@carl99, just pondering this one a bit more. I think the best thing you can do now is find a good installer, as they should be able to walk you through all of these considerations. Where about in Spain are you? @matlindley got an install near Granada I believe, recently. Would you recommend the installers @matlindley, and do you know if they are a national company, or just local? It would be good to have a few recommended installers in southern Spain, as seems there is plenty of interest in solar down there.
Ah, I see you said Murcia. Not too close to Granada, but not too far. Might be relevant.
Off-grid - BYD, Victron Quattro quote review - Granada, Spain