Oh yes, no argument there. We're already using absolutely huge amounts of hydrogen that are mostly made from fossil fuels right now. Worldwide hydrogen production is responsible for more greenhouse gas emissions than the entire country of Germany. We'll have to turn that into green hydrogen and use a ton of renewable energy for that. If we make use of surplus wind and solar, it will help a lot with stabilizing the grid.
What I was thinking of was the idea of producing hydrogen through electrolysis, storing it and later turning it back into electricity through fuel cells. And I'm not sure if that will ever be cheaper and more efficient than newer and cheaper battery technologies like sodium ion or redox flow batteries.