This website made me reconsider if 99.9999% SLA and always online is really that important for lots of websites. I used to self-host my own server in my own apartment, but gave up on that after my internet provider had their first major outage that lasted almost a week. Also I didn’t want to worry about the fire hazard, or the server going down when I was traveling etc.
But a solar powered server seems interesting, if the batteries could be made fire safe.
This website is like 10 years old from memory, well before grid-scale batteries were widespread (well they still aren’t in many countries).