Neglecting that we actually study and know how fast large batteries degrade with age and time, and thusly know that they do last far more than ten years, it does actually matter that hydrogen is to expensive to make with excess green energy and that no company is willing to buy it precisely because green hydrogen made from excess green energy is so many times more expensive to make then grey hydrogen.

If it is saves more money to electrify and save wear and tear on equipment by shutting down when there is an excess power than could ever be made by making and selling green hydrogen with it, people arn’t going to make much green hydrogen. Put another way, green hydrogen being so expensive that even with free electricity it is still too expensive to compete is a problem for green hydrogen.

Maybe raising taxes on grey hydrogen to the point green hydrogen can compete might be worth it, but that is a very different solution to a very different problem then what you originally claimed, which was that there wasn’t enough demand for hydrogen.

Indeed given the actual problem facing green hydrogen, which is that it is too expensive to produce compared to the more common grey hydrogen, increasing demand for hydrogen is actually directly harmful to the planet from a global warming perspective.