Hi,
I have 8*405w JA-Solar panels. I would expect at peak to get 3.2kW from this, obviously some loss is expected though.
I have the gen3 3.6kW inverter, so 'clipping' shouldn't be an issue?
What sort of loss would you expect and where would it 'show' in the app? eg, would I still see 3.2kW being generated from the panels and the outputs (to battery, to home and to grid) not adding up to the inputs, or would it be shown as the solar generation never reaching 3.2kW?
Timp You are not likely to see any clipping as the potential generation from your panels is well within the restrictions of your inverter. For a Gen 3 3.6 inverter you'd have to generate more than 3.6kW to see clipping, but it can probably handle up to 7kW of generation if you are charging the battery at the same time.
I have a Gen 1 3.6 inverter, the limitations are a bit more severe with a max generation of 2.8kW per string and 4.8kW total.
Generally if you have clipping the graph of PV production will show clipping as a flattish line at the top of the generation curve rather than a smother curve, for example:
This a plot from last summer (as we don't seem to have summer this year) string 1 can produce 3.2kW, but never does as the inverter can only take 2.8kW from it. String 2 can generate at least the same but is throttled so as not to exceed the 4.8kW. The line is uneven as the inverter manages the inputs but there is clipping between 11 and 3.
You'll see at 15:10 a sudden drop in string 2 output, this is because my battery was fully charged so the inverter could only use 3.68kW.
Here is one without clipping:
Thank you,
A week or so ago on a clear day I got this....
Which shows the generation stopped rising as the sun got higher at around 2.7kW, I would have expected it to get much closer to 3.2kW, does this suggest something is wrong?
I'd say that looks like clipping to me. If you hadn't written that you have a Gen 3 inverter I would have thought you'd got a Gen 1 inverter. It is a Gen 3 3.6 Hybrid inverter?
I'd be double checking that I had right inverter installed and be having words with my installer.
Timp I have 8*405w JA-Solar panels. I would expect at peak to get 3.2kW from this, obviously some loss is expected though.
Its not quite as simple as this. The output rating is based on a set of standardised conditions, e.g. sun directly overhead, 20 degrees centigrade temperature, etc. Things like the orientation of your panels, time of day and outside temperature will all affect the output.
The good news is that on colder sunny days like April and October you should be able to get slightly more from your panels than the theoretical maximum if they are South facing.
The screenshots you showed definitely indicate solar clipping is happening in the inverter. Get the installer to look at it
Thank you,
In the control panel it shows as...
Personally I feel like one of the panels might be not generating anything? 7 panels would give 2.83kW, which minus the sort of loss I would expect gives pretty much what I'm seeing.
Timp would it give that flat top, though?
(You could get clipping if you forced a battery export at the same time, since that would increase the AC generation.)
Timp Do you have a USB modem hanging out the bottom of your inverter?
Are all these panels on one string?
Watcher No, its plugged into the LAN
Vestas Yes
Timp That's your problem then. You'll never see more than 2.8kW from your panels as that's (IIRC) the per-string limit.
Vestas Except the datasheet for the Gen 3 inverter says 'Max. DC Input Power (per string) 7.5kWp'
Well I phoned Octopus and gave them all the info, waiting for them to get back to me
SJB Its clipping at 2.8kW which indicates a string limit so something has either been set wrong or its not a G3.
Edit - the OP is probably hitting the current limit for the string, which appears to be 11A (G1); 13A (G2); 15A (G3).
Timp what firmware number is it running? (Available from portal.) I think should be a definitive proxy for the model of inverter.
DD
Label on the side of it says "GIV-HY-3.6-G3"
Timp That's old firmware I think. Does the portal not show updates available?
It doesn't seem to, it had an update last month I think
Looking through some Facebook groups it appears that D0.393-A0.393 is the factory firmware for the gen 3 hybrid inverter and you should be upgraded, I'd speak to your installer or give GivEnergy support a call and ask to be put on the latest release firmware. However, to be honest, I don't know if that'll fix your issue as I have an AC3.0 inverter.