3 ms·

If grid battery prices fall another 90% (on trend, this will be in 10 - 15 years, and there is no reason to think that it cannot happen), the economics will pro

If grid battery prices fall another 90% (on trend, this will be in 10 - 15 years, and there is no reason to think that it cannot happen), the economics will probably be different. Need to skate where the puck's going, not where it is.

pfdietz 4y ago
Hydrogen costs about $1/kWh of energy storage capacity when stored underground in solution mined caverns in salt formations, so that's a tough target for batteries to reach. Even a 10x reduction will not get them there. The higher efficiency of batteries also becomes proportionally less important as the cost of renewable energy itself declines. It will be interesting to see where the crossover point between hydrogen (and other e-fuels) and current batteries lies. There are also technologies that will fall between them, including certain battery technologies with low current density (Form Energy's batteries are in this category) and various flavors of thermal storage. The latter has the possibility of shifting over to reheat with hydrogen in emergency situations when the directly stored heat is exhausted.
- adgjlsfhk1 4y ago
  you also have to factor in the cost of the hydrogen to burn which for green hydrogen isn't cheap.
  - pfdietz 4y ago
    As I already pointed out, for the last few percent this doesn't matter much, as the cost of the energy there is dominated by the capital cost of the storage system, not the cost of the fuel being burned.
  - ZeroGravitas 4y ago
    In a world where you are trying to cover the last few percent of zero carbon generation, green hydrogen wil be cheap enough to be used to make alcohol, plastics and a bunch of other things just because it's cheaper than natural gas or other feedstocks. So it's not really a worry, prices for grey/blue and green hydrogen should crossover this decade.
- ben_w 4y ago
  I think there's something missing here. Is that the price per unit stored, or the price per unit of capacity to store? Batteries cost $120/kWh of initial capacity, but they can be recharged between hundreds and multiple thousands of times before significant degradation, depending on the specific design? Picking x1000 arbitrarily, that adds 12¢ to the cost of electricity that goes via a battery today (a lot to be sure, but significantly less than the average domestic cost here). I think hydrogen electrolysis is about 60-90% efficient, so 1/0.9 to 1/0.6 times the electricity cost to make as gas (assuming the hardware cost is amortised to the point of being negligible), but that isn't as high as $1/kWh even for domestic electricity prices here in Germany. Square cube law implies large scale storage will be much cheaper than small scale storage, so I'm still expecting that to be lower than $1/kWh as delivered, though I can believe it might cost that to build the capacity.
  - ncmncm 4y ago
    Battery cost is on the same downward trend as everything else, with new chemistries subtracting step functions. (Watch iron/air, zinc/bromine, antimony/calcium.) But for bulk storage, there are still cheaper technologies that cost only per MW to store or extract, not per MWh stored, like batteries. Tankage is cheap. The per-MW cost is for motor-generators attached to hydro turbine, air compressor, or winch; or for nitrogen liquifier and turbine; or for electrolyser and fuel cell or combined-cycle turbine. Storing in transportable tanks affords extra revenue opportunities.
    - ben_w 4y ago
      I don't think that answers my question. I think the stated prices may mean something other than what they look like they mean.
      - ncmncm 4y ago
        Cost for motor/generators is not changing, but the tech is extremely mature. Costs for electrolysers and fuel cells are both falling fast. Air compression and liquidation are both mature technologies, but might respond to a massive increase in usage by getting cheaper. A survey of storage technology pilot projects show people doing much more expensive versions of each than will be deployed. The incentives for pilot projects favor over-complex systems based on over-complex processes described in papers that had to be that to get academic attention as novel, and grants likewise. When civil engineers get involved, systems will get radically simpler and cheaper. Probably designs will trade off efficiency, as the cost for a little extra power is much less than for complexity.
- ZeroGravitas 4y ago
  I think Form Energy batteries and that whole category of cheap long term storage that gets turned back into electricity (including, controversially, pumped hydro) are a dead end. The random element breaks their already fragile cost justification. Hydrogen generation makes sense because it's a physical product that you can use for other things if you don't burn it, which acts as insurance. A buffer for your buffer. Heat batteries can have predictable loads and don't need the return trip to electricity. Lithium and PV have a daily rhythm of usage which covers the higher price. And throwing some energy away most of the year if there's no demand can still make financial sense if it's needed for rare peaks. In general, building more renewables and doing the above is cheaper than trying to store energy and convert it back to electricity (unless you do it once or twice a day to amortise the cost). This is why the climate change deniers go on and on about storage. They have correctly identified that it doesn't make financial sense to use batteries for that last few percent, but ignored all the other, better cheaper options to focus on that totally unnecessary approach. And also that the other 90% are better, cleaner and cheaper so we have money to burn on solutions if we needed it. The cheaper renewables get, the less the Form battery sales pitch works. Just build more generation and short term storage.
  - ncmncm 4y ago
    Throwing away energy will probably not be a thing once the factories for hydrogen and ammonia generating equipment and desalination equipment have ramped up. H2, NH3, and clean H2O are so useful there will always be a market for as much as you can produce at zero marginal cost. I.e., once you have the equipment, which you needed anyway, it makes no sense to operate it less than you can afford to, even when the price of those drops to near nothing.
    - ZeroGravitas 4y ago
      You could argue that running those systems at anything less than 100% capacity is just another kind of waste, which would be true. It's all just trade-offs. Generating energy that isn't used, or not using assets to their full capacity is just something to deal with based on costs and benefits. We have plenty of waste and slack in the world today, and renewables seem likely to radically reduce that, so no point getting caught up in worrying about minor inefficiencies. 10 steps forward, one step back is still forward motion.

pfdietz 4y ago

Hydrogen costs about $1/kWh of energy storage capacity when stored underground in solution mined caverns in salt formations, so that's a tough target for batteries to reach. Even a 10x reduction will not get them there. The higher efficiency of batteries also becomes proportionally less important as the cost of renewable energy itself declines. It will be interesting to see where the crossover point between hydrogen (and other e-fuels) and current batteries lies. There are also technologies that will fall between them, including certain battery technologies with low current density (Form Energy's batteries are in this category) and various flavors of thermal storage. The latter has the possibility of shifting over to reheat with hydrogen in emergency situations when the directly stored heat is exhausted.

adgjlsfhk1 4y ago
you also have to factor in the cost of the hydrogen to burn which for green hydrogen isn't cheap.
- pfdietz 4y ago
  As I already pointed out, for the last few percent this doesn't matter much, as the cost of the energy there is dominated by the capital cost of the storage system, not the cost of the fuel being burned.
- ZeroGravitas 4y ago
  In a world where you are trying to cover the last few percent of zero carbon generation, green hydrogen wil be cheap enough to be used to make alcohol, plastics and a bunch of other things just because it's cheaper than natural gas or other feedstocks. So it's not really a worry, prices for grey/blue and green hydrogen should crossover this decade.
ben_w 4y ago
I think there's something missing here. Is that the price per unit stored, or the price per unit of capacity to store? Batteries cost $120/kWh of initial capacity, but they can be recharged between hundreds and multiple thousands of times before significant degradation, depending on the specific design? Picking x1000 arbitrarily, that adds 12¢ to the cost of electricity that goes via a battery today (a lot to be sure, but significantly less than the average domestic cost here). I think hydrogen electrolysis is about 60-90% efficient, so 1/0.9 to 1/0.6 times the electricity cost to make as gas (assuming the hardware cost is amortised to the point of being negligible), but that isn't as high as $1/kWh even for domestic electricity prices here in Germany. Square cube law implies large scale storage will be much cheaper than small scale storage, so I'm still expecting that to be lower than $1/kWh as delivered, though I can believe it might cost that to build the capacity.
- ncmncm 4y ago
  Battery cost is on the same downward trend as everything else, with new chemistries subtracting step functions. (Watch iron/air, zinc/bromine, antimony/calcium.) But for bulk storage, there are still cheaper technologies that cost only per MW to store or extract, not per MWh stored, like batteries. Tankage is cheap. The per-MW cost is for motor-generators attached to hydro turbine, air compressor, or winch; or for nitrogen liquifier and turbine; or for electrolyser and fuel cell or combined-cycle turbine. Storing in transportable tanks affords extra revenue opportunities.
  - ben_w 4y ago
    I don't think that answers my question. I think the stated prices may mean something other than what they look like they mean.
    - ncmncm 4y ago
      Cost for motor/generators is not changing, but the tech is extremely mature. Costs for electrolysers and fuel cells are both falling fast. Air compression and liquidation are both mature technologies, but might respond to a massive increase in usage by getting cheaper. A survey of storage technology pilot projects show people doing much more expensive versions of each than will be deployed. The incentives for pilot projects favor over-complex systems based on over-complex processes described in papers that had to be that to get academic attention as novel, and grants likewise. When civil engineers get involved, systems will get radically simpler and cheaper. Probably designs will trade off efficiency, as the cost for a little extra power is much less than for complexity.
ZeroGravitas 4y ago
I think Form Energy batteries and that whole category of cheap long term storage that gets turned back into electricity (including, controversially, pumped hydro) are a dead end. The random element breaks their already fragile cost justification. Hydrogen generation makes sense because it's a physical product that you can use for other things if you don't burn it, which acts as insurance. A buffer for your buffer. Heat batteries can have predictable loads and don't need the return trip to electricity. Lithium and PV have a daily rhythm of usage which covers the higher price. And throwing some energy away most of the year if there's no demand can still make financial sense if it's needed for rare peaks. In general, building more renewables and doing the above is cheaper than trying to store energy and convert it back to electricity (unless you do it once or twice a day to amortise the cost). This is why the climate change deniers go on and on about storage. They have correctly identified that it doesn't make financial sense to use batteries for that last few percent, but ignored all the other, better cheaper options to focus on that totally unnecessary approach. And also that the other 90% are better, cleaner and cheaper so we have money to burn on solutions if we needed it. The cheaper renewables get, the less the Form battery sales pitch works. Just build more generation and short term storage.
- ncmncm 4y ago
  Throwing away energy will probably not be a thing once the factories for hydrogen and ammonia generating equipment and desalination equipment have ramped up. H2, NH3, and clean H2O are so useful there will always be a market for as much as you can produce at zero marginal cost. I.e., once you have the equipment, which you needed anyway, it makes no sense to operate it less than you can afford to, even when the price of those drops to near nothing.
  - ZeroGravitas 4y ago
    You could argue that running those systems at anything less than 100% capacity is just another kind of waste, which would be true. It's all just trade-offs. Generating energy that isn't used, or not using assets to their full capacity is just something to deal with based on costs and benefits. We have plenty of waste and slack in the world today, and renewables seem likely to radically reduce that, so no point getting caught up in worrying about minor inefficiencies. 10 steps forward, one step back is still forward motion.