There's this incredible project to build a 10GW solar farm in Morocco (1/3 of UK peak consumption) and bring the power to the UK via HVDC cable. Amazingly they estimate only 10% losses despite being over 3800km long:
In the worst case, couldn't the excess power simply be used in electrolyzers to generate hydrogen? They may not be very efficient but it's better than throwing free energy away.
https://xlinks.co/morocco-uk-power-project/
Surely HVDC links between Scotland and England could be built?
And then there are pumped hydropower storage project like this one with a proposed storage capacity of 200 GWh and 1.5GW of power:
https://www.coireglas.com
In the worst case, couldn't the excess power simply be used in electrolyzers to generate hydrogen? They may not be very efficient but it's better than throwing free energy away.