4 ms·

Thermal storage has very poor discharge rates unfortunately (usually slower than a day), as well as surprisingly high cost once you factor in inefficiencies and

Thermal storage has very poor discharge rates unfortunately (usually slower than a day), as well as surprisingly high cost once you factor in inefficiencies and turbine cost

pfdietz 1y ago
As was repeatedly explained in that other thread, thermal storage of the kind described there is inherently a long term storage technology, and this drives the design to minimize capex, not maximize round trip efficiency. The focus on efficiency is fundamentally misplaced there, as it becomes orders of magnitude less important compared to diurnal storage (which batteries appear to be well on their way to dominating.) Long term storage and diurnal storage are complementary technologies, sort of like the different levels of cache and main memory in a computer memory hierarchy. Combining them appropriately reduces cost vs. using just one of them. Anyway, the technology as described would produce heat at 600 C for as little as $3/GJ, which nuclear would have a hard time competing with.
- deepnotderp 1y ago
  $3/GJ is $108/MWH which any large scale fission buildout would easily beat for thermal energy costs
  - pfdietz 1y ago
    You misplaced a decimal point. A MWH is 3.6 GJ, so it's $10.8/MWH. $3/GJ is about the current Henry Hub price for natural gas, and as you should know cheap natural gas like this is what killed the "nuclear renaissance" in the US.
    - deepnotderp 1y ago
      Oh my bad, you’re right Re: Nat gas, agreed, it’s not solar though, storage is much more expensive Thermal energy still needs to drive a turbine to generate electricity
      - pfdietz 1y ago
        Sure. 600 C is about the temperature of steam in a coal fired power plant, so one of the use cases here is to take an old coal plant and replace the heat source. It's much higher temperature than the steam in a LWR, so the turbine can be smaller and cheaper. Also, no steam generator is needed as in a PWR.
        deepnotderp 1y ago
        Yes but one of the reasons that coal is being replaced by gas is because of the capex of the steam turbine
        pfdietz 1y ago
        Yes? That doesn't mean the capex of a steam turbine for this application would be unaffordable, or that this wouldn't have superior economics to nuclear (which also has a steam turbine, and a more expensive one).

Thermal storage has very poor discharge rates unfortunately (usually slower than a day), as well as surprisingly high cost once you factor in inefficiencies and turbine cost

pfdietz 1y ago

As was repeatedly explained in that other thread, thermal storage of the kind described there is inherently a long term storage technology, and this drives the design to minimize capex, not maximize round trip efficiency. The focus on efficiency is fundamentally misplaced there, as it becomes orders of magnitude less important compared to diurnal storage (which batteries appear to be well on their way to dominating.) Long term storage and diurnal storage are complementary technologies, sort of like the different levels of cache and main memory in a computer memory hierarchy. Combining them appropriately reduces cost vs. using just one of them. Anyway, the technology as described would produce heat at 600 C for as little as $3/GJ, which nuclear would have a hard time competing with.

deepnotderp 1y ago
$3/GJ is $108/MWH which any large scale fission buildout would easily beat for thermal energy costs
- pfdietz 1y ago
  You misplaced a decimal point. A MWH is 3.6 GJ, so it's $10.8/MWH. $3/GJ is about the current Henry Hub price for natural gas, and as you should know cheap natural gas like this is what killed the "nuclear renaissance" in the US.
  - deepnotderp 1y ago
    Oh my bad, you’re right Re: Nat gas, agreed, it’s not solar though, storage is much more expensive Thermal energy still needs to drive a turbine to generate electricity
    - pfdietz 1y ago
      Sure. 600 C is about the temperature of steam in a coal fired power plant, so one of the use cases here is to take an old coal plant and replace the heat source. It's much higher temperature than the steam in a LWR, so the turbine can be smaller and cheaper. Also, no steam generator is needed as in a PWR.
      - deepnotderp 1y ago
        Yes but one of the reasons that coal is being replaced by gas is because of the capex of the steam turbine
        pfdietz 1y ago
        Yes? That doesn't mean the capex of a steam turbine for this application would be unaffordable, or that this wouldn't have superior economics to nuclear (which also has a steam turbine, and a more expensive one).