It is pretty common for a solar pool heater to wrap around to an adjacent roof when there is not enough space on one roof surface to get the needed coverage. Plumbing connects the two banks together as if it is a single system on one roof. As long as the height of each bank of panels is the same, the plumbing is quite simple.

Here is a recent Cape Coral, FL installation on two roofs with a total of 13 solar panels.