One of my favourites things to fiddle with are home web servers. In fact the oldest post from this site (ported from previous websites) was about this very subject. This has always been a “minimal cost” hobby, in that I have tried to use old hardware I already have, and free services for things like domain names. The only thing I wasn’t getting for free with these setups was the electricity. So I wondered, by accepting a small initial outlay, whether it was possible to create a server with zero ongoing running costs.
Just recently I purchased a Raspberry Pi Zero and used it to create my latest web server. At the moment it is running from the mains electricity, but I am planning in the near future to try and run the thing on solar power alone. Anyway, I will probably write more about the project on the site being run by the Raspberry Pi at some point. You can check out the site here.