5 ms·

> Use all the excess solar/wind to create fuel for the natural gas plants I don't know what the efficiency of the process described in TFA, but from Wikipedia

> Use all the excess solar/wind to create fuel for the natural gas plants I don't know what the efficiency of the process described in TFA, but from Wikipedia I see that Electricity->Gas->Electricity has an efficiency of 30-40%. There are other alternatives like pumped hydro stations that are way more efficient.

weq 4y ago
And destroy the earth. Hydro is not green energy, its an energy tradeoff. nuclear is much greeener then hydro. with nuclear, its only a possibility of screwing the environment. with damns, its garenteed.
- peterashford 4y ago
  How are you seeing hydro "destroying the earth?". New Zealand has a lot of hydro and we don't appear to be destroyed, as of yet
  - Schroedingersat 4y ago
    Hydro makes major changes to the local ecosystem and kills a lot of wildlife that can't breathe water. Although p\enty of things can live in a dam they're not what was there before. It also makes major changes downstram People like to equivocate this with making entire countries uninhabitable or ongoing destruction. It also requires vast quantities of concrete (and thus has high one time emissions) We should still avoid it where we can now that we know better.
    - ncmncm 4y ago
      This is not true at all. Hydro power dams use up a watershed, but those are not being built for storage systems. Pumped hydro storage does not consume a watershed or harm wildlife or fisheries. Pumped hydro does not need concrete for construction. Please do not repeat this falsehood.
      - Schroedingersat 4y ago
        Please show me a funded or built project (or even a plausible proposal or projection from past and current projects) in the global north that has a lower cost per capacity than Fengning Pumped Storage Station that has the following properties: - Is at a site of a type that is available with over 100x the capacity of fenging (ie. a hill with a dirt berm would count if there are 4000GWh of hills that could be plausibly used somewhere). If it does this it will help, but is still several orders of magnitude shy of replacing fossil fuels. - Fulfils your criteria about not destroying an ecosystem. - Is not built on top of a past project unless there are enough of whatever the past project is to fulfll criterion 1 (ie. a quarry or mine is fine if there are many similar mines or a handful of immense ones) or the cost of repeating the project elsewhere is included. - Can empty its reserves in 2 months - Doesn't take up a prohibitive amount of surface area (is at least 20kWh/m^2 or at most 10x the size of a solar array to fill it). - Has an operating cost under $30/MWh of stored and produced energy Otherwise pumped hydro does not meaningfully exist as it cannot beat batteries (the thing that is a long way from being good enough to replace fuels) or must destroy a watershed or other ecosystem.
        ncmncm 4y ago
        There is no need for batteries to "replace fuels". Batteries are useful in places, but fuels, soon sythetic fuels, will continue to be used, particularly for shipping and aviation. There is no need for pumped hydro to "beat batteries". Both will be used. There is no shortage of land to use for elevated reservoirs, and (again) no implied threat to watersheds in building them. There is no need for "at least 20 kWh/m^2". Reservoirs have many uses that all add value. They may store energy and water, provide recreation, habitat, irrigation, and a site for solar, all at once. There is no need for them to store 2 months' power. There is very little economy of scale: a dozen reservoirs are as good as one. Construction cost is not proportional to capacity. At worst, it goes as the square root, to build the perimeter dike. Extraction rate is a question of how big and how many Pelton wheels attached to generation equipment you care to install. And, as always, immediate and local cost will dictate choice. There is no need for universal numbers or a single answer for everybody.
    - philwelch 4y ago
      > Hydro makes major changes to the local ecosystem and kills a lot of wildlife that can't breathe water. It’s not that great for river fish, either.
- ncmncm 4y ago
  Nobody is building hydro dams anymore, because there is noplace left to build them. Many are being razed, instead, to try to restore fisheries. But pumped hydro is a completely different proposition. Meanwhile, each dollar diverted to nukes from building out solar+wind+storage brings climate catastrophe nearer. The immediate cause for catastrophe will be global thermonuclear war triggered by ... more subtle ... effects of the change.
- dvirsky 4y ago
  Nuclear can't store solar energy, I'm only talking about giant scale energy store, not generation itself. I'm all for nuclear FWIW.
Schroedingersat 4y ago
There are not enough sites for pumped hydro. Chemical energy is dense, easy to store, and you need methane for stuff like fertilizer. Solar energy is basically free ($30/MWh and falling rapidly). The solutions we'lp use are the ones which scale and the ones which are cheapest for storage as it will be much more expensive than the energy. For storing for a day, that's probably sodium batteries as the cost per MWh through is lowest. For storing for a year, you want to minimize cost per MWh stored. Right now this looks like methane, maybe hydrogen or for heating, thermochemical batteries.
- ncmncm 4y ago
  > There are not enough sites... This is always claimed, and is always false. Please do not repeat falsehoods. Existing hydro generation needs a watershed. Pumped hydro does not. All it needs is a disused hilltop and earthen dike, and not always the dike. It doesn't always need the hill: underground cavities work to pump water up out of, and to drain into. Batteries will always be the most expensive alternative. They will be used in limited amounts, mainly for very short-term (overnight) storage.
  - Schroedingersat 4y ago
    > It doesn't always need the hill: underground cavities work to pump water up out of, and to drain into. Do you have any good numbers on real world projects? I'm very happy to be wrong here, but all the numbers I can find are either lies from nuclear shills or using existing watersheds. Most also only focus on the cost per kW which is higher than batteries and not the relevant metric (as batteries can drain in a few minutes) for season-long storage. Also a quick back of the envelope seems to suggest emptying and filling lake Baikal could store as much energy as about a billion tonnes of chemical storage. This seems like a reasonable upper bound which would indicate pumped hydro is about an order of magnitude short of solving the problem. Current battery production is nowhere near (total cumulative seems to be about a megatonne chemical equivalent even if it is more than doubling annually it'll take over a decade to catch up), but this is expected because batteries are optimal for short term. Overall by gut feel it seems a more feasible to make and store ten cubic kilometers of chemical fuel worldwide than move 200,000km^3 of water around.

weq 4y ago

And destroy the earth. Hydro is not green energy, its an energy tradeoff. nuclear is much greeener then hydro. with nuclear, its only a possibility of screwing the environment. with damns, its garenteed.

peterashford 4y ago
How are you seeing hydro "destroying the earth?". New Zealand has a lot of hydro and we don't appear to be destroyed, as of yet
- Schroedingersat 4y ago
  Hydro makes major changes to the local ecosystem and kills a lot of wildlife that can't breathe water. Although p\enty of things can live in a dam they're not what was there before. It also makes major changes downstram People like to equivocate this with making entire countries uninhabitable or ongoing destruction. It also requires vast quantities of concrete (and thus has high one time emissions) We should still avoid it where we can now that we know better.
  - ncmncm 4y ago
    This is not true at all. Hydro power dams use up a watershed, but those are not being built for storage systems. Pumped hydro storage does not consume a watershed or harm wildlife or fisheries. Pumped hydro does not need concrete for construction. Please do not repeat this falsehood.
    - Schroedingersat 4y ago
      Please show me a funded or built project (or even a plausible proposal or projection from past and current projects) in the global north that has a lower cost per capacity than Fengning Pumped Storage Station that has the following properties: - Is at a site of a type that is available with over 100x the capacity of fenging (ie. a hill with a dirt berm would count if there are 4000GWh of hills that could be plausibly used somewhere). If it does this it will help, but is still several orders of magnitude shy of replacing fossil fuels. - Fulfils your criteria about not destroying an ecosystem. - Is not built on top of a past project unless there are enough of whatever the past project is to fulfll criterion 1 (ie. a quarry or mine is fine if there are many similar mines or a handful of immense ones) or the cost of repeating the project elsewhere is included. - Can empty its reserves in 2 months - Doesn't take up a prohibitive amount of surface area (is at least 20kWh/m^2 or at most 10x the size of a solar array to fill it). - Has an operating cost under $30/MWh of stored and produced energy Otherwise pumped hydro does not meaningfully exist as it cannot beat batteries (the thing that is a long way from being good enough to replace fuels) or must destroy a watershed or other ecosystem.
      - ncmncm 4y ago
        There is no need for batteries to "replace fuels". Batteries are useful in places, but fuels, soon sythetic fuels, will continue to be used, particularly for shipping and aviation. There is no need for pumped hydro to "beat batteries". Both will be used. There is no shortage of land to use for elevated reservoirs, and (again) no implied threat to watersheds in building them. There is no need for "at least 20 kWh/m^2". Reservoirs have many uses that all add value. They may store energy and water, provide recreation, habitat, irrigation, and a site for solar, all at once. There is no need for them to store 2 months' power. There is very little economy of scale: a dozen reservoirs are as good as one. Construction cost is not proportional to capacity. At worst, it goes as the square root, to build the perimeter dike. Extraction rate is a question of how big and how many Pelton wheels attached to generation equipment you care to install. And, as always, immediate and local cost will dictate choice. There is no need for universal numbers or a single answer for everybody.
  - philwelch 4y ago
    > Hydro makes major changes to the local ecosystem and kills a lot of wildlife that can't breathe water. It’s not that great for river fish, either.
ncmncm 4y ago
Nobody is building hydro dams anymore, because there is noplace left to build them. Many are being razed, instead, to try to restore fisheries. But pumped hydro is a completely different proposition. Meanwhile, each dollar diverted to nukes from building out solar+wind+storage brings climate catastrophe nearer. The immediate cause for catastrophe will be global thermonuclear war triggered by ... more subtle ... effects of the change.
dvirsky 4y ago
Nuclear can't store solar energy, I'm only talking about giant scale energy store, not generation itself. I'm all for nuclear FWIW.

Schroedingersat 4y ago

There are not enough sites for pumped hydro. Chemical energy is dense, easy to store, and you need methane for stuff like fertilizer. Solar energy is basically free ($30/MWh and falling rapidly). The solutions we'lp use are the ones which scale and the ones which are cheapest for storage as it will be much more expensive than the energy. For storing for a day, that's probably sodium batteries as the cost per MWh through is lowest. For storing for a year, you want to minimize cost per MWh stored. Right now this looks like methane, maybe hydrogen or for heating, thermochemical batteries.

ncmncm 4y ago
> There are not enough sites... This is always claimed, and is always false. Please do not repeat falsehoods. Existing hydro generation needs a watershed. Pumped hydro does not. All it needs is a disused hilltop and earthen dike, and not always the dike. It doesn't always need the hill: underground cavities work to pump water up out of, and to drain into. Batteries will always be the most expensive alternative. They will be used in limited amounts, mainly for very short-term (overnight) storage.
- Schroedingersat 4y ago
  > It doesn't always need the hill: underground cavities work to pump water up out of, and to drain into. Do you have any good numbers on real world projects? I'm very happy to be wrong here, but all the numbers I can find are either lies from nuclear shills or using existing watersheds. Most also only focus on the cost per kW which is higher than batteries and not the relevant metric (as batteries can drain in a few minutes) for season-long storage. Also a quick back of the envelope seems to suggest emptying and filling lake Baikal could store as much energy as about a billion tonnes of chemical storage. This seems like a reasonable upper bound which would indicate pumped hydro is about an order of magnitude short of solving the problem. Current battery production is nowhere near (total cumulative seems to be about a megatonne chemical equivalent even if it is more than doubling annually it'll take over a decade to catch up), but this is expected because batteries are optimal for short term. Overall by gut feel it seems a more feasible to make and store ten cubic kilometers of chemical fuel worldwide than move 200,000km^3 of water around.