The point of hydrogen is not mainly energy storage but hydrogen is the only viable way to clean up two of the most carbon intensive industrial processes: steel smelting and ammonia (fertilizer) synthesis. Smelting steel requires coal to reduce the oxygen from raw iron to carbon dioxide. The coal can be replaced by hydrogen, which will then react to water vapor. Synthesizing ammonia needs elemental hydrogen which is as of now extracted from methane (natural gas) using steam reformation. This leads to CO2 as waste product whereas electrolysis crates hydrogen and oxygen directly/cleanly from water.

You need huge amounts of "base load" hydrogen generation capacities for these industries alone. Flexible generation, i.e. produce more to soak up excess renewable energy which you can then export or turn back into electricity (at a huge loss) later, is just the cherry on top.

The initial funding will absolutely come from the steel and chemical industry (and also government subsidies to get the transformation started).