What I think is going on is the installer won the bid, installed cheap or substandard equipment took the money and put the numbers on line monitoring so it all looked real good.
On line monitoring shows 12.4kWp installed, nameplate is 18.3kWp. Last years total was 14300kWh.
Using 14300/12.4=1193kWh, better than all local systems
Using " " /18.3= 793kWh worse than all local systems.
I asked the dealer and he tells me its a different way to measure something about...