I believe that is what I would be doing is AC coupling the 12KPV's load output to the 18KPV's gen input to "boost" the overall systems backup power during a grid down situation. Instead of being limited to to 12KW during grid down that could be bumped to 20KW with the addition of the 12KPV.
I...
@EG4_Jared could you answer the following: I'm sure it may have been covered but would you or anyone know if you could share 2 power pro batteries between the 18KPV and 12KPV with the 12KPV feeding the gen input of the 18KPV to boost the AC output in a grid down situation?