Seems a possible Aiden, but I believe, so I have read, the electrolysers
have a 30% loss. Then when converted to a fuel cell, another 30% loss
of 70%, so we need N reversable electrolysers ca[able of running the
country and recharging the batteries with N times a days supply for
N still days.
It seems a very costly solution to try and prevent what happened in Europe.
What would happen to the wholesale cost of electricity ?
I suspect, without actually knowing, this is why the UK Govt is
ordering small reactors from Rolls Royce.

Bazz,
Two 30% losses would be much closer to 50% than 70%. But I've heard elsewhere that the currently available electrolyses are closer to 80% efficient and the R&D teams are trying to reach 86% efficiency by 2030. Not that it matters that much - the input is cheap electricity and the output is expensive electricity, so even at much lower efficiency rates it would still be possible. Just to be clear: by "extensive electricity" I mean electricity at the times when the wholesale price is high, not electricity which is expensive to produce.

You underestimate the size of the overbuild that I, and many others, are envisaging. The batteries would not be charged from hydrogen, but from the solar and wind power that would otherwise be used to produce the hydrogen. Even on days that feel still, the wind turbines produce some electricity. Even on cloudy days, the solar panels produce some electricity.

So what would happen to the wholesale cost of electricity? The hydrogen industry would boost it at times of low demand, and cut it at times of high demand, so overall it would fall.

>It seems a very costly solution...
That's like saying CHP seems a very costly way to heat a building!

>... to try and prevent what happened in Europe.
No, that's NOT the objective. What happened in Europe is not even a threat in Australia. The objective s to get a reliable electricity supply from 100% renewables and to produce a lot of hydrogen (both for domestic industry and for export).

And UIVMM the UK Govt has so far only committed to funding R&D for the Rolls Royce small reactors. It hopes to order them in the future, and I hope it does, but I very much doubt nuclear power will ever be the cheap option its proponents like to pretend it is.