Sun, that’s such a nice pool, too bad you can’t get some use out of it.
Anyway, the tarp method will work, if you can secure it. With monsoon season coming, the high winds can send it into the neighbors yard.
Also as Kim mentioned, the warm water is going to be a breeding ground for algae.
I’m not sure what kind of pump you have, but you might be better off floating pucks for the summer, and running the pump for a few hours a day. You can then shut it down for the winter when the water is colder.