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I'm interested in those alternative technologies, but I suspect they won't scale as well as batteries. Pumped hydro has been around a long time but it hasn't sc

I'm interested in those alternative technologies, but I suspect they won't scale as well as batteries. Pumped hydro has been around a long time but it hasn't scaled because it is just very geographically specific.

ncmncm 4y ago
Pumped hydro is far, far less geographically specific than always assumed. This is partly because it needs no watershed, and partly because transmission lines mean it need not be local. Anyway pumped hydro is only one of many equally viable alternatives. All will be used. Eventually which ones are cheapest will become clear.
- sanderjd 4y ago
  I think my assumption with pumped hydro is that there must be something holding it back because it's been mature for a long time, so if it were as useful and scalable as you say, I think it would have been scaled a lot more by now.
  - ncmncm 4y ago
    The overwhelming majority of utility-scale storage today is pumped hydro. It stores and releases many GWh every day. You don't hear much about it because it just works.
    - sanderjd 4y ago
      Yes but is still a small amount of energy relative to total demand and there don't seem to be serious efforts to scale it up massively. I don't claim to know why there aren't. Maybe there should be. It just makes me suspicious when I see a mature technology that still sees limited deployment, that there is a good reason for that.
ncmncm 4y ago
Batteries have the very large disadvantage that cost is per Wh stored. Flow batteries can reduce this, as capacity becomes a matter of tankage and electrolyte. The sweet spot for storage is near-zero opex, very low per-Wh stored capex, and cheap capex per-W in and, particularly, out. Thus, weight for watt-hours, and simple motor / generator for watts in and out. Synthetic fuel has the appeal that the stored energy is readily tanked and transported, and very saleable; enough so to overcome low round-trip efficiency, expensive electrolysers for W-in, and complicated combined-cycle turbines for W-out.

ncmncm 4y ago

Pumped hydro is far, far less geographically specific than always assumed. This is partly because it needs no watershed, and partly because transmission lines mean it need not be local. Anyway pumped hydro is only one of many equally viable alternatives. All will be used. Eventually which ones are cheapest will become clear.

sanderjd 4y ago
I think my assumption with pumped hydro is that there must be something holding it back because it's been mature for a long time, so if it were as useful and scalable as you say, I think it would have been scaled a lot more by now.
- ncmncm 4y ago
  The overwhelming majority of utility-scale storage today is pumped hydro. It stores and releases many GWh every day. You don't hear much about it because it just works.
  - sanderjd 4y ago
    Yes but is still a small amount of energy relative to total demand and there don't seem to be serious efforts to scale it up massively. I don't claim to know why there aren't. Maybe there should be. It just makes me suspicious when I see a mature technology that still sees limited deployment, that there is a good reason for that.

ncmncm 4y ago

Batteries have the very large disadvantage that cost is per Wh stored. Flow batteries can reduce this, as capacity becomes a matter of tankage and electrolyte. The sweet spot for storage is near-zero opex, very low per-Wh stored capex, and cheap capex per-W in and, particularly, out. Thus, weight for watt-hours, and simple motor / generator for watts in and out. Synthetic fuel has the appeal that the stored energy is readily tanked and transported, and very saleable; enough so to overcome low round-trip efficiency, expensive electrolysers for W-in, and complicated combined-cycle turbines for W-out.