5 ms·

Well, pretty common, as weather systems are typically continental in scale. Even if you built enough wind turbines to satisfy 10000% of EU demand within the EU

Well, pretty common, as weather systems are typically continental in scale. Even if you built enough wind turbines to satisfy 10000% of EU demand within the EU (which is what you would need to have a shot at this kind of redundancy) the amount of huge HVDC interconnects you would need criss-crossing the continent make it completely impractical.

ben_w 4y ago
x100 over-capacity is at the level where an HVDC global power grid is easily cheaper. Why do you regard HVDC within Europe as impractical? Sure it would take a while, but there's already a grid. This is certainly achievable in my lifetime even without any interesting new tech like better superconductors or automation.
- JetSetWilly 4y ago
  Building an HVDC grid within Europe to allow local concentrations of renewable generation to be spread about more easily, and to further interlink the EU grid? That makes sense, sure. However for the "renewables can be base load" requirement it is completely impractical because of simple back of the envelope calculations. Suddenly you need multiple TWs of wind generation capability in every spot where it might be windy when calm elsewhere, and you need enough transmission to get TWs of power out from any random location within the EU. This is pipe dream territory.
  - ben_w 4y ago
    The need is 3m^2 cross section of conductor for the entire planet's current electricity usage, which at antipodal scale is 17 years of current global production of copper and aluminium. Production of aluminium is limited by electrical supply, and PV electricity is cheap enough to expand that aluminium supply. A 25% increase in global aluminium supply is significant, but not pipe-dream, and that percentage is sufficient for completing the task before the end of the century. What I don't know is how long such a cable would last, which matters for total lifetime cost. But construction cost at current prices is on the order of a few trillion, which sure, is loads, but that's for a genuinely global infrastructure project that essentially replaces the multi trillion dollar per year fossil electricity industry. Biggest problem is probably the geopolitics.
cycomanic 4y ago
Are you just making up numbers? Have you ever done any sailing? I can tell you that weather patterns on with no wind for extended periods of time even over the size of a country are not really happening. People have done studies and the amount of overprovisioning is typically on the order of 5x IIRC without storage. Moreover you need at least 2x overcapacity for nuclear as well.
- JetSetWilly 4y ago
  > I can tell you that weather patterns on with no wind for extended periods of time even over the size of a country are not really happening. That just isn't true - there's been plenty of times where eg the UK is generating wind power at just a few percent of total capacity because of low wind. And it just is not unusual for periods of calm in the UK to also be calm in neighbouring countries. Even at a continental level, and averaged out over months long periods, wind is pretty variable and unpredictable: https://theconversation.com/what-europes-exceptionally-low-winds-mean-for-the-future-energy-grid-170135 https://theconversation.com/what-europes-exceptionally-low-w... - if you look there we can see that wind power generation at a European level was down 32% on long term average over summer and autumn 2021.
  - ben_w 4y ago
    > https://theconversation.com/what-europes-exceptionally-low-winds-mean-for-the-future-energy-grid-170135 https://theconversation.com/what-europes-exceptionally-low-w... - if you look there we can see that wind power generation at a European level was down 32% on long term average over summer and autumn 2021. That's not what that article says, but even if it was it would imply a need of only x1.47 not x100: """For instance, UK-based power company SSE stated that its renewable assets produced 32% less power than expected.""" (SSE being initials for "Scottish and Southern Energy").
- ben_w 4y ago
  Thanks for the numbers! But do you have a source? x100 felt off, but I couldn't contradict it as I (still) don't know where to look for any references of any multiplier.

ben_w 4y ago

x100 over-capacity is at the level where an HVDC global power grid is easily cheaper. Why do you regard HVDC within Europe as impractical? Sure it would take a while, but there's already a grid. This is certainly achievable in my lifetime even without any interesting new tech like better superconductors or automation.

JetSetWilly 4y ago
Building an HVDC grid within Europe to allow local concentrations of renewable generation to be spread about more easily, and to further interlink the EU grid? That makes sense, sure. However for the "renewables can be base load" requirement it is completely impractical because of simple back of the envelope calculations. Suddenly you need multiple TWs of wind generation capability in every spot where it might be windy when calm elsewhere, and you need enough transmission to get TWs of power out from any random location within the EU. This is pipe dream territory.
- ben_w 4y ago
  The need is 3m^2 cross section of conductor for the entire planet's current electricity usage, which at antipodal scale is 17 years of current global production of copper and aluminium. Production of aluminium is limited by electrical supply, and PV electricity is cheap enough to expand that aluminium supply. A 25% increase in global aluminium supply is significant, but not pipe-dream, and that percentage is sufficient for completing the task before the end of the century. What I don't know is how long such a cable would last, which matters for total lifetime cost. But construction cost at current prices is on the order of a few trillion, which sure, is loads, but that's for a genuinely global infrastructure project that essentially replaces the multi trillion dollar per year fossil electricity industry. Biggest problem is probably the geopolitics.

cycomanic 4y ago

Are you just making up numbers? Have you ever done any sailing? I can tell you that weather patterns on with no wind for extended periods of time even over the size of a country are not really happening. People have done studies and the amount of overprovisioning is typically on the order of 5x IIRC without storage. Moreover you need at least 2x overcapacity for nuclear as well.

JetSetWilly 4y ago
> I can tell you that weather patterns on with no wind for extended periods of time even over the size of a country are not really happening. That just isn't true - there's been plenty of times where eg the UK is generating wind power at just a few percent of total capacity because of low wind. And it just is not unusual for periods of calm in the UK to also be calm in neighbouring countries. Even at a continental level, and averaged out over months long periods, wind is pretty variable and unpredictable: https://theconversation.com/what-europes-exceptionally-low-winds-mean-for-the-future-energy-grid-170135 https://theconversation.com/what-europes-exceptionally-low-w... - if you look there we can see that wind power generation at a European level was down 32% on long term average over summer and autumn 2021.
- ben_w 4y ago
  > https://theconversation.com/what-europes-exceptionally-low-winds-mean-for-the-future-energy-grid-170135 https://theconversation.com/what-europes-exceptionally-low-w... - if you look there we can see that wind power generation at a European level was down 32% on long term average over summer and autumn 2021. That's not what that article says, but even if it was it would imply a need of only x1.47 not x100: """For instance, UK-based power company SSE stated that its renewable assets produced 32% less power than expected.""" (SSE being initials for "Scottish and Southern Energy").
ben_w 4y ago
Thanks for the numbers! But do you have a source? x100 felt off, but I couldn't contradict it as I (still) don't know where to look for any references of any multiplier.