A solar powered web server. May be offline if it's not sunny in Barcelona.
https://solar.lowtechmagazine.com/power.html
@mathew What about at night, surely these things would have battery backup
One way round this could be to build an on site gym, open 24/7 so anyone using the gym would also generate back up power for the web server.
@zleap Hamster wheels, tiny generator.
