3 ms·

Other comment chains have explained the storage scale you claim is needed, isn't a great estimate. Energy conservation is probably a better payback than either

by dv_dt 3y ago

Other comment chains have explained the storage scale you claim is needed, isn't a great estimate. Energy conservation is probably a better payback than either nuclear or renewables and better resilience for people infrastructure. For example, better insulation reduces energy costs in both cold winters and heat waves, and reduces the impact if there are grid/source failures by any technology. It also doesn't have a big crossover on the logistics tail of either nuclear or renewables, and so is a great thing to do in parallel to address climate change in general. "Conservation is an admission of failure" is a purely ridiculous position.

Manuel_D 3y ago
The estimate of 12 hours of storage was one of the more optimistic ones. It's not just day/night cycles there's also weather that results in long term fluctuations in output. Some of the estimates call for weeks of storage. Energy conservation is likely not going to be feasible as more and more transportation gets electrified, as gas heating is replaced with electric, and industrial processes like smelting are decarbonized. Conservation is indeed an admission of failure, because success involves accommodating the growing demand for electricity in the future. Remember, electricity production is only about a third of total energy consumption: https://www.eia.gov/energyexplained/us-energy-facts/ https://www.eia.gov/energyexplained/us-energy-facts/
- Retric 3y ago
  Estimates for weeks of storage are made by people who don’t understand the fundamental cost optimization going on. More production costs X which reduces the need for batteries by Y, as long as X > Y you build more production even if most of it’s output is unnecessary. Also 16% of global electricity comes from hydroelectric generation, we really don’t need that many batteries. Actual optimized energy storage is on the order of 2 to 6 hours total globally ~30 years from now depending on how much prices drop. With larger numbers representing lower battery prices. In the shorter term it’s a tiny fraction of that.
  - Manuel_D 3y ago
    2-6 hours is nowhere near enough to offset daily fluctuations, let alone seasonal fluctuations. Overproduction only gets you so far, unless this proposal also involves transoceanic HVDC cables. Hydropower is not exactly the same thing as storage: you can stop releasing water and build up the reservoir, but you cannot pump water up river. Even just 6 hours of storage -which would not be sufficient even with several factors of overproduction - is 15,000 GWh of storage to satisfy present global electricity use.
    - Retric 3y ago
      Overproduction means you don’t ever see daily fluctuations you have a surplus every single day of the year. Unless storage gets insanely cheap that’s by far the cheapest safe option. Hydropower dams are already storage. When you don’t release the water it’s saved until you do. If you have enough rain from 3 months ago to release 10 MW 24/7 over a week then you also have enough water to release 15 MW for 12 hours and 5 MW for the other 12 every day etc. You can’t save 100% of the water or the river downstream runs dry but the minimum is generally well below the average flow rate. This isn’t unusual, most dams ramp production up and down to maximize the value of the stored water.
      - Manuel_D 3y ago
        > Overproduction means you don’t ever see daily fluctuations you have a surplus every single day of the year. No, this is not even remotely true. No amount of solar overproduction will let you produce energy at night. 12 hours a day (on average, depend on the season) you will not have any production regardless of overproduction. You'll have a lot of excess energy during the day, but still no energy when the sun has set. Infinity times zero is still zero. Not unless you create transoceanic HVDC cables that connect Eurasia to the Americas, literally piping electricity from one side of the world to the other. Wind also has windless days, with more extreme seasonal fluctuations. Overproduction is not a silver bullet that eliminates the need for storage. Just because you have net surplus over the course of a 24-hour period does not mean demand was satisfied at all times. This is why intermittent sources are so challenging. > Hydropower dams are already storage. When you don’t release the water it’s saved until you do. But you can only save energy at the rate that rainfall refills the dam. If you have a dam that refills at a rate of 10MW, you can only effectively store 10MW of excess energy. If you have 20MW of excess production, you can still only store 10MW and the other 10 MW is wasted. Dams are not batteries, they can store a lot of energy but they can only be refilled at the rate dictated by rainfall. You also can't completely shut off a dam or the river will run dry with serious ecological consequences, and impairing downstream water supply.

by dv_dt 3y ago

Manuel_D 3y ago

The estimate of 12 hours of storage was one of the more optimistic ones. It's not just day/night cycles there's also weather that results in long term fluctuations in output. Some of the estimates call for weeks of storage. Energy conservation is likely not going to be feasible as more and more transportation gets electrified, as gas heating is replaced with electric, and industrial processes like smelting are decarbonized. Conservation is indeed an admission of failure, because success involves accommodating the growing demand for electricity in the future. Remember, electricity production is only about a third of total energy consumption: https://www.eia.gov/energyexplained/us-energy-facts/ https://www.eia.gov/energyexplained/us-energy-facts/

Retric 3y ago
Estimates for weeks of storage are made by people who don’t understand the fundamental cost optimization going on. More production costs X which reduces the need for batteries by Y, as long as X > Y you build more production even if most of it’s output is unnecessary. Also 16% of global electricity comes from hydroelectric generation, we really don’t need that many batteries. Actual optimized energy storage is on the order of 2 to 6 hours total globally ~30 years from now depending on how much prices drop. With larger numbers representing lower battery prices. In the shorter term it’s a tiny fraction of that.
- Manuel_D 3y ago
  2-6 hours is nowhere near enough to offset daily fluctuations, let alone seasonal fluctuations. Overproduction only gets you so far, unless this proposal also involves transoceanic HVDC cables. Hydropower is not exactly the same thing as storage: you can stop releasing water and build up the reservoir, but you cannot pump water up river. Even just 6 hours of storage -which would not be sufficient even with several factors of overproduction - is 15,000 GWh of storage to satisfy present global electricity use.
  - Retric 3y ago
    Overproduction means you don’t ever see daily fluctuations you have a surplus every single day of the year. Unless storage gets insanely cheap that’s by far the cheapest safe option. Hydropower dams are already storage. When you don’t release the water it’s saved until you do. If you have enough rain from 3 months ago to release 10 MW 24/7 over a week then you also have enough water to release 15 MW for 12 hours and 5 MW for the other 12 every day etc. You can’t save 100% of the water or the river downstream runs dry but the minimum is generally well below the average flow rate. This isn’t unusual, most dams ramp production up and down to maximize the value of the stored water.
    - Manuel_D 3y ago
      > Overproduction means you don’t ever see daily fluctuations you have a surplus every single day of the year. No, this is not even remotely true. No amount of solar overproduction will let you produce energy at night. 12 hours a day (on average, depend on the season) you will not have any production regardless of overproduction. You'll have a lot of excess energy during the day, but still no energy when the sun has set. Infinity times zero is still zero. Not unless you create transoceanic HVDC cables that connect Eurasia to the Americas, literally piping electricity from one side of the world to the other. Wind also has windless days, with more extreme seasonal fluctuations. Overproduction is not a silver bullet that eliminates the need for storage. Just because you have net surplus over the course of a 24-hour period does not mean demand was satisfied at all times. This is why intermittent sources are so challenging. > Hydropower dams are already storage. When you don’t release the water it’s saved until you do. But you can only save energy at the rate that rainfall refills the dam. If you have a dam that refills at a rate of 10MW, you can only effectively store 10MW of excess energy. If you have 20MW of excess production, you can still only store 10MW and the other 10 MW is wasted. Dams are not batteries, they can store a lot of energy but they can only be refilled at the rate dictated by rainfall. You also can't completely shut off a dam or the river will run dry with serious ecological consequences, and impairing downstream water supply.