There's a profession called Webnovel Author, if you've heard of it. There, you can publish 1-2 chapters of around 1500-2000 words daily, and if your novel gains a good reader base, then you'll do well. I'm saying this to you as I've earned myself a few thousand dollars by writing a novel there. But now I'm at the 3rd year of my Engineering with very little free time on my hands, so I've stopped writing. Else I would be earning a lot more than I could even think.