do i need to register a new invertor

[Spectral]

our old invertor failed so we had a new one installed by a licenced installer but ever since we are not generating the solar power we used to. we have 21 panels. we have had the installer return and check with no improvment, please help

[NeilC]

Inverters are simply an electronic device and convert DC (from the solar panels) in AC.

By LAW the replacement inverter must have the same specifications as the one that failed.

If the new inverter is same specs should be no issues.

If the installer has come back and rechecked the new inverter then it must be OK.

I don't know where you live, but in Adelaide SA, our solar output has been down in output about 30% for the same period (June) last year due to very overcast skies (and with no rain).