You already occasionally have to wait for solar panel deliveries. (depending on your location) By buying them for mining you effectively make others wait and not use them for moving off fosil fuels. Additionally, both solar panels and batteries still rely on mining actual limited materials, so every one used for crypto effectively means one less for useful purposes in a long run.

I don't really follow - 3090s are below £1000 each, you hit 2000W power consumption with just 4 of them, so £4000 on GPUs. 2000W panels + battery is going to be at least £15-20k at current prices. Not sure why affording one would mean being able to afford the other.

2000Wh power station can be had for <$2k and 2000W solar panels for ~$2k. 3090s don't really consume 500W, more like 350W and that assumes regular voltages; in reality for mining it's much lower. 3080Ti would be even cheaper for about the same throughput.

Yeah but you have the rest of the system to account for. And you need more than just what the system uses to charge the battery storage for overnight use - probably 4000W of panels if not 6kW. The batteries are the most expensive part of this(unless you only want to run the system for few hours during the day, but then what's the point?). You mentioned a 2000Wh power station, but I'm not sure how that helps? That will only store enough energy for an hour of running at most. So yeah, you're looking at about £15k for the whole power system alone.