My neighbor has one, I will ask him tomorrow what kind it is

There are many other ways to control the electricity. You can also use them. For this, you can take help from a roofer.

You could probably make your own if you are really into DIY. I'm sure it can be done.

You could probably get a second hand version of it online.

You can also find them on eBay.

What is the voltage of the panel? In any case, 15 watts is pretty small for this. The 7 amp charge controller is pretty powerful on the other hand.

Missing is the panel voltage, the battery voltage, and the current drawn by the fan. Also how many hours a day do you expect to operate the fan. Finally, where are you located and how many hours of direct sun can you expect per day.

I'd get a 12 volt battery, size depends on the above missing info. And a 15 volt panel, again size depends on the above info.

solar panel installation

I'd like to see this Ceiling fan, but the link doesn't show a ceiling fan, and I can't find it on Google. Sounds very interesting, though. Every little bit helps...