they cut down the rainforest for fun? Didn't know that.
  - imtringued 8y ago
    Is this supposed to be some kind of joke? I can think of many reasons why the rainforest is cut down but lack of space for PV isn't one of them. Just think about it. Cutting down trees costs a lot of money in terms of acres. You need expensive machinery, trained workers and a lot of time. In other words people who cut down the rainforest do it with the intention to make a profit selling the wood they cut down. People who "care" about the land itself first burn down the trees because it is faster/cheaper and second because the ash acts as fertilizer in the short term. The rain forest is also rich in a fertile soil called humus which again acts as a fertilizer. But this layer of humus is quickly depleted because it is no longer protected by trees and simply gets washed away. The end result is infertile land and the farmers have to burn down the rainforest again. It's not like this is unexpected. The similar things happen on regular farms which is why we use artificial fertilizer, so in other words: people destroy the rainforest because they want to make a quick buck. If they really cared about the land they wouldn't abandon it as soon as it becomes unprofitable.
imtringued 8y ago
I don't think it makes sense to assume that there is an energy technology that doesn't produce environmental harm. Nuclear power plants increase the temperature of rivers and they are pretty good fish killing machines.

ThomPete 8y ago

Doesent take entire chain into account. Also keep in mind wind and solar needs backup powers thats often coal. Nuclear is by far the grenest.