6 ms·

You need lots of transmission lines for that to work, and high voltage transmission is expensive to build, eats up land, and is opposed by every community it pa

by ch4s3 5y ago

You need lots of transmission lines for that to work, and high voltage transmission is expensive to build, eats up land, and is opposed by every community it passes through. I’m 100% in favor of lots of renewable use, but it’s not always a great use of land, prevents rewilding (with solar), and in the case of solar uses a ton of water. The latter being a major concern in arid regions. A lot of nuclear’s cost comes from shifting/overly tight regulation, legal prohibition of reprocessing, legal prohibition for long term storage, and graft. The latter will be a problem with large scale renewables once they’re large enough.

kwhitefoot 5y ago
We have a lot of the transmission lines already although of course we need more. The major missing part is interconnects between countries, or regions of large countries like the US. Germany has an over supply of renewable energy on occasion but is unable to export the energy so it simply drives the price negative in Germany while prices are high elsewhere.
- p_l 5y ago
  Germany pays neighbours to stop their own wind farms to sell power from their own, because they can't ship the energy from wind-rich north southwards due to lack of necessary interconnects. It's not that simple. And the overbuilding necessary is usually more in range of 10x assuming favourable storage conditions (which aren't necessarily available).
  - pfdietz 5y ago
    When I look at "Germany, 2011 weather data, 2030 cost assumptions" in https://model.energy/ https://model.energy/ I get an optimized solution (for synthetic baseload production) that has PV and wind curtailment at 4.6% and 12.3%, respectively. This solution includes batteries and hydrogen; generally when hydrogen is included curtailment is limited (because you can make hydrogen when the sources would have been curtailed, up to some point of sufficiently rare curtailment that the extra electrolysers don't make sense.)
    - p_l 5y ago
      This holds as long as hydrogen storage can be kept quite low (assuming no improvements in nuclear) i.e. you have plentiful underground caverns. Helps that the data they have on caverns is actually for germany. Mind you, the model misses things like "Bavaria is NIMBYing all necessary transit work" etc. which is why you have weird situation of Germany paying Netherlands to curtail wind farms while buying nuclear from France, because they have to route around NIMBYs. Only slightly related - I'd love if the cost comparisons in general discourse stopped avoiding the issue of intermittency (that's how you always get such low prices on wind and solar) and used costs that include capacity factor and dispatchability (which https://model.energy/ https://model.energy/ does). Having funding (and purchasing priority) decided on dispatchable green sources (whether hydro, wind/solar/battery/hydrogen mixes, or nuclear) would probably help a lot in stabilisation of grid and long term decarbonisation, even if it would reduce some frankly pathological incentives for renewable build out (pathological because of linked carbon-producing plant build out to stabilise the setup, while simultaneously using cheap peak production prices to push out stable setups)
      - pfdietz 5y ago
        That site may overestimate the cost of dealing with intermittency, since it doesn't include dispatchable demand. For example, if hydrogen is to be used in steelmaking or ammonia synthesis, that demand can also be added when renewables would otherwise be curtailed, and the hydrogen stored for later use. The site's model also does not include pumped hydro, or intermediate term thermal storage. All these extra options can only help reduce the cost of integrating renewables, and make renewables more competitive vs. nuclear.
        ephbit 5y ago
        > ... dispatchable demand. For example, if hydrogen is to be used in steelmaking or ammonia synthesis, that demand can also be added when renewables would otherwise be curtailed, and the hydrogen stored for later use. Isn't the problem that electrolyzers mostly have to run 24/7 because they would otherwise not be profitable? Then all these processes that rely on hydrogen wouldn't actually belong to the dispatchable demand category. Dispatchable demand could be found in heat pumps (in combination with buffer tanks) for heating homes. (As long as there's sufficient grid capacity)
- ch4s3 5y ago
  This is both a political problem and an energy sovereignty issue. You could turn Libya into solar Russia, but would you want to do that? My other concern is that such a complex and interconnected system is likely to be fragile in unexpected ways. And none of this addresses the land area required for base load solar.
  - ephbit 5y ago
    > ... concern is that such a complex and interconnected system is likely to be fragile in unexpected ways. I second that. The robustness of the current global energy supply system based largely upon solid, liquid and gaseous fuels stems from its flexibility and inherent buffering capability and the fact that lots of the connections/links are loose/weak/interchangeable. (Supplier of fuel xy can be chosen relatively spontaneously, completely unlike some cable which invariably connects two fixed geographic locations.) An intercontinental electrical grid is in comparison dramatically less flexible. I'd call it grossly negligent to even attempt to implement a world spanning grid exceeding lets say 15 % of total power transmission.
bryanlarsen 5y ago
You're right about the transmission lines. Land use of required solar is only a few hundred square miles in the US. Not a big deal. Nuclear's biggest cost is just that the US is very bad at doing big projects. Just the steam turbine in a nuclear plant is enough to make nuclear uneconomical, that's why coal plants are so much more expensive than natural gas.
- ch4s3 5y ago
  That’s because solar produces a tiny fraction of our energy mix. Replacing a single average US reactor with solar would require something like 200 square miles. Nuclear’s problem is badly written regulation and insane environmental review policies. That and the one off nature of their construction. We need to standardize and rewrite regulation based on probabilistic risk rather than worst case scenario planning and the linear non-threshold model.
  - bryanlarsen 5y ago
    I mistook. Enough solar for the US is a 200x200 mile square. Still fairly insignificant, much less than the amount of land dedicated to parking lots.
    - ch4s3 5y ago
      NREL estimates 14,000,000 acres or 22,000 square miles to go 100% solar, or the entire Mojave desert.
      - pfdietz 5y ago
        So, about 1.4% of the total area of agricultural land in the US.
        ch4s3 5y ago
        Yeah, which is a ton. You necessarily need to put it somewhere sunny, connectable to transmission, serviceable by roads, you need water, and it can't be too cold or hot for reasons of efficiency. The space and logistics aren't trivial.

by ch4s3 5y ago

kwhitefoot 5y ago

We have a lot of the transmission lines already although of course we need more. The major missing part is interconnects between countries, or regions of large countries like the US. Germany has an over supply of renewable energy on occasion but is unable to export the energy so it simply drives the price negative in Germany while prices are high elsewhere.

p_l 5y ago
Germany pays neighbours to stop their own wind farms to sell power from their own, because they can't ship the energy from wind-rich north southwards due to lack of necessary interconnects. It's not that simple. And the overbuilding necessary is usually more in range of 10x assuming favourable storage conditions (which aren't necessarily available).
- pfdietz 5y ago
  When I look at "Germany, 2011 weather data, 2030 cost assumptions" in https://model.energy/ https://model.energy/ I get an optimized solution (for synthetic baseload production) that has PV and wind curtailment at 4.6% and 12.3%, respectively. This solution includes batteries and hydrogen; generally when hydrogen is included curtailment is limited (because you can make hydrogen when the sources would have been curtailed, up to some point of sufficiently rare curtailment that the extra electrolysers don't make sense.)
  - p_l 5y ago
    This holds as long as hydrogen storage can be kept quite low (assuming no improvements in nuclear) i.e. you have plentiful underground caverns. Helps that the data they have on caverns is actually for germany. Mind you, the model misses things like "Bavaria is NIMBYing all necessary transit work" etc. which is why you have weird situation of Germany paying Netherlands to curtail wind farms while buying nuclear from France, because they have to route around NIMBYs. Only slightly related - I'd love if the cost comparisons in general discourse stopped avoiding the issue of intermittency (that's how you always get such low prices on wind and solar) and used costs that include capacity factor and dispatchability (which https://model.energy/ https://model.energy/ does). Having funding (and purchasing priority) decided on dispatchable green sources (whether hydro, wind/solar/battery/hydrogen mixes, or nuclear) would probably help a lot in stabilisation of grid and long term decarbonisation, even if it would reduce some frankly pathological incentives for renewable build out (pathological because of linked carbon-producing plant build out to stabilise the setup, while simultaneously using cheap peak production prices to push out stable setups)
    - pfdietz 5y ago
      That site may overestimate the cost of dealing with intermittency, since it doesn't include dispatchable demand. For example, if hydrogen is to be used in steelmaking or ammonia synthesis, that demand can also be added when renewables would otherwise be curtailed, and the hydrogen stored for later use. The site's model also does not include pumped hydro, or intermediate term thermal storage. All these extra options can only help reduce the cost of integrating renewables, and make renewables more competitive vs. nuclear.
      - ephbit 5y ago
        > ... dispatchable demand. For example, if hydrogen is to be used in steelmaking or ammonia synthesis, that demand can also be added when renewables would otherwise be curtailed, and the hydrogen stored for later use. Isn't the problem that electrolyzers mostly have to run 24/7 because they would otherwise not be profitable? Then all these processes that rely on hydrogen wouldn't actually belong to the dispatchable demand category. Dispatchable demand could be found in heat pumps (in combination with buffer tanks) for heating homes. (As long as there's sufficient grid capacity)
ch4s3 5y ago
This is both a political problem and an energy sovereignty issue. You could turn Libya into solar Russia, but would you want to do that? My other concern is that such a complex and interconnected system is likely to be fragile in unexpected ways. And none of this addresses the land area required for base load solar.
- ephbit 5y ago
  > ... concern is that such a complex and interconnected system is likely to be fragile in unexpected ways. I second that. The robustness of the current global energy supply system based largely upon solid, liquid and gaseous fuels stems from its flexibility and inherent buffering capability and the fact that lots of the connections/links are loose/weak/interchangeable. (Supplier of fuel xy can be chosen relatively spontaneously, completely unlike some cable which invariably connects two fixed geographic locations.) An intercontinental electrical grid is in comparison dramatically less flexible. I'd call it grossly negligent to even attempt to implement a world spanning grid exceeding lets say 15 % of total power transmission.

bryanlarsen 5y ago

You're right about the transmission lines. Land use of required solar is only a few hundred square miles in the US. Not a big deal. Nuclear's biggest cost is just that the US is very bad at doing big projects. Just the steam turbine in a nuclear plant is enough to make nuclear uneconomical, that's why coal plants are so much more expensive than natural gas.

ch4s3 5y ago
That’s because solar produces a tiny fraction of our energy mix. Replacing a single average US reactor with solar would require something like 200 square miles. Nuclear’s problem is badly written regulation and insane environmental review policies. That and the one off nature of their construction. We need to standardize and rewrite regulation based on probabilistic risk rather than worst case scenario planning and the linear non-threshold model.
- bryanlarsen 5y ago
  I mistook. Enough solar for the US is a 200x200 mile square. Still fairly insignificant, much less than the amount of land dedicated to parking lots.
  - ch4s3 5y ago
    NREL estimates 14,000,000 acres or 22,000 square miles to go 100% solar, or the entire Mojave desert.
    - pfdietz 5y ago
      So, about 1.4% of the total area of agricultural land in the US.
      - ch4s3 5y ago
        Yeah, which is a ton. You necessarily need to put it somewhere sunny, connectable to transmission, serviceable by roads, you need water, and it can't be too cold or hot for reasons of efficiency. The space and logistics aren't trivial.