It works but its very limited. But at the end of the day, it all comes down to your goals and intentions. If you just want to be fairly good, casual, its totally fine cause you can find your own way of learning things, of course, when learning by yourself its easier as age goes, your still 15 so its maybe not that easy. But still, very doable since you have some previous knowledge on music.
Now if you want to get serious at piano, everyone needs a good teacher except very few exceptions (there is always one), period.
Caio