If a house already has a PV array and wishes to expand it using the CGHP, we have to model the existing array in the existing home and "ADD" a second array in the upgrades with a min 7 KW (5 KW min). The array upgrade should trigger. We were successful in doing this.
The only error we now see on the portal is what should be the array at 5000$, comes out as another upgrade for the same 5000$ amount.
In the example below: existing PV = 5KW on "Power Gen" tab, add the the TOTAL PV KW on the upgrade main screen

you would have identical data for the first PV system in both existing and upgrades

And then we simply add the NEW array on the second tab on the UPGRADE only.

Enter numbers in the second array that would add up to a 5KW array:
Array area: 421 ft2 Slope: estimate roof slope in degrees Azimuth: 0 is South, 45 is Southeast or Southwest, 90 is East or West Module Type: User Specified Module Efficiency: 18.5% Temp: 109F Coefficient: 0.27 Misc Losses: 5% Other Losses: 0% Inverter Efficiency: 98% Grid Absorption: 100%