Re: Wind and solar @steviebuk
Sure. There are problems with this of course, although I think at large scale the intent is to store and transport it as Ammonia rather than pure Hydrogen. More losses on conversion, but much less volatile and easier to keep in a tank.
My point is that Hydrogen, for all its faults, is the only energy store that can be drained by repurposing existing infrastructure. There's a pragmatism to this approach I find reassuring. And I agree that Hydrogen in ICE or (worse) blue hydrogren is just stupid - I'm only talking about grid-scale use.
As for efficiency, the very page you link to (thanks, interesting) talks of new electrolyzers theorised about 90% efficiency, and 60% from burning in a CCGT. Pumped storage by contrast is 80%, so you're not a million miles away. Yes those electrolyzers are still in development, but then we're also a long way from surplus electricity from renewables too.