My resently installed 10kW PV 5kW Inverter with 15kW battery storage is frequently going offline in error when there is strong sunlight. The system will go offline several times during the day forcing me to import from the grid. I have been in touch with the installer but unfortunately being ignored. Any suggestions?
CamFaeFife None here but it would be down to installer if there is a fault with the system, do you call or email them typically?
Also, they installed a 10kw system with only a 5kw inverter, WTH, no wonder its going out. Is it just the one inverter you got or two, please god say two otherwise that is a MASSIVE no no from the installer.
If you phone them then they have to come and sort it out as the above install is pretty dangerous if it is what I was thinking and if they don't do it pronto id be looking at some legal action if they are just trying to ghost you, if they are actively ignoring your attempts at communication then they are in a lot of trouble.
unfortunately just one inverter. I have text messages them and sent them snapshots of the numerous error notifications and their reply was "not to worry as the inverter is oversensitive". My inverter is going offline every time I have a period of strong sun. I'm then importing from the grid until the inverter eventually resets and comes back online. I have not had a response from the installer for days despite my daily messages to them. I said that there was a mismatch with the PV and inverter. They have not replied to that.
Most solar inverters are rated in kilowatts (kW), so you’ll want to make sure you’re choosing an inverter that is equal to or greater than the wattage of your solar array.
CamFaeFife agree with the other comments about it sounds as if you have too many panels on your inverter. Can you try turning one string of panels off although this may well still overload that string.
I have 10.4kW of panels and had to have 2 5kW inverters for just that reason.
What errors are in the notifications in the GivEnergy portal ?
It might also be worth looking at the grid voltage being too high (eg other neighbours solar) that can cause your inverter to trip out if the grid voltage goes over limit. Look at the column Vac in the portal data and see if spikes above 260v correspond to Grid voltage errors
CamFaeFife yeah that is 100% not going to fly, there is no way they should be fitting panels that output twice of your inverter capacity, how stupid are they?
Id be demanding they come back with a bigger inverter to fit, preferably a 10kw one, there is no way in HELL they should have fitted a 5kw, that much current going to it I am surprised it has not done any damage yet.
Tell them that the install will need to be done properly or you will be contacting Citizens Advice about your options on how to proceed.
Have you fully paid them yet?
CamFaeFife Are all your panels on the same elevation - ie all south or are they split east west? I have a 3.6kW hybrid inverter with a total of 12 390w panels - so 4.68kWp - but split 50:50 south/west so I almost never clip (It did I think one or two days this year in June) - Not the massive disparity you have, but they may have taken that into account? (Edit) or thought they had!
4.68kw vs 3.6kw inverter on an E/W split isn't too bad it is not in the same league as 10/5 and given that west array can still generate during day whilst sun is on the east and vice versa it would still be enough to push them over the limit extremely quickly, I got 9x425 panels and ive seen it get close to 4kw on my 3.6kw inverter on a south facing array, I wouldn't trust a system capable of producing double what an inverter is rated at no matter the position personally because there is going to be a point quite frequently when its going to cause trouble.
REALLY not worth the risk.
If it is a split of directions then id at least be demanding an 8kw inverter, iirc its not supposed to be over 33% of inverter capacity, if its all south facing then I would not be settling for anything under 10.
Jellybaby Mines south/west not east west. I have seen well over 4kW at times in the summer on a good day - not forgetting that its a hybrid so can do about 6Kw - 3.6kW AC and 2.5kW DC into the battery.
anglefire my bad, got mixed up with you asking if theirs was hehe, brain is mush today
Welcome to my world!
Is it really a problem having a panel capacity bigger than the inverter? Panels don't push power, they generate a voltage and the power is determined by the current the inverter takes from them at that voltage. As long as the open circuit voltage of the panels is not above the inverter input voltage rating I don't think it shouldn't be a problem. You would just not be using the full capacity of your panels on a sunny day. The inverter would just not be drawing as much current from the panels as they could supply. You wouldn't be at the max power point.
nophead It would seem in this case it is - unless there is a split across two elevations, the inverter should be capable of the max output of the panels (Or close to it to avoid clipping)
nophead Oversizing is a thing but there is a limit to how far you should go, with a 10kw pv system id be more looking at an 8kw inverter myself personally for south facing and if it is indeed an even split on two opposite sides of a roof I wouldn't be comfortable with a 5kw, maybe pushing it up to 6.
@CamFaeFife Can you see the details of both strings like the voltage/amps and post them here, something like the following leading up to the point it cuts off.
Also what inverter do you have exactly?
Yes but clipping, while being wasteful, shouldn't cause the inverter to shut down. Most likely an over voltage fault. If it is the input voltage then there are too many cells in series in a string or perhaps the line voltage goes over.
Our export limit is set to 3.68kW for G99 approval, so in the summer we will probably be clipping as the battery can only take 2.6kW and our panels can generate 4.45kW.
nophead Well, there must be a limit somewhere. However, I suspect the majority of installations will have total panel capability above that of the inverter. Google solar installations and I doubt you will find many with panels lower than or even equal to the inverter. Those of use on the original FIT scheme alsmot all have 4kw panels and 3.6kw inverters. That was the standard installation back then. As others have said panels may not be in the ideal orientation or elevation, reducing the maximum output. The OP's system may have been sized taking into account this and even known shading.
@CamFaeFife Did you manage to get hold of them at all today?
@CamFaeFife You still having issues? Have they agreed to take a look at all? Could you post voltages for the strings when they go offline at all?