0w PV during the day

At the moment it is very grey and raining quite a bit here. My system is showing 0w PV all day so far, I don't think I've ever seen that before during day light hours?

Short strings?

kram Not sure what that means? It is now at 2.1kW as the sun is out at last

chris_p I think it was questioning how many panels you had on each inverter string. Fewer panels need more light to reach the threshold at which the inverter can use the energy.

Tim Ah ok, thanks for that explanation. 6 x 2 is what we have.

There is a required startup voltage on at least one string before the inverter can start generating, Gen1 = 120 Vdc and Gen2 = 150 Vdc.

If you do not have many panels on a string then they need a higher insolation level to reach the required startup voltage in order to wake up the inverter.
Each solar panel generates around 30 to 40 Volts and are wired in series on the string in order to obtain the required voltage for the inverter (much like multiple 1.5 Volt batteries to get a 3.0V or 6.0V supply).
More panels on a string means a higher voltage for the same insolation level.