Losing Solar panel generation input

Good morning all. Hoping that somebody out there can help with an issue I seem to have with solar generation in the mornings.
A few basics; 4.6 kW over 12 panels. 3.6 kW inverter. 2x 5.2 kilowatt batteries

1. We had the system installed a few weeks ago but over the last week with the sunshine all day every day I am noticing something strange. All is well up until around 9 AM, panels are producing steadily up to 1.1 kW and then all of a sudden something is happening and the solar input reduces to around 40 W with absolutely no change environmental conditions, just full on sunshine with no areas of shade. Then raises to around 160 to 170 W and stays there for a while, it's been steady at 175 W for 55 minutes so far this morning and I am estimating this figure should be way way higher. The last couple of days the generation has improved again eventually but I'm not convinced we are getting the full monty in terms of generation for the rest of the day.

My thought is that somehow the inverter doesn't like things and throws a wobbly and throttles back what it will allow through into the batteries?
Does anybody have any ideas or has anyone heard of a similar situation. Thanks very much indeed

Cloud9 Presumably you've got a east-facing array? I'm guessing that the issue is one of two things: either there's some "under the hood" (ie you might not be aware of) automation happening; or the system is performing perfectly but your portal/app data isn't changing.

My advice is to restart the inverter (portal - inverter card - power button at the top right) and then reset to defaults (portal - inverter card - settings - Reset to Defaults - Submit at the bottom). This should clear all your settings back to defaults, putting the inverter into ECO mode (minimising grid import/export and diverting surplus solar to battery). Check that ECO is enabled and that timed settings are all disabled and that you have no automations set (Octopus R&D?).

You can check back in the inverter card - inverter data (3x3 matrix top right by restart button) for previous days data. That would indicate whether the anomaly you are seeing is the inverter shutting down, or the indication going askew.

Tim And if you still have a problem, please post an image of your power flows graph from your portal dashboard so we can see in a bit more detail whats happening. You might also like to look in detail at the generation data in the portal - check the string voltages and currents the inverter is handling. These might indicate a problem with your installation. Maybe a panel is failing and bringing everything down. Look in the Inverter Panel and select PV data

Tim
OK thanks. I have restarted the inverter and There is no automation going on but I have reset the default as you suggested. It is definitely in eco mode as well.
It is all south facing but generating very well by around 0900. Looks like it is back up to speed again now. If it happens again tomorrow i'll be in touch with the installers!
Thanks for guiding me around the system. There's a very a lot to learn😳

cluelesscris
Does this help at all? It shows the sudden drop at around 9 AM

I had a similar issue where the panels would be generating just enough to cover the house... By forcing the battery to be charged in the app... I was seeing the generation jump up. Biggest increase I saw was around 600w to over 3kw... just by telling it to charge the battery.

As soon as I set it back to normal... the extra generation would drop off and over the next 5 mins or so... reduce to just above the house use.

Then my dongle seemed to fail... and it took about 9 days to get that all sorted, replaced and the system recommissioned again. I also had a wifi extender installed to improve wifi to the garage where everything is installed.

Since then... the problem hasn't resurfaced... So I don't know if something was changed by the installers or if the dongle was misreporting data really badly.

Cloud9

Power graph also

Cloud9 My generation graph is similar to yours from 8-11 had an early spike but at 9:35 it dropped from 2.9kw down to 400w and then fluctuated in the 400-900w range for a while, spiked up 2.2kw for 10-20mins, the dropped back again... and about 11:10 it rose again to over 3kw... where it's fluctuated ever since. data shows it'll drop to sub 1kw for 10-20 mins then rise up again.

medium cloud cover here... but it's thin/high cloud... still managed to get battery to 92% so far and drawn from it when generation was lower than house.

Seems to be working just fine here for these conditions

Anomnomnomaly
I think if it does it again tomorrow it's time to ask questions

Cloud9 @Anomnomnomaly FWIW, assuming high wind and cloud cover are not causing the spikes (ie sun brightness was largely constant), I'd get your installers back. VPV1&2 are both increasing as you might expect with a rising sun moving towards the array plane but IPV1&2 both collapse. This sound to me like a poor connection; one that gets hot and then present a high resistance and it's happening on both strings which sounds ominous. I'd like to think it's a poor connection somewhere along the string but because it appears to be affecting both strings at the same time, I wonder if it's something internal to the inverter? Anyways, the installer can check the connections to the inverter, after that, it'll be down to Givenergy to investigate.

Tim

Mine was definitely cloud cover, I'm sat here looking out the window and we've had light and high cloud drifting across all day... Still produced around 10kwh so far today and it's only 3pm... I'll expect to be around 11-12kwh by 5ish

Anomnomnomaly
What's the capability of your array in kilowatts? Hope you don't mind me asking

Cloud9 4kw + 5.2kwh

Actually saw generation peak at 4.1kw today... which quite impressed me.

Anomnomnomaly
I'm only getting 3.2 kW in full blazing sunshine🤔

Cloud9 3.2kW might be a little less than ideal. On the one hand, even when the sun is perpendicular to the array, it's still at quite a low altitude, so irradiance might be down a little. On the other hand, the temperatures outside are still low, so the panels shouldn't be affected so much by high temperature. What temperature was your inverter indicating (inverter card - inverter data) during the stop-start periods? I wouldn't have expected it to be very high, maybe 45°C. Temperatures in excess of (I think) 55°C can cause it to throttle back and that's why quite a few people have added forced cooling to the underside of the passive cooling fins of the inverter.

FWIW we have 6kWp arrays on each of our HY5s and the maximum we were able to generate today in full sunshine was 5.2kW on each inverter split between battery charge and EV charge.

I'm still thinking that there's a poor connection on the PV DC for the PV current to drop when voltage is increasing.

Cloud9

What inverter?

I’m having my solaredge brand new inverter replaced as it resets under full sun. I had to dig and find the error on the inverter to eventually get solaredge to take notice. It currently won’t go any higher than 1.2kW gen before it fails. (5.5kW system). Works fine in clouds as long as sun doesn’t come out 🙂

Cloud9 What surprised me was I've actually got a 3.95kw setup, 10x395w panels and along with the 3.6kw inverter... I'm just surprised it can generate that close to it's max capacity... so to see it exceed it by about 100w was a total surprise.

I'd assumed that a 3.6kw inverter wouldn't allow it to go higher and that 4kw of panels would generate below 3.6kw in real terms.

I'm happy to be mistaken and see there's wiggle room in those figures to my benefit.

Tim
Temperature wasn't too bad, only 26°. Thanks for your thoughts👌

Tim

Where do you check the inverter temp? In the app I can only see a battery temp/voltage. So I assume it's buried away in some of the settings on the portal?

As for battery temps... highest I've seen it get is 22ºC when under a heavy charge/discharge. System is located in the garage next to the garage door and is North facing so always shaded and cooler. Panels are only a few degrees of due South... maybe as much as 6-7º, decent pitched roof, zero shading, no trees anywhere nearby... Almost perfect location for max generation. Previous house, the panels (no battery) was 16x250w on a South-East orientation, so by about 2-3pm would lose all direct light most of the year.

Anomnomnomaly
I found the temperature under inverter data. I've also noticed that there was a power spike just before it all crashEd which is very suspicious.

Cloud9 I think the "power spike" was simply the inverter ramping up as the sun increased. IMHO this increase would align with the increase in voltage and current you've already posed. However voltage continues to rise whereas current falls from just under 5A + 2.5A to less than 0.5A + 0.5A with a resulting drop in power.

I believe there's a problem with your DC connections to the inverter. It's unlikely to be somewhere along a string as they are both affected at the same time; it could be within the PV DC isolator next to the inverter if heat causes both pairs of poles to present a high resistance. After that, it'd be the inverter itself. Either way, I'd get your installer back to check their connections and give Givenergy a call to ask their advice.

Tim
Thank you Tim. I have checked through the previous few days when it has been very sunny and the same thing happened every day when it started ramping up. Everyone's tips on the way to find information has been very useful and I definitely know more about things now. I will get hold of the installers and get them to check things out. Thanks again

Cloud9

Thanks, just checked mine and overnight when idle it's sitting at 22ºC and the max it reached today was 27.3ºC