Hydrogen is part of the answer, for steel and perhaps concrete manufacturing. And also to fuel container ships, in the form of ammonia. But as a storage medium it is not very efficient. At least not now.

Round-trip efficiency is not very important for a backup storage medium when the marginal cost to produce is zero.

Other considerations drive choices, then, e.g. capex, transportability, usefulness for other processes.

And once you realize that nearly all renewable energy production has a marginal cost of zero, then it quickly becomes the overwhelmingly best idea for energy storage.

The infrastructure needed for hydrogen production and storage is far, far, from zero.

Yet, the marginal cost of producing hydrogen using that infrastructure is zero: the only inputs are water and energy, and the marginal cost of that energy is zero.

Will be fantastic when we have all those hydrogen production plants who only run with 30% utilization because they only make sense when you massively overproduce renewables.

To "massively overproduce" renewables is cheap. Build more, get more, sell the overproduction.

> To "massively overproduce" renewables is cheap.

No it actually isn't really.

> Build more, get more, sell the overproduction.

You will have to pay to get ride of it in many places. Chemical plants want reliable electricity to have reliable production.

Hint: there is no cost to disposing of excess solar and wind energy.

When you produce chemicals yourself, you may operate on a schedule of your own choosing.