It's just an AGM lead acid battery and a charger. I pulled the charger out of an old RV. I estimate I'll get over 10 hours runtime from it, since I used a 115 amp hour battery.
A few solar panels wouldn't be hard to add, but I'm not currently running off grid.
Backups every 30 min to 3 continents and a single stable VM. No cloudflare, CDNs, etc. This gives me plenty uptime and I haven't felt the need to add redundant webservers.
DNS is replicated to 4 DDoS protected VPSs and I have never had a DNS related outage when using my own DNS clusters...