In reply to Paul Crusher R:
You can get solar panels in good condition from “Bimble Solar” second hand at a decent price.
Your problem with solar is the asbestos roof - can’t see anyone wanting to drill it. So a new roof it is! If doing it new use inset panels without slates under them to save materials and time. I’ve got 5 “solar slates” on a log store; they look great and I’d do the garage roof with them, but they’re very expensive compared to new or used conventional panels.
”Build Your Dreams” (I know) are doing a reasonably priced 48 volt lithium battery system that’ll work with Victron inverter/chargers to give you grid tied/feed in/self consumption + grid redundant 240 V AC power from the solar. Unlike the Tesla stuff it looks very DIY friendly. It’ll integrate wind etc.
I know little about wind but there are permitted development rights if it’s MCS compliant. Small turbines look simple enough to integrate electronicall but beware vibration.
Streams - I’ve been looking in to a run off the river system with pelton wheel for seasonal (5 months around winter solstice) generation. Not very expensive or complex in itself, although I haven’t yet identified a grid tie hydro inverter that can play nice controlling power output in “off grid” island mode. What sinks it for me is the cost of legal compliance with water extraction (even if you put it back...) and environmental paperwork. So far it’s a time cost - a lot of hours research and I still feel I don’t have a bloody clue...
Any 240V system should comply with building regs, on grid or not. If you grid tie you need to comply with EREC G83 or possibly G59. Chances are that means paying a knowledgable sparky for some of the work or for certification.
Beware cheap high power Chinese inverters available for seemingly unreal prices on amazon, flea bay etc. The isolation between the solar ground and the 240 V AC is shockingly bad. Literally.