Hi Les

Varying panels are possible but not recommended. Depending on the size of system, panels can receive varying amounts of sunlight hitting the array, so varying amounts of output from each panel will not upset your system.

That said, the specification or full ‘peak out’ put of such a system will never be fully reached, so you could be short changing yourself by accepting such a system, not only output wise but financially too.

Best practice determines all panels be the same wattage and specified to a maximum peak out. Anything less than that is short change.