This is actually on my longer term plans. I already have some hardware for running my servers on solar power, but its a bit more complicated to get everything set up and the grid power I am currently using is mostly wind and geothermal anyway (as in... literally because those power plants are very near).

Distributing file storage could be already done via a newer version on Pictrs and Garage but currently the Pictrs instance is proxied by the Lemmy backend, so you can't fully utilize the potential of a distributed file storage backend by serving images directly to users from it (CDN like).

However, figuring out a way to distribute the main PostgreSQL database might be more complicated (there is CockroachDB, but the licensing terms are not FOSS...).

Other than that, you really just need some sort of script to link login to the solar protocol and it should work.