The need to restart server every so often to avoid excessive ram usage bit is very interesting to me. This sounds like some issue with memory management. Not necessarily a leak, but maybe something like server keeping unnecessary references so the object cannot be dropped.

Anyway, from my experience Rust developers love debugging such kind of problems. Are Lemmy Devs aware of this issue? And do you publish server usage logs somewhere to look deeper into that?

Just solar panels on your roof might not be enough. In my country it's a standard practice to wire things in such a way that when grid power goes out PV panels won't work either. Apparently ability to keep power during grid blackouts is significantly more expensive. So you might have solar setup and still be fucked during extreme weather.