I once basically did just that, besides the image dithering. I ran a small blog off a Raspberry Pi, only using Markdown files and something to render them to HTML. I used my own IP address, which I know you're not technically supposed to do but in 15 years I've never had an ISP crack down on me for it, and had a script that would run periodically to update the A record for my domain in Route 53. (since my IP was dynamic)

Whether you're doing it for energy purposes or not, it's a fun project because it feels a bit like sticking it to the man, since we're used to always hosting our sites on someone else's machine.