Solar pool heating is very much an established thing, and it does eat up a good chunk of a roof. So yea, if the quantity of hot water is an issue, that would certainly be a good place to dump it.

On the other hand, pool water has chemistry which may make it unsuitable for using in combined panels. Especially if it's a salt water pool, you don't want that water anywhere near electronics. The typical pool solar heating panels are basically just thin black plastic that the water flows through.