PV output fluctuations

[logslogs]

I have a Growatt on-grid 15kw inverter that's not producing smooth graphs with many small dips over the day. I thought this was normal until I saw a friend's graphs and they were rather smooth.

This is on a normal clear day with no shade/clouds etc. It's the same thing daily.

Please see the screenshot. I have noticed similar fluctations on MPPT voltage too that keeps varying.

Is this normal and what could be causing it?

 

[MisterSandals]

Not enough info to answer.
Are your systems identical equipment?
Are the battery charge states and loads identical?

 

[logslogs]

This is an on-grid/grid-tied inverter so no batteries.

Systems aren't identical. My friend is using a different inverter but at the same 7kw size and in the same area.

So I am not sure if my inverter is faulty or is it something else.

 

[DIYrich]

Squirrel. Pesky birds.

Just a possibility: time window of each data point. If you have a shorter window for each data point, you may be showing the actual minute by minute variation.

Otherwise, can you see production by MPPT? It may show if a string has a problem panel.

 

[logslogs]

Thanks for the suggestions. Not many birds around and definitely no squirrels

The wifi module is configured to send data every 5 minutes so it's unlikely it's minute by minute.

Does anything look wrong here in attached screenshots? One for MPPT voltage and another for MPPT power.

 

[logslogs]

Some more graphs attached.

Can anyone tell me if this is normal or if anyone else's graphs look like this.