4 ms·

Sure, as long as you skip storage. Batteries are really expensive if you're using enough to get through windless nights instead of just compensate the duck curv

Sure, as long as you skip storage. Batteries are really expensive if you're using enough to get through windless nights instead of just compensate the duck curve. Long-distance transmission is expensive too, and to get through winter you need either huge storage or lots of overcapacity. It all adds up. At this point someone usually says "we don't need batteries for long-term storage, we can just make hydrogen and burn it later" but then oops, you're back to using a turbine.

ncmncm 4y ago
It is correct that batteries are the most expensive storage. One corrolary is that other storage is cheaper. Another is that other methods will be used instead. Storage is an integral part of a renewable-powered grid. It is figured into all the cost analyses. Insisting otherwise is promoting known falsehoods. Lying is unwelcome here.
- DennisP 4y ago
  Hence my second paragraph. The only other major option is using pumped hydro for storage, but not every region has the geography for it.
  - ncmncm 4y ago
    Pumped hydro is very far from the only alternative to batteries. But you have been told that before, too.
    - DennisP 4y ago
      "Hence my second paragraph" which was this: > At this point someone usually says "we don't need batteries for long-term storage, we can just make hydrogen and burn it later" but then oops, you're back to using a turbine. There are various experimental options too but I don't think any have deployed at scale, so their costs are uncertain. And some of them, like thermal storage, will still use a turbine.
      - ncmncm 4y ago
        Turbines cost less to operate part-time than full-time. One operated 4 hours / day, or one day / week, costs a lot less than one run continuously.
        DennisP 4y ago
        I'm gonna need a source on that. It seems to me that turbine cost is mainly capital cost, and if you're not running it continuously then your cost per kWh is higher. After all, that's the argument you renewables folks make when you say nuclear plants can't load-follow economically. So tell me why a turbine run intermittently is cheaper, and prove it with a source.
        ncmncm 4y ago
        Allow me to invite you to look up steam turbine overhaul cost and frequency. Do mothballed turbines need frequent overhauls? Or will they need overhauls after N hours' use at intensity Y, or after M > N operated at intensity X < Y? Steam turbines are a substantial fraction of nuke operating cost, but far from the only substantial cost.
        DennisP 4y ago
        An idle turbine also isn't earning revenue. I haven't found specific numbers on steam turbines, but this pdf says a gas turbine's maintenance cost over 30 years is 3 to 4 times the capital cost: https://www.gasturbine.org/papers/GTA%20Comments%20on%20RMRR.pdf https://www.gasturbine.org/papers/GTA%20Comments%20on%20RMRR... So taking the worst case, capital plus maintenance for a continually-running turbine is 5X its capital cost, to get 30 years of power output. For each year of power, the total cost is 5/30 or 1/6 of the capital cost. Now lets take your 4 hours/day example. That's 1/6 as much running time, so only 5 total years of power output. It's also 1/6 as much maintenance cost, so maintenance is 4/6 of the capital cost, for a 30-year total cost of 1.66 times capital cost. Total cost per year of power is 1.66/5 = 1/3 of the capital cost. That puts the cost per kWh for energy storage at double the cost of the continuously-run turbine.
lambdatronics 4y ago
Not the same kind of turbine. Internal combustion turbines are more cost-effective than steam turbines.
- DennisP 4y ago
  Right, steam turbines cost about 50% more. But a turbine for energy storage is likely to get a much lower capacity factor than a turbine on a generator, so it evens out. (Sources and math in another thread below my above comment.)

ncmncm 4y ago

It is correct that batteries are the most expensive storage. One corrolary is that other storage is cheaper. Another is that other methods will be used instead. Storage is an integral part of a renewable-powered grid. It is figured into all the cost analyses. Insisting otherwise is promoting known falsehoods. Lying is unwelcome here.

DennisP 4y ago
Hence my second paragraph. The only other major option is using pumped hydro for storage, but not every region has the geography for it.
- ncmncm 4y ago
  Pumped hydro is very far from the only alternative to batteries. But you have been told that before, too.
  - DennisP 4y ago
    "Hence my second paragraph" which was this: > At this point someone usually says "we don't need batteries for long-term storage, we can just make hydrogen and burn it later" but then oops, you're back to using a turbine. There are various experimental options too but I don't think any have deployed at scale, so their costs are uncertain. And some of them, like thermal storage, will still use a turbine.
    - ncmncm 4y ago
      Turbines cost less to operate part-time than full-time. One operated 4 hours / day, or one day / week, costs a lot less than one run continuously.
      - DennisP 4y ago
        I'm gonna need a source on that. It seems to me that turbine cost is mainly capital cost, and if you're not running it continuously then your cost per kWh is higher. After all, that's the argument you renewables folks make when you say nuclear plants can't load-follow economically. So tell me why a turbine run intermittently is cheaper, and prove it with a source.
        ncmncm 4y ago
        Allow me to invite you to look up steam turbine overhaul cost and frequency. Do mothballed turbines need frequent overhauls? Or will they need overhauls after N hours' use at intensity Y, or after M > N operated at intensity X < Y? Steam turbines are a substantial fraction of nuke operating cost, but far from the only substantial cost.
        DennisP 4y ago
        An idle turbine also isn't earning revenue. I haven't found specific numbers on steam turbines, but this pdf says a gas turbine's maintenance cost over 30 years is 3 to 4 times the capital cost: https://www.gasturbine.org/papers/GTA%20Comments%20on%20RMRR.pdf https://www.gasturbine.org/papers/GTA%20Comments%20on%20RMRR... So taking the worst case, capital plus maintenance for a continually-running turbine is 5X its capital cost, to get 30 years of power output. For each year of power, the total cost is 5/30 or 1/6 of the capital cost. Now lets take your 4 hours/day example. That's 1/6 as much running time, so only 5 total years of power output. It's also 1/6 as much maintenance cost, so maintenance is 4/6 of the capital cost, for a 30-year total cost of 1.66 times capital cost. Total cost per year of power is 1.66/5 = 1/3 of the capital cost. That puts the cost per kWh for energy storage at double the cost of the continuously-run turbine.

lambdatronics 4y ago

Not the same kind of turbine. Internal combustion turbines are more cost-effective than steam turbines.

DennisP 4y ago
Right, steam turbines cost about 50% more. But a turbine for energy storage is likely to get a much lower capacity factor than a turbine on a generator, so it evens out. (Sources and math in another thread below my above comment.)