I suspect large-scale fixed installations are more likely to end up using some kind of flow battery: https://spectrum.ieee.org/green-tech/fuel-cells/its-big-an

I suspect large-scale fixed installations are more likely to end up using some kind of flow battery: https://spectrum.ieee.org/green-tech/fuel-cells/its-big-and-longlived-and-it-wont-catch-fire-the-vanadium-redoxflow-battery https://spectrum.ieee.org/green-tech/fuel-cells/its-big-and-... The big advantage there is independent scaling: peak discharge is tied to the total membrane area / pumping capability while capacity is tied to the amount of reactants that can be stored.