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>> Can the world just run on renewables like Greenpeace is claiming? > The main obstacle to overcome is to decrease the consumption of energy If we can’t prod

>> Can the world just run on renewables like Greenpeace is claiming? > The main obstacle to overcome is to decrease the consumption of energy If we can’t produce enough power using renewables to meet current demand you cannot run the world on renewables. So “no”.

pfdietz 4y ago
We obviously could supply much more than current demand with renewables. After all, the world is constantly being hit by 100,000 TW of sunlight, and total world primary energy demand is 18 TW. If you are saying the currently installed renewables cannot meet current demand, why do you think additional capacity cannot be installed?
- kcplate 4y ago
  The commenter suggested that the problem with renewables is convincing people to consume less. That is not a direct replacement. Can capacity be installed? Sure. Do we have the resources to use renewable energy immediately available to meet our current demand? No, it has to be mined, manufactured, and installed. Can we do that in a way that is economically feasible is the real question.
  - pfdietz 4y ago
    Of course if you look at what's immediately available, it doesn't do. How could it possibly? No one has wind and solar fields sitting around idle, just waiting to be turned on. New capacity would have to be built. That takes time (but much less time than nuclear). It takes resources, but the resources required are small compared to what industrial society as a whole consumes. And if you look at raw mass of material extracted from the ground, fossil fuels are the vast majority of mass extracted (ignoring ground water). In comparison, the metals and other materials needed for renewable sources are much less (orders of magnitude less) for a given amount of energy production.
    - forty 4y ago
      Yeah I'm not sure why it was concluded from my comment that I was suggesting to keep the current renewable energy production at current capacity. We need to lower consumption and build more clean (or cleaner, nothing is really clean except what's not produced) energy production.
      - pfdietz 4y ago
        It may be a good idea to lower current consumption, but it's by no means necessary. The available renewable resource is very large. Total world rate of primary energy consumption is around 18 TW (which might correspond to 10 TW of work); the world is constantly being hit by 100,000 TW of sunlight.
        forty 4y ago
        You are probably right in theory, but I think all serious plans I have seen to switch to full renewable energy involved some reduction of the consumption. It's not that it's strictly necessary, but it's probably more practical in the short term at least.
        pfdietz 4y ago
        I think all plans globally involve serious increases in consumption. Otherwise, one is assuming most of the world's population stays in a state of energy poverty.
      - kcplate 4y ago
        I didn’t conclude that you were suggesting that we could—-quite the opposite, I posted both the original comment and yours to make the distinction. Your comment was responding to the notion that the world can run on renewables. You didn’t make the claim that it could, you made the claim that we would need to decrease consumption so it could. So the answer is “no” at current consumption and current renewable capacity. Further consumption will only increase, so to get to a 100% renewable place, we need to account for capacity increase and build that into the equation. We cannot make moving to renewables dependent of something that will not happen.

pfdietz 4y ago

We obviously could supply much more than current demand with renewables. After all, the world is constantly being hit by 100,000 TW of sunlight, and total world primary energy demand is 18 TW. If you are saying the currently installed renewables cannot meet current demand, why do you think additional capacity cannot be installed?

kcplate 4y ago
The commenter suggested that the problem with renewables is convincing people to consume less. That is not a direct replacement. Can capacity be installed? Sure. Do we have the resources to use renewable energy immediately available to meet our current demand? No, it has to be mined, manufactured, and installed. Can we do that in a way that is economically feasible is the real question.
- pfdietz 4y ago
  Of course if you look at what's immediately available, it doesn't do. How could it possibly? No one has wind and solar fields sitting around idle, just waiting to be turned on. New capacity would have to be built. That takes time (but much less time than nuclear). It takes resources, but the resources required are small compared to what industrial society as a whole consumes. And if you look at raw mass of material extracted from the ground, fossil fuels are the vast majority of mass extracted (ignoring ground water). In comparison, the metals and other materials needed for renewable sources are much less (orders of magnitude less) for a given amount of energy production.
  - forty 4y ago
    Yeah I'm not sure why it was concluded from my comment that I was suggesting to keep the current renewable energy production at current capacity. We need to lower consumption and build more clean (or cleaner, nothing is really clean except what's not produced) energy production.
    - pfdietz 4y ago
      It may be a good idea to lower current consumption, but it's by no means necessary. The available renewable resource is very large. Total world rate of primary energy consumption is around 18 TW (which might correspond to 10 TW of work); the world is constantly being hit by 100,000 TW of sunlight.
      - forty 4y ago
        You are probably right in theory, but I think all serious plans I have seen to switch to full renewable energy involved some reduction of the consumption. It's not that it's strictly necessary, but it's probably more practical in the short term at least.
        pfdietz 4y ago
        I think all plans globally involve serious increases in consumption. Otherwise, one is assuming most of the world's population stays in a state of energy poverty.
    - kcplate 4y ago
      I didn’t conclude that you were suggesting that we could—-quite the opposite, I posted both the original comment and yours to make the distinction. Your comment was responding to the notion that the world can run on renewables. You didn’t make the claim that it could, you made the claim that we would need to decrease consumption so it could. So the answer is “no” at current consumption and current renewable capacity. Further consumption will only increase, so to get to a 100% renewable place, we need to account for capacity increase and build that into the equation. We cannot make moving to renewables dependent of something that will not happen.