[mrpopo]

To give an idea of the order of magnitude of inefficiency :

* Currently a grid => hydrogen => grid round trip is 40-45% efficient.

* A grid => battery => grid round trip is 90-95% efficient.

You can recover 2x more energy by NOT using hydrogen. There is no competition. Unless the lost energy from green hydrogen production can be recovered somehow (co-generation)...

[natmaka]

Green hydrogen is produced thanks to electricity produced by renewables (wind, solar...) when it is useless (not immediately consumed). It's a "use it or lose it" situation: using it, even at a loss, seems sound.

Many applications (transportation, industry...) can use it as such, without any way from hydrogen to electricity, and more and more probably will.

There are surprising new ways (offering an impressive efficiency), such as: https://www.slb.com/newsroom/press-release/2021/pr-2021-1118...

At a glance: https://www.energy.gov/eere/fuelcells/hydrogen-production-el...

In-depth take: https://assets.siemens-energy.com/siemens/assets/api/uuid:53...

[marmarama]

I have no doubt that batteries will also form part of the grid energy storage solution. But they don't scale as well as hydrogen and have higher maintenance costs and replacement rates.