I don't think hydrogen is a good energy storage solution. I do see its advantage over hydrocarbons for certain applications but the difficulties in storing hydr

I don't think hydrogen is a good energy storage solution. I do see its advantage over hydrocarbons for certain applications but the difficulties in storing hydrogen - a small molecule which is sort of an escape artist - make it less than ideal for many purposes. Fuel cells can get contaminated unless they're run with pure hydrogen and oxygen. In applications where hydrogen is already available - e.g. H₂-LOX fuelled rockets - it makes sense to use fuel cells. It might be possible to run aircraft using H₂-fed fuel cells if these can be made powerful and light enough to fit the application, the advantage over battery-electric here is that the energy density of liquid hydrogen is much higher than that of current battery technology. For the rest - cars being a good example - I think batteries are currently a better solution. Large scale energy storage is probably handled better using either redox flow batteries [1], hydro storage systems or energy storage vaults using concrete blocks which are lifted when there is too much energy available, lowered when energy is needed. [1] https://en.wikipedia.org/wiki/Flow_battery https://en.wikipedia.org/wiki/Flow_battery