Electrolytic hydrogen can be cheap as long as 1) electricity for electrolysis is cheap and 2) electrolyzers are cheap. 1) is reasonably easily assured by shavin

Electrolytic hydrogen can be cheap as long as 1) electricity for electrolysis is cheap and 2) electrolyzers are cheap. 1) is reasonably easily assured by shaving off overgeneration of electricity from renewable power plants. 2) is a matter of electrolyzer R&D, although it's true that it's slightly complicated by the former solution of 1) by decreasing their duty cycle. Nevertheless, 1) is the dominant problem. As for storage, it's true that storing hydrogen is problematic but once I calculated that even existing facilities for natural gas in, say, Germany would be sufficient for a whole month of the whole country's grid running off of hydrogen. This is less than the several months provided by using the same storage for natural gas, but since in the following decades, the demand for this gas is going to shrink severely as German buildings are going to be replaced by low-energy buildings (pursuant to the 2010/31/EU Energy Performance of Buildings Directive and the 2012/27/EU Energy Efficiency Directive, as well as presumably future regulations), this capacity might be freed up, and in any case it's a much larger capacity than is predicted to be required (https://www.sciencedirect.com/science/article/pii/S0014292118301107 https://www.sciencedirect.com/science/article/pii/S001429211...) for a 100% renewable grid in Germany. One interesting idea I don't know the feasibility of but is tempting anyway is ultra-large-scale liquid hydrogen storage. Considering the square-cube law and low density of liquid hydrogen stressing the structure (just 70 kg per cubic metre of liquid hydrogen tank, as opposed to 1000 kg per cubic metre of a water tank, for example), ultra-large-scale storage of hydrogen could be feasible in principle -- certainly much more than for example liquid hydrogen storage for a car, and in industrial settings to boot (as opposed to cars handled by ordinary citizens).