Maybe not a service in the typical sense, but setting up your router+server to route your home network traffic through a VPN is a fun project.
My router (MikroTik) supports WireGuard, so I can use it with Mullvad for the whole house---but wg is demanding and it's a slow router, so while it can NAT at ~1Gbps, it can't do WireGuard at more than ~90Mbps. So, I set up WireGuard/Mullvad on a little SBC with a fast processor, and have my router use that instead. Using policy based routing and/or mangling, I can have different VLANs/subnets/individual hosts selectively routed through the VPN.
It's a fun exercise, not sure I implemented it in a smart way, but it works :)
200MWh is about 1/100 of Little Boy, the atomic bomb dropped on Hiroshima.
Compressed air can get out all at once given the right circumstances.
Storing energy in a way that can go boom is something I'd be a little scared of, were I a nearby resident. I'm sure thermal batteries can have gnarly failure mechanisms but I would way rather live near one of those than a giant compressed air cylinder.