Simplz, generate electricity from Green Energy sources (Wind/Solar/Wave) & use national grid to transmit to plants to
generate H2 by electrolysis.
Store the H2 in the form of Ammonia (NH3), which is a *lot* easier to store & if necessary transport, than H2.
There's existing technology & infastructure to do this.
Crack NH3 to release H2 when required to generate electricity where & when required via H2 Fuel Cells, or even better by NH3 Fuel Cells.
No Carbon in the above cycle, therefore no Carbon capture required.
Biting the hand that feeds IT
